The material basis of bitter constituents in Carbonized Typhae Pollen, based on the integration strategy of constituent analysis, taste sensing system and molecular docking

The discovery of bitter constituents is of great significance to the exploration of medicinal substances for they have potential physiological effects. Carbonized Typhae Pollen (CTP), which is a typical example of carbonized Traditional Chinese Medicine (TCM), has a bitter taste and hemostatic effect after carbonized processing. The objective of this study is to elucidate the material basis of bitter constituents in CTP. Firstly, the constituents of CTP extracts with 7 different solvents were characterized by UPLC-Q-TOF-MS. Then, multivariate statistical analysis was used to visualize the CTP extracts from 7 solvents. A total of 37 constituents were tentatively identified and 17 constituents were considered as the key constituents in differentiating 7 different solvent extracts. Subsequently, the bitter evaluation of extracts from different polar parts was investigated by using an electronic tongue. As a result, the order of bitterness of the extracts was as follows: ethanol > methanol > water > n-butyl alcohol > petroleum ether > butyl acetate > isopropanol. There were statistically significant differences in the bitter degree of extracts. By correlation analysis of bitter information and chemical constituents with partial least squares regression (PLSR), 8 potential bitterness constituents were discovered, including phenylalanine, valine, chlorogenic acid, isoquercitrin, palmitic acid, citric acid, quercetin-3-O-(2-α-L-rhamnosyl)-rutinoside, and typhaneoside. Additionally, molecular docking analysis was conducted to reveal the interaction of these constituents with the bitter taste receptor. The docking result showed that these constituents could be embedded well into the active pocket of T2R46 and had significant affinity interactions with critical amino acid residues by forming hydrogen bonds. This study provided a reliable theoretical basis for future research on biological activity of bitterness substances.

Universal ion chromatography method for anions in active pharmaceutical ingredients enabled by computer-assisted separation modeling

Ion Chromatography (IC) is one of the most widely used methods for analyzing ionic species in pharmaceutical samples. A universal IC method that can separate a wide range of different analytes is highly desired as it can save a lot of time for method development and validation processes. Herein we report the development of a universal method for anions in active pharmaceutical ingredients (APIs) using computer-assisted chromatography modeling tools. We have screened three different IC columns (Dionex IonPac AS28-Fast 4 µm, AS19 4 µm and AS11-HC 4 µm) to determine the best suitable column for universal IC method development. A universal IC method was then developed using an AS11-HC 4 µm column to separate 31 most common anionic substances in 36 mins. This method was optimized using LC Simulator and a model which precisely predicts the retention behavior of 31 anions was established. This model demonstrated an excellent match between predicted and experimental analyte retention time (R2 =0.999). To validate this universal IC method, we have studied the stability of sulfite and sulfide analytes in ambient conditions. The method was then validated for a subset of 29 anions using water and organic solvent/water binary solvents as diluents for commercial APIs. This universal IC method provides an efficient and simple way to separate and analyze common anions in APIs. In addition, the method development process combined with LC simulator modeling can be effectively used as a starting point during method development for other ions beyond those investigated in this study.

Polydimethylsiloxane dialysis passive sampler monitoring of chlorinated solvent contaminated sites - A field study

The complexity of the subsurface contaminated by chlorinated solvents such as trichloroethylene (TCE) makes it challenging to gain a complete understanding of contamination distribution and establish a conceptual site model (CSM). High-resolution vertical contaminant concentration profiling across both the unsaturated zone and the saturated aquifer is desirable for mapping the distribution of contamination. A Fick's law-based polydimethylsiloxane (PDMS) dialysis passive sampler was developed and evaluated on a field scale for its potential application. This study tests the passive sampler at two TCE contaminated sites, and the sampling results were compared with the results from different sampling methods based on the relative percent difference. The PDMS dialysis passive sampler obtained more representative soil gas concentrations in the unsaturated zone than a portable monitoring and sampling device, which caused soil gas flow disturbance by soil gas pumping during sample collection. In the saturated aquifer sampling, the results obtained by the PDMS dialysis passive sampler correlated well with those obtained by a commercial polyethylene passive diffusion bag, and exhibited higher sensitivity under low TCE concentration conditions. Furthermore, the PDMS dialysis passive samplers were densely deployed inside each monitoring well at multiple depths, at two sites, to achieve high-resolution monitoring across the unsaturated zone and saturated aquifer. Based on the PDMS dialysis sampler data, a more comprehensive three-dimensional CSM was systematically established.

[Determination of six halogenated solvent residues in olive oil by headspace gas chromatography]

The residual amount of halogenated solvents in olive oil is an important indicator of its quality. The National Olive Oil Quality Standard GB/T 23347-2021 states that the residual amount of individual halogenated solvents in olive oil should be ≤0.1 mg/kg and that the total residual amount of halogenated solvents should be ≤0.2 mg/kg. COI/T.20/Doc. No. 8-1990, which was published by the International Olive Council, describes the standard method used for the determination of halogenated solvents in olive oil. Unfortunately, this method is cumbersome, has poor repeatability and low automation, and is unsuitable for the detection and analysis of residual halogenated solvents in large quantities of olive oil. At present, no national standard method for determining residual halogenated solvents in olive oil is available in China. Thus, developing simple, efficient, accurate, and stable methods for the determination of residual halogenated solvents in olive oil is imperative. In this paper, a method based on automatic headspace gas chromatography was established for the determination of residual halogenated solvents, namely, chloroform, carbon tetrachloride, 1,1,1-trichloroethane, dibromochloromethane, tetrachloroethylene, and bromoform, in olive oil. The samples were processed as follows. After mixing, 2.00 g (accurate to 0.01 g) of the olive oil sample was added into a 20 mL headspace injection bottle and immediately sealed for headspace gas chromatography analysis. Blank virgin olive oil was used to prepare a standard working solution and the external standard method for quantification. The solvents used in the preparation of halogenated solvent standard intermediates were investigated and methanol was selected as a replacement for N,N-dimethylacetamide to prepare a halogenated solvent standard intermediate owing to its safety. The effects of different injection times (1, 2, 3, 4, 5, 6 s), equilibration temperatures (60, 70, 80, 90, 100, 110, 120 ℃), and equilibration times (4, 5, 8, 10, 20, 30, 40 min) of the headspace sampler on the detection of the residual amounts of the six halogenated solvents were investigated. The optimal injection time and equilibration temperature were 3 s and 90 ℃, respectively. The method demonstrated good analytical performance for the six halogenated solvents when the equilibration time was 30 min. A methodological study was conducted on the optimized method, and the results showed that the six halogenated solvents exhibited good linear relationships in the range of 0.002-0.200 mg/kg, with correlation coefficients of ≥0.9991. The limits of detection (LODs) and quantification (LOQs) of 1,1,1-trichloroethane and bromoform were 0.0006 and 0.002 mg/kg, respectively. The LODs and LOQs of chloroform, carbon tetrachloride, dibromochloromethane, and tetrachloroethylene were 0.0003 and 0.001 mg/kg, respectively. The average recoveries under different spiked levels were 85.53%-115.93%, and the relative standard deviations (n=6) were 1.11%-8.48%. The established method was used to analyze 13 olive oil samples available in the market. Although no halogenated solvents were detected in these samples, a limited number of samples does not represent all olive oils. Hence, monitoring residual halogenated solvents in olive oil remains necessary for its safe consumption. The LOQs of the method for the six halogenated solvents were significantly lower than that of the COI/T.20/Doc. No. 8-1990 standard method (0.02 mg/kg). In addition, the developed method can be conducted under short operation times with high precision and degree of automation as well as good accuracy. Thus, the proposed method is suitable for the determination and analysis of the residues of the six halogenated solvents in large batches of olive oil samples.

Development of A Liquid-Phase Microextraction Method for Simultaneous Determination of Parabens in Lipstick Samples at Trace Levels by High-Performance Liquid Chromatography

The endocrine-disrupting potential of parabens, as well as their relation to cancer, has sparked significant discussions over their impact. Consequently, analyses of cosmetic products are an essential necessity, particularly in terms of human health and safety. In this study, a highly accurate and sensitive liquid-phase-based microextraction method was developed to determine the five parabens at trace levels by high-performance liquid chromatography. All prominent parameters of the method such as extraction solvent type and amount (1,2-dichloroethane/250 μL), and dispersive solvent type and amount (isopropyl alcohol/2.0 mL) were optimized to enhance the extraction efficiency of the analytes. The mobile phase consisting of 50 mM ammonium formate aqueous solution (pH 4.0) and acetonitrile (60:40, v/v) was used to elute the analytes at a flow rate of 1.2 mL min-1 in the isocratic mode. Analytical performance of the optimum method for methyl, ethyl, propyl, butyl and benzyl parabens were determined and the analytes recorded detection limit values of 0.78, 0.75, 0.34, 0.33 and 0.75 μg kg-1, respectively. Four different lipstick samples were analyzed under optimum conditions of the developed method, and the amount of parabens quantified in the samples using matrix matched calibration standards was in the range of 0.11-1.03%.

Fast, sustainable, and simultaneous analysis of water- and fat-soluble vitamins by the two-dimensional microcarbon fiber fractionation system hyphenated with MS detection

BACKGROUND

Vitamins are micronutrients that are required for normal growth and development of living organisms. However, due to their various chemical properties (e.g., acid-base behavior, the presence of numerous forms) and fluctuating concentration levels within complex matrices, simultaneous analysis of multi-class vitamins, including their active forms, is a challenging task. The growing nutrient shortage in foods is concerning for food consumers, manufacturers, and quality control organizations. Hence, a simple, fast, and greener approach that can simultaneously analyze multi-class vitamins is required to aid food testing and clinical laboratories in evaluating vitamin content more rapidly and accurately.

RESULTS

A green and rapid analytical method based on online two-dimensional microscale carbon fiber/activated carbon fiber fractionation-mass spectrometry (2DμCFs-MS) was developed and validated for simultaneous determination of vitamins (water- and fat-soluble vitamins and some analogs) in food supplements and fortified energy drinks. Vitamins have been successfully separated into three different fractions using the minimum toxic solvent (only 0.7 mL of organic solvent) in a single run within 6 min. The limit of detection (LOD) ranges from 0.1 to 10.4 ng/mL, and the limit of quantification (LOQ) ranges from 0.39 to 34.5 ng/mL. The method also showed adequate repeatability and intermediate precision, with RSD<10 % and R2 > 0.99 for most vitamins. The analytical method was evaluated in terms of greenness, with an analytical greenness (AGREE) score of 0.68.

SIGNIFICANCE

The 2DμCFs-MS system was developed to separate and detect multi-class vitamins simultaneously, which can be used as a beneficial tool to investigate vitamin content for food labeling and determining the vitamins in biological fluids and other complex samples. The developed method can tackle the challenge of simultaneous and fast routine analysis of multi-class vitamins.

Extraction and preconcentration of parabens from the human follicular fluid through dispersive micro solid phase extraction using microporous MIL-68 (In) followed by in-situ effervescence-boosted dispersive liquid-liquid microextraction

For the first time in this study, a microextraction method was developed to perform follicular fluid safety assessment analysis. The drastic importance of follicular fluid safety on the proper nourishment and development of oocytes caused the development of the present method. Since women are regularly exposed to parabens through cosmetics, healthcare, and hygienic products, the infection of body fluids is probable in long-term exposures. Also, for the first time, MIL-68 (In) was applied in an analytical method. Moreover, a new method called in-situ effervescence-boosted dispersive liquid-liquid microextraction was adopted for the simultaneous derivatization and preconcentration of the target parabens. To perform the method, 25 mg of MIL-68 (In) was dispersed into the solution of follicular fluid by vortexing. Then, 1.0 mL of 2-propanol was used to elute the analytes from the absorbent via vortexing. The analyte-enriched organic phase was mixed with 100 µL of acetic anhydride (derivatization agent) and 27 µL 1,2-dibromoethane (extraction solvent) which was swiftly injected into a sodium carbonate solution. Following the centrifugation, the extraction solvent was sedimented at the bottom of a conical bottom glass test tube and an aliquot of it was injected into a gas chromatograph equipped with a flame ionization detector. Wide linear ranges (120-25000 µg L-1), satisfactory extraction recoveries (31-79%) and enrichment factors (31-79), and appreciable limits of detection (7-36 µg L-1) and quantification (25-120 µg L-1) were recorded. The high surface area of MIL-68 (In) (608.82 m2 g-1) and its significantly low average pore diameter (13.829 A°) provide an ideal platform for the extraction of parabens from the complex matrix of follicular fluid.

[Determination of three new herbicide residues in soil, sediment and water by liquid chromatography-tandem mass spectrometry]

Herbicides play an important role in preventing and controlling weeds and harmful plants and are increasingly used in agriculture, forestry, landscaping, and other fields. However, the effective utilization rate of herbicides is only 20%-30%, and most herbicides enter the atmosphere, soil, sediment, and water environments through drift, leaching, and runoff after field application. Herbicide residues in the environment pose potential risks to ecological safety and human health. Therefore, establishing analytical methods to determine herbicide residues in environmental samples is of great importance. In this study, an analytical method based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) in positive electrospray ionization mode (ESI+) was developed for the determination of isoxaflutole, metazachlor, and saflufenacil residues in soil, sediment, and water. The instrumental detection parameters, including electrospray ionization mode, mobile phase, and chromatographic column, were optimized. The mobile phases were methanol (A) and 0.1% formic acid aqueous solution (B). Gradient elution was performed as follows: 0-1.0 min, 60%A; 1.0-2.0 min, 60%A-90%A; 2.0-3.0 min, 90%A; 3.0-4.0 min, 90%A-60%A; 4.0-5.0 min, 60%A. The samples were salted after extraction with acetonitrile and cleaned using a C18 solid-phase extraction column. Different solid-phase extraction columns and leaching conditions were investigated during sample pretreatment. Working curves in the neat solvent and matrix were constructed by plotting the measured peak areas as a function of the concentrations of the analytes in the neat solvent and matrix. Good linearities were found for isoxaflutole, metazachlor, and saflufenacil in the solvent and matrix-matched standards in the range of 0.0005-0.02 mg/L, with r≥0.9961. The matrix effects of the three herbicides in soil, sediment, and water ranged from -10.1% to 16.5%. The limits of detection (LODs, S/N=3) for isoxaflutole, metazachlor, and saflufenacil were 0.05, 0.01, and 0.02 μg/kg, respectively. The limits of quantification (LOQs, S/N=10) for isoxaflutole, metazachlor, and saflufenacil were 0.2, 0.05, and 0.05 μg/kg, respectively. The herbicides were applied to soil, sediment, and water at spiked levels of 0.005, 0.1, and 2.0 mg/kg, respectively. The average recoveries for isoxaflutole, metazachlor, and saflufenacil in soil, sediment, and water were in the ranges of 77.2%-101.9%, 77.9%-105.1%, and 80.8%-107.1%, respectively. The RSDs for isoxaflutole, metazachlor, and saflufenacil were in the ranges of 1.4%-12.8%, 1.2%-7.7%, and 1.5%-11.5%, respectively. The established method was used to analyze actual samples collected from four different sites in Zhejiang Province (Xiaoshan, Taizhou, Dongyang, and Yuhang) and one site in Heilongjiang (Jiamusi). The proposed method is simple, rapid, accurate, stable, and highly practical. It can be used to detect isoxaflutole, metazachlor, and saflufenacil residues in soil, sediment, and water and provides a reference for monitoring the residual pollution and environmental behavior of herbicides.

Groundwater chlorinated solvent plumes remediation from the past to the future: a scientometric and visualization analysis

Contamination of groundwater with chlorinated hydrocarbons has serious adverse effects on human health. As research efforts in this area have expanded, a large body of literature has accumulated. However, traditional review writing suffers from limitations regarding efficiency, quantity, and timeliness, making it difficult to achieve a comprehensive and up-to-date understanding of developments in the field. There is a critical need for new tools to address emerging research challenges. This study evaluated 1619 publications related to this field using VOSviewer and CiteSpace visual tools. An extensive quantitative analysis and global overview of current research hotspots, as well as potential future research directions, were performed by reviewing publications from 2000 to 2022. Over the last 22 years, the USA has produced the most articles, making it the central country in the international collaboration network, with active cooperation with the other 7 most productive countries. Additionally, institutions have played a positive role in promoting the publication of science and technology research. In analyzing the distribution of institutions, it was found that the University of Waterloo conducted the majority of research in this field. This paper also identified the most productive journals, Environmental Science & Technology and Applied and Environmental Microbiology, which published 11,988 and 3253 scientific articles over the past 22 years, respectively. The main technologies are bioremediation and chemical reduction, which have garnered growing attention in academic publishing. Our findings offer a useful resource and a worldwide perspective for scientists engaged in this field, highlighting both the challenges and the possibilities associated with addressing groundwater chlorinated solvent plumes remediation.

Field demonstration for the solvent-based sampling method to perform compound-specific isotope analysis on gas-phase VOC

The solvent-based sampling method for collecting gas-phase volatile organic compounds (VOCs) and conducting compound-specific isotope analysis (CSIA) was deployed during a controlled field study. The solvent-based method used methanol as a sink to accumulate petroleum hydrocarbons during the sampling of soil air and effluent gas. For each gaseous sample collected, carbon isotope analysis (δ13C) was conducted for a selection of five VOCs (benzene, toluene, o-xylene, cyclopentane and octane) emitted by a synthetic hydrocarbon source emplaced in the subsurface. The δ13C values obtained for gaseous VOCs (collected from soil gas and effluent gas) were compared to measurements obtained for the same VOCs present in the source material (none aqueous phase liquid - NAPL) and dissolved in groundwater to evaluate the reliability of the solvent-based sampling method in providing accurate isotope measurements. Since the NAPL source was composed of only 12 VOCs, potential bias related to the analytical procedure (such as co-elution) were avoided, hence emphasizing on field-related bias. This field evaluation demonstrated the capacity of the solvent-based method to produce precise and accurate δ13C measurements. The isotopic discrepancies between the gaseous and the NAPL values were < 1 ‰ for 39 out of the 41 comparison points, thus deemed not statistically different based on a common isotopic uncertainty error of ±0.5 ‰. Moreover, the current field study is the first field study to report δ13C measurements for up to five gas-phase VOCs obtained from the same sample, which appears to be of interest for VOC fate or forensic studies. The possibility to use several VOC isotopic measurements enabled by the sampling method would contribute to strengthen the connection assessment between gaseous VOCs and the suspected emitting source. Accordingly, the field results presented herein support the application of this sampling methodology to conduct CSIA assessment in the frame of VOC vapor studies.

Facile construction of magnetic solid-phase extraction of polyaniline blend poly(amidoamine) dendrimers modified graphene oxide quantum dots for efficient adsorption of polycyclic aromatic hydrocarbons in environmental water

An efficient magneto-adsorbent composed of polyaniline blend poly(amidoamine) dendrimers modified graphene oxide quantum dots and magnetic Fe3O4 particles (Fe3O4@PANI-PSS/PAMAM-QGO) for magnetic solid-phase extraction (MSPE) of polycyclic aromatic hydrocarbons (PAHs) in environmental water was synthesized. Fe3O4@PANI-PSS/PAMAM-QGO exhibited exceptional adsorption property for most PAHs analytes. The nanocomposite sorbent demonstrated a ferromagnetic behavior of 17.457 emu g-1, which is adequate for subsequent use in MSPE. Key parameters affecting the processes of adsorption and desorption, including the sorbent amount, vortex adsorption time, vortex extraction time, sample volume, a solvent for desorption and the solvent volume were all examined and optimized. The performance of MSPE using Fe3O4@PANI-PSS/PAMAM-QGO as adsorbent for four PAHs, including fluoranthene, acenaphthene, phenanthrene and pyrene were studied through high performance liquid chromatography equipped with spectrofluorometer. Under the optimal conditions, Fe3O4@PANI-PSS/PAMAM-QGO showed a wide linearity of 10-1,000 ng mL-1, low detection limit (LOD) ranging from 1.92 to 4.25 ng mL -1 and high accuracy (recoveries of 93.6-96.5 %). Enrichment factors up to 185 were achieved. Furthermore, Fe3O4@PANI-PSS/PAMAM-QGO exhibited good recyclability (10 times, RSDs ≤ 5.35%), while maintaining its high efficiency in the extraction of PAHs. The proposed method was successfully applied for environmental samples. Recoveries ranging from 81.2 to 106.2 % were obtained, indicating a low matrix effect and the robustness of the optimized MSPE method. Based on these features and under the optimal extraction conditions, Fe3O4@PANI-PSS/PAMAM-QGO was demonstrated to be a successful tool for the rapid and sensitive extraction of PAHs in the samples.

Biomonitoring of Exposures to Solvents and Metals in Electronics Manufacturing Facilities in Batam, Indonesia

Concerns about chemical exposure in the electronics manufacturing industry have long been recognized, but data are lacking in Southeast Asia. We conducted a study in Batam, Indonesia, to evaluate chemical exposures in electronics facilities, using participatory research and biological monitoring approaches. A convenience sample of 36 workers (28 exposed, 8 controls) was recruited, and urine samples were collected before and after shifts. Five solvents (acetone, methyl ethyl ketone, toluene, benzene, and xylenes) were found in 46%-97% of samples, and seven metals (arsenic, cadmium, cobalt, tin, antimony, lead, and vanadium) were detected in 60%-100% of samples. Biological monitoring and participatory research appeared to be useful in assessing workers' exposure when workplace air monitoring is not feasible due to a lack of cooperation from the employer. Several logistical challenges need to be addressed in future biomonitoring studies of electronics workers in Asia in factories where employers are reluctant to track workers' exposure and health.

Synthesis of an ordered macroporous metal-organic framework for efficient solid-phase extraction of aflatoxins from milk products

Aflatoxins (AFs) exhibit hepatotoxicity, immunotoxicity, and carcinogenicity, and their detection in food has attracted widespread concern. An ordered macroporous metal-organic framework (OM-ZIF-8) based on solid-phase extraction (SPE) was used to extract six AFs from milk products. The SPE conditions, including eluting solvent, eluting volume, amounts of OM-ZIF-8, pH of loading solution, loading solvent, ionic strength, loading flow rate, and elution flow rate, were exhaustively optimized. Under optimal parameters, the six AFs were detected by ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The OM-ZIF-8 exhibited satisfactory AFs extraction performance through ordered macropore structure, π-π interaction, coordination interaction, and electrostatic interaction. Furthermore, linearity in the range of 0.01-100 ng mL-1 with low detection limits of 0.002-0.0150 ng mL-1 was obtained, and the relative recoveries of AFs were 80.3-110 % with relative standard deviation ≤8.7 %. Thus, this research provides a promising platform for the analysis of trace AFs in complex foods.

Simultaneous extraction, separation, and analysis of 5-caffeoylquinic acid and caffeine from coffee co-product by PLE-SPE × HPLC-PDA two-dimensional system

This study proposed an integrated and automated procedure to extract, separate, and quantify bioactive compounds from a coffee co-product by pressurized liquid extraction (PLE) coupled inline with solid phase extraction (SPE) and online with HPLC-PDA (PLE-SPE × HPLC-PDA). The efficiency of the two-dimensional system in performing real-time analysis was verified by comparing HPLC-PDA results acquired by the system (online) and carried out after the extract fraction collection (offline). Different flow rates (1.5 mL/min for 336 min, 2 mL/min for 246.4 min, and 2.5 mL/min for 201.6 min) were evaluated to optimize the extraction, separation, and analysis method by PLE-SPE × HPLC-PDA. Subcritical water at 125 °C and 15 min of static time allowed the highest extraction yields of caffeine and 5-caffeoylquinic acid (5-CQA). Caffeine was retained during the aqueous extraction in the SPE adsorbent and eluted from the column by exchanging the solvent for a hydroethanolic mixture. Thus, caffeine was separated from 5-CQA and other phenolic compounds, producing extracts with different compositions. The solvent flow rate did not have a significant effect (p-value ≥ 0.05) on the extraction, separation, and analysis (by online and offline methods) of 5-CQA. However, the online quantification of retained compounds in the SPE (i.e., caffeine) can underestimate concentration compared to offline analysis. Nevertheless, the results suggest that coupling of advanced techniques can be used to efficiently extract, separate, and analyze fractions of phenolic compounds, supplying an integrated method to produce high-added value ingredients for several applications.

Recovery of Phenolic Compounds from Orange Peel Waste by Conventional and Assisted Extraction Techniques Using Sustainable Solvents

BACKGROUND

The valorization of orange peel waste (OPW) through the extraction of bioactive compounds is a clear example of the circular economy. OPW contains many value-added compounds, among which bioactive phenolic compounds (flavonoids and phenolic acids) could be extracted and used for industrial applications, such as pharmaceuticals or cosmetics.

METHODS

In this work, the extraction of phenolic compounds from orange peel was carried out by conventional (orbital shaker) and assisted (ultrasound and microwave) extraction techniques using deionized water, 80% (v/v) ethanol in water, and ethyl acetate as solvents. The effect of temperature, extraction time, and type of technique was evaluated and discussed following spectrophotometric (total phenolic content and total flavonoid content) and high-performance liquid chromatography (HPLC) analyses of the extracts.

RESULTS

The most effective extraction in terms of efficiency was achieved by microwave-assisted extraction using 80% (v/v) ethanol in water as the extraction solvent, at 373 K for 6 min, which obtained 7.2 ± 0.1 mg gallic acid equivalent (GAE)/g OPW and 13.3 ± 0.1 mg quercetin equivalent (QE)/g OPW, with the main bioactive compound extracted being hesperidin (58.2 ± 0.2 mg/g OPW). The most effective extraction in terms of energy consumption was achieved using ultrasound-probe-assisted extraction, yielding 8.8 ± 0.0 mg GAE/g OPW; 17.1 ± 0.1 mg QE/g OPW; 40.0 ± 0.2 mg hesperidin/g OPW, with an energy consumption of 18 kJ.

CONCLUSIONS

Ultrasound and microwave-assisted extractions can be considered efficient extraction technologies for the valorization of OPW as they reduce extraction time and energy consumption and increase extraction yield.

Determination of Volatile Organic Compounds and Endogenous Extracts and Study of Expression Patterns of TPS and BSMT in the Flowers of Seven Lilium Cultivars

Lily is one of the most important cut flowers in the world, with a rich floral fragrance. To further explore the fragrance emission mechanisms of lily cultivars, headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) and organic solvent extraction-gas chromatography-mass spectrometry (OSE-GC-MS) were used to unveil the volatile organic compounds (VOCs) and endogenous extracts of seven lily cultivars. Furthermore, real-time quantitative PCR (qRT-PCR) was used to determine the expression levels of two key genes (TPS and BSMT) related to the biosynthesis of monoterpenoids and methyl benzoate. The results show that forty-five VOCs were detected in the petals of seven lily cultivars, and the main compounds were monoterpenoids and phenylpropanoids/benzenoids. Dichloromethane was the best solvent for extracting the endogenous extracts of Lilium 'Viviana' petals and eighteen endogenous extracts were detected using dichloromethane to extract the petals of seven lily cultivars. Each compound's emission ratio (natural logarithm of the ratio of VOC content to endogenous extract content) was calculated, and linear regression analyses between emission ratios and boiling points were conducted. Significant linear negative correlations existed between the emission ratios and boiling points of compounds, and the regression equations' coefficients of determination (R2) were all greater than 0.7. TPS was expressed highly in 'Viviana', 'Pink News', and 'Palazzo', and BSMT was expressed highly in 'Pink News' and 'Palazzo'. Correlation analyses between the gene expression levels and the monoterpenoids and methyl benzoate contents found that the TPS expression levels have strong positive correlations with monoterpenoids content, while no correlations were found between the expression levels of BSMT and the contents of methyl benzoate. This study lays the foundation for research on the release patterns of VOCs in the flowers of Lilium, and the breeding of lilies for their floral fragrance.

Measurement of fluorotelomer alcohols based on solid phase microextraction followed by gas chromatography-mass spectrometry and its application in solid waste study

This work developed a method based on solid phase microextraction followed by gas chromatography/mass spectrometry (SPME-GC/MS) for the measurement of fluorotelomer alcohols (FTOHs) in gas samples. The method quantification limit (MQL) is 6-7 ng/L for 6:2 fluorotelomer alcohols (6:2 FTOH) and 8:2 fluorotelomer alcohols (8:2 FTOH). In contrast to common methods such as thermal desorption combined with GC-MS, it needs neither pre-concentration equipment nor large sample volume. The extraction-evaporation-GC/MS is commonly used in literature for FTOHs measurement in solids samples. We developed a method to measure FTOHs in solid samples by adding solvent extraction prior to headspace SPME-GC/MS. The extraction-headspace SPME-GC/MS method has a quantification limit of 40-43 ng per gram for 6:2 FTOH and 8:2 FTOH in solid samples. This is comparable to the MQLs for the extraction-evaporation-GC/MS method. Removing the solvent evaporation step decreased the risk of contamination and loss of analytes. The developed methods were successfully used in three examples of solid waste study: 1) measuring 6:2 FTOH and 8:2 FTOH above the MQL in gas emissions from a closed landfill, 2) finding 6:2 FTOH above MQL in 9 of 31 solid consumer products, and 3) finding that the release of 6:2 FTOH in simulated landfills containing popcorn bags was linear at a rate of 3.15 ng/g popcorn bags-day and that partial 6:2 FTOH was from the hydrolysis of precursors.

Ultrasound-assisted extraction followed by liquid chromatography coupled to tandem mass spectrometry for the simultaneous determination of multiclass herbicides in soil

An analytical methodology based on ultrasound-assisted extraction (UAE) followed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) has been developed for the identification and quantification of 9 authorized herbicides in soil (dimethenamid-P, imazamox, S-metolachlor, nicosulfuron, pendimethalin, prosulfuron, bentazone, terbuthylazine, and mesotrione). Preliminary experiments dealing with solvent extraction, the extraction technique, and herbicide response comparison in soil, with and without organic amendments, were carried out with the purpose of obtaining high sample throughput and sensitivity. UAE and the solvent mixture water:methanol demonstrated higher efficiency and they were selected as sample treatment and extraction solvent, respectively. Critical parameters affecting UAE were optimized by experimental design. In the present research, the extraction technique used in the official EPA microwave-assisted extraction (MAE) methodology (United States Environmental Protection Agency) and UAE optimized methodology were compared. The results indicated that the developed method showed better efficacy since microwave extraction gave very poor responses for nicosulfuron and prosulfuron. The temperature extraction was also optimized; room temperature was the most suitable to work with. Under the optimized conditions, the proposed UAE-LC-MS/MS method was assessed in terms of linearity (R2 ≥ 0.9912), accuracy (recoveries around 100%), and precision (relative standard deviation, RSD < 13%). The absence of significant matrix effects allowed quantification in real samples by external calibration with standards prepared in water:methanol. Method sustainability was also evaluated using the metric tool AGREEPrep. Finally, the analysis of real contaminated samples revealed the presence of 7 out of the 9 studied herbicides with S-metolachlor at high concentrations in all samples.

[Rapid detection of four amphetamine-type drugs in hair by pulsed direct current electrospray mass spectrometry]

Amphetamine-type drugs are synthetic compounds with an amphetamine parent structure. These compounds cause addiction, central nervous system excitation, and hallucinations. The number of drug users worldwide has gradually increased because amphetamine-type drugs can be synthesized in a simple and artificial manner. The current methods for anti-drug screening and toxicant identification are limited by the large quantity and variety of the drug analytes and long detection times. Thus, the development of broad-spectrum, rapid, and high-throughput detection methods is an urgent necessity. In addition, conventional amphetamine-type drug test samples, such as blood and urine, are only suitable for short-term drug identification. Hair has the advantages of easy preservation, stability, and a long detection window, which can compensate for the deficiencies of body-fluid-based test materials. Hair samples can reflect long-term drug use, which is beneficial for tracing drug sources, and has become an important means of providing evidence in court. Because most laboratory instruments are unable to perform the rapid on-site detection of amphetamine-type drugs in hair, establishing a high-throughput, qualitative and quantitative rapid on-site detection method is necessary. In this study, pulsed direct current electrospray ionization (Pulsed-DC-ESI) coupled with mass spectrometry was used for the rapid detection of four amphetamine-type drugs (amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine, and 3,4-methylenedioxymethamphetamine) in hair. Methanol was used as the extraction solvent, and the grinding method was used for extraction. The pretreatment process included cutting, grinding, and centrifugation. The pretreatment time for each sample was about 10 min. Multiple samples could be processed in batches, greatly improving the efficiency of analysis. Pulsed-DC-ESI is an ambient ionization technology that can be conducted via direct injection without chromatographic separation. The tip of the spray capillary tube was immersed 1 cm below the surface of the sample solution to allow absorption via the capillary effect. When the spray capillary tube contained 1 μL of the sample solution, detection was performed. Pulsed-DC-ESI generates an electrospray at the same frequency as the mass spectrum, thereby avoiding the problem of sample wastage, which often occurs in traditional ESI. The portable mass spectrometer used for analysis is a linear ion trap mass spectrometer. The parameters of Pulsed-DC-ESI, such as the inner diameter of spray capillary tip, spray voltage, and distance between electrode and solution, were optimized based on the mass spectral responses of the amphetamine-type drugs. The optimized ion source conditions included a inner diameter of spray capillary tip of 25 μm, spray voltage of 2 kV, and the distance between electrode and solution of 20 mm. The optimal sample solvent was methanol. The optimized method can achieve simultaneous detection of the four amphetamine-type drugs within 20 s. The linear ranges of amphetamine, methamphetamine, and the two other drugs were 1-25, 1-100, and 1-50 ng/mg, respectively. The limits of detection and quantification of the four drugs in hair were 0.1-0.2 and 1 ng/mg, respectively. All linear correlation coefficients were greater than 0.99, and the average spiked recoveries were 86.6%-114.7%. The intra-day precisions were 4.14%-7.34%, and the inter-day precisions were 3.71%-8.43%. The proposed method was used to screen 2000 samples provided by various testing institutions. A total of five samples were positive for methamphetamine, which is consistent with the results of conventional forensic identification methods. Thus, the developed method can be used for the rapid detection of amphetamine-type drugs.

UPLC/ESI/MS profiling of red algae Galaxaura rugosa extracts and its activity against malaria mosquito vector, Anopheles pharoensis, with reference to Danio rerio and Daphnia magna as bioindicators

BACKGROUND

Anopheles pharoensis has a major role in transmitting several human diseases, especially malaria, in Egypt?. Controlling Anopheles is considered as an effective strategy to eliminate the spread of malaria worldwide. Galaxaura rugosa is a species of red algae found in tropical to subtropical marine environments. The presence of G. rugosa is indicative of the ecosystem's overall health. The current work aims to investigate UPLC/ESI/MS profile of G. rugosa methanol and petroleum ether extracts and its activity against An. pharoensis and non-target organisms, Danio rerio and Daphnia magna.

METHODS

Galaxaura rugosa specimens have been identified using DNA barcoding for the COI gene and verified as G. rugosa. The UPLC/ESI/MS profiling of G. rugosa collected from Egypt was described. The larvicidal and repellent activities of G. rugosa methanol and petroleum ether extracts against An. pharoensis were evaluated, as well as the toxicity of tested extracts on non-target organisms, Dan. rerio and Dap. magna.

RESULTS

The UPLC/ESI/MS analysis of methanol and petroleum ether extracts led to the tentative identification of 57 compounds belonging to different phytochemical classes, including flavonoids, tannins, phenolic acids, phenyl propanoids. Larval mortality was recorded at 93.33% and 90.67% at 80 and 35 ppm of methanol and petroleum ether extracts, respectively, while pupal mortality recorded 44.44 and 22.48% at 35 and 30 ppm, respectively. Larval duration was recorded at 5.31 and 5.64 days by methanol and petroleum ether extracts at 80 and 35 ppm, respectively. A decrease in acetylcholinesterase (AChE) level and a promotion in Glutathione-S-transferase (GST) level of An. pharoensis 3rd instar larvae were recorded by tested extracts. The petroleum ether extract was more effective against An. pharoensis starved females than methanol extract. Also, tested extracts recorded LC50 of 1988.8, 1365.1, and 11.65, 14.36 µg/mL against Dan. rerio, and Dap. magna, respectively.

CONCLUSIONS

Using red algae derivatives in An. pharoensis control could reduce costs and environmental impact and be harmless to humans and other non-target organisms.

Bioactive compounds recovery by freeze concentration process from winemaking by-product

Grape pomace is the main solid residue of wine industry, containing high amounts of phenolic compounds. Considering its high potential, an extraction procedure was optimized for maximal recovery of anthocyanins from grape pomace (Vitis vinifera L.) using citric acid as a generally recognized as safe (GRAS) acidulant in water. Volume of solvent (3.2-36.8 mL), time (14.4-165.6 min) and pH of solvent (1.12-4.48) were the studied variables. Furthermore, the best condition to obtain extract rich in anthocyanins was submitted to the gravitational block freeze concentration process. The performance of the process was evaluated and cryoconcentrated and ice fractions were analyzed for physicochemical properties, bioactive compounds content, and antioxidant activity. Interaction, linear, and quadratic effects for volume and pH of solvent were significant by analysis of variance (ANOVA). The experimental design allowed the prediction for maximal recovery of anthocyanins (10 mL of solvent at pH 1.8). The bioactive composition of the optimized grape pomace extract was influenced by the cryoconcentration process. After three cycles using gravitational block freeze concentration, the total phenolics and monomeric anthocyanins were approximately 4 and 5 times higher than the initial condition of the extract, respectively. Consequently, an increase in antioxidant activity was observed. The increase in the concentration of bioactive compounds reached a process efficiency of 93% (stage 1) for phenolic compounds and 91% (stage 2) for anthocyanins. Therefore, the final water-based optimized method is safe and has a low cost and the concentrated extract certainly showed higher concentrations of total phenolics and anthocyanins, compared to the initial extract. The proposed clean extraction method and cryoconcentration technique can be considered important strategies for recovering and valuing grape pomace components, improving the approach to the circular economy concept in the wine industry.

Facile extraction of berberine from different plants, separation, and identification by thin-layer chromatography, high-performance liquid chromatography, and biological evaluation against Leishmaniosis

The extraction of berberine was carried out from Berberis vulgaris, Berberis aquifolium, and Hydrastis canadensis plants using ethanol and water (70:30, v/v). The extracted berberine was characterized by ultraviolet-visible and Fourier-transform infrared spectroscopy. The purity of berberine was ascertained by thin-layer chromatography using n-propanol-formic acid-water (95:1:4) and (90:1:9) solvents. hRf values were in the range of 44-49 with compact spots (diameter 0.2-0.4 cm). HPLC was carried out using ammonium acetate buffer and acetonitrile in gradient mode with Zodiac (4.6 × 150 mm, 3 μm) column. The flow rate was 1.0 mL/min and detection was at 220 nm. The values of separation and resolution factors of the standard and the extracted berberine were in the range of 1.13-1.16 and 1.40-1.71, respectively. A comparison has shown that both thin-layer chromatography and high-performance liquid chromatography (HPLC) methods found applications in different situations and requirements. The extracted berberine samples were used to treat Leishmaniosis and the results showed better activity of berberine in comparison to the standard drug Amphotericin B. Briefly, the reported research is a novel and may be used to extract berberine from plants, separation and identification of berberine by thin layer chromatography and HPLC and to treat Leishmaniosis.

Deep eutectic solvents as an alternative for extraction of flavonoids from soybean (Glycine max (L) Merrill) and okara: An experimental and computational approach based on COSMO-SAC model

In this study, different Deep Eutectic Solvents based on choline chloride ([Ch]Cl) with carboxylic acids, sugars, and glycerol, were investigated as alternative solvents for the extraction of flavonoids from soybean and okara. Initially, the COSMO-SAC was investigated as a tool in solvent screening for the extraction of flavonoids. Experimental validation was performed using total flavonoid analysis with the solvents that showed greater interaction with the solutes. The extracts obtained from soybean and okara using the DES [Ch]Cl:acetic acid added with 30 % water showed the highest total flavonoid content, 1.05 mg eq. of catechin/g dry soybean and 0.94 mg eq. of catechin /g dry okara, respectively. For phenolic compound extraction, [Ch]Cl: acetic acid DES extracted approximately 1.16 mg GAE/g of soybean and 0.69 mg GAE/g of okara. For antioxidant activity, soybean and okara extracts obtained with [Ch]Cl: acetic acid showed FRAP results of 0.40 mg Trolox/mL of extract and 0.45 mg Trolox/mL of extract, respectively. In addition, the isoflavones daidzein, genistein, glycitein, daidzin, genistin, and glycitin were identified and quantified in the soybean and okara extracts obtained with DES [Ch]Cl: acetic acid with 30% water, totaling 1068.05 and 424.32 µg total isoflavones/g dry sample. Therefore, The COSMO-SAC model was a useful tool in solvent screening, saving time and costs. Also, DES can be an alternative solvent for extracting flavonoids to replace conventional organic solvents, respecting current environmental and human health concerns.

Application of one-step inner-recycling counter-current chromatography for the preparative separation and purification of chemical constituents from the rhizome of Bergenia ciliate (haw.) Sternb

Bergenia ciliata (haw.) Sternb, the renowned pharmaceutical plant in Jammu and Kashmir of Pakistan, is widely applied in treating different illnesses including diabetes, diarrhea, and vomiting. This work employed an efficient one-step inner-recycling counter-current chromatography for preparative separating and purifying compounds with similar partition coefficients from the rhizome of Bergenia ciliate (haw.). Five compounds, including quercetin rhamnodiglucoside (1), quercetin-3-O-rutinoside (2), bergenine (3), kaempferol (4), and palmatic acid (5), were successfully separated using the optimized biphasic solvent system that contained ter-butylmetylether/n-butanol/acetonitrile/water (2:2:1:5, v/v) with the purities over 98%. Mass spectrometry and nuclear magnetic resonance were conducted for structural identification. As a result, our proposed strategy might be applied in separating compounds with similar partition coefficients, which was advantageous with regard to the less solvent and time consumption, and the increased number of theoretical plates.

Rapid, efficient, and green analytical technique for determination of fluorotelomer alcohol in water by stir bar sorptive extraction

Fluorotelomer alcohols (FTOHs) are one of the major classes of per- and polyfluoroalkyl substances (PFAS). Due to their potential toxicity, persistence, and ubiquitous presence in the environment, some common PFAS are voluntarily phased out; while FTOHs are used as alternatives to conventional PFAS. FTOHs are precursors of perfluorocarboxylic acids (PFCAs) and therefore they are commonly detected in water matrices, which eventually indicate PFAS contamination in drinking water supplies and thus a potential source of human exposure. Even though studies have been conducted nationwide to evaluate the degree of FTOHs in the water environment, robust monitoring is lacking because of the unavailability of simple and sustainable analytical extraction and detection methods. To fill the gap, we developed and validated a simple, rapid, minimal solvent use, no clean-up, and sensitive method for the determination of FTOHs in water by stir bar sorptive extraction (SBSE) coupled with thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS). Three commonly detected FTOHs (6:2 FTOH, 8:2 FTOH, and 10:2 FTOH) were selected as the model compounds. Factors such as extraction time, stirring speed, solvent composition, salt addition, and pH were investigated to achieve optimal extraction efficiency. This "green chemistry" based extraction provided good sensitivity and precision with low method limits of detection ranging from 2.16 ng/L to 16.7 ng/L and with an extraction recovery ranging 55%-111%. The developed method were tested on tap water, brackish water, and wastewater influent and effluent. 6:2 FTOH and 8:2 FTOH were detected in two wastewater samples at 78.0 and 34.8 ng/L, respectively. This optimized SBSE-TD-GC-MS method will be a valuable alternative to investigate FTOHs in water matrices.

Cork sheet as an efficient biosorbent for forensic toxicology: Application to vitreous humor analysis

There is an increasing number of people affected worldwide by mental health disorders, such as depression and anxiety. One of the main courses of treatment, along with psychotherapy, is the use of psychoactive medications, like antidepressants and benzodiazepines. Also, the unprescribed use of these substances is a concerning public health issue. Hence, the analysis of psychotropic medications is mandatory in postmortem toxicology and various biological samples can be used for this detection, among them the vitreous humor (VH) stands out. Also, there is a demand for more sustainable and more efficient extraction methodologies according to green chemistry. An example is solid phase microextraction techniques (SPME), which use a solid sorbent and small solvent amounts. Biosorbents are substances of natural origin with sorptive properties, and they have been successfully used in SPME in environmental toxicology for water analysis, mainly. This study aimed to develop a sustainable, fast, cheap and simple SPME methodology using cork sheet strips as a biosorbent, to extract antidepressants, benzodiazepines and others from VH samples by liquid chromatography coupled to tandem mass spectrometry. The extraction was conducted in a 96-well plate using 200 µL of VH and optimization of relevant parameters for extraction was performed. For solvent optimization, two simplex-centroid experiments were planned for extraction and desorption and to evaluate time and pH, a Doehlert design experiment was performed. The analytical method for the determination and quantification of 17 substances was validated. The quantification limits were 5 ng/mL for all analytes and the calibration curves were linear between 5 and 30 ng/mL. This study was able to develop an efficient, cheap, simple and fast microextraction method for 17 analytes in VH, using strips of cork sheet for extraction and a 96-well plate as a container. Furthermore, this approach system could be automated for routine toxicology laboratories.

Analysis of Pesticide Residues on Fruit Using Swab Spray Ionization Mass Spectrometry

The vast quantity and high variety of pesticides globally used in agriculture entails considerable risks for the environment and requires ensuring the safety of food products. Therefore, powerful analytical tools are needed to acquire qualitative and quantitative data for monitoring pesticide residues. The development of ambient ionization mass spectrometry methods in the past two decades has demonstrated numerous ways to generate ions under atmospheric conditions and simultaneously to reduce the need for extended sample preparation and circumvent chromatographic separation prior to mass analysis. Swab spray ionization enables the generation of ions directly from swabs via the application of high voltage and solvent flow. In this study, swab sampling of fruit surfaces and subsequent ionization directly from the swab in a modified electrospray ion source was employed for the screening and quantitation of pesticide residues. Aspects regarding sample collection, sampling efficacy on different surfaces, and swab background are discussed. The effect of solvent composition on pesticide-sodium adduct formation and the suppression of ionization by the background matrix have been investigated. Furthermore, a novel approach for the quantitation of pesticide residues based on depletion curve areas is presented. It is demonstrated that swab spray ionization is an effective and quick method for spectral library-based identification and the quantitative analysis of polar contact pesticide residues on food.

Growth, metabolism and digestibility of Nile tilapia fed diets with solvent and extrusion-treated Jatropha curcas cake

Physic nut Jatropha curcas cake/meal obtained after oil extraction has a high protein content, however, the presence of antinutrients (trypsin inhibitor, lectin and phytate) and toxic compounds (phorbol esters) limit their use as an alternative feedstuff. Thus, the detoxification process in cake/meal is necessary to allow their inclusion in fish diets. The present study aimed to evaluate the effects of solvent and extrusion-treated jatropha cake (SETJC) in Nile tilapia (Oreochromis niloticus) diets on growth, body composition, nutrient utilization, metabolic and hematological responses, and digestibility of experimental diets. Five experimental diets were formulated to be isonitrogenous (28.50% digestible protein) and isoenergetic (13.39 MJ/kg digestible energy) with graded levels of SETJC (0, 3, 6, 9, and 12%). The experimental design was completely randomized with five treatments and four replicates. The detoxification treatments reduced the phorbol esters (PE) of jatropha cake by 96% (0.58 mg/g of PE before and 0.023 mg/g of PE after treatments). Increased levels of SETJC depressed growth, feed efficiency, and protein digestibility. A similar trend was observed for hematological and biochemistry parameters. Aspartate and alanine aminotransferase, as well as phosphorus and magnesium concentrations in the fillets, increased at the highest levels of SETJC. Thus, the data of the present study suggests that the residual content, different structural forms of phorbol ester and its biological activity, as well as some antinutritional factors, can influence negatively the growth, metabolism and digestibility of experimental diets for Nile tilapia.

A modified micro-solid phase extraction device for in-port elution and injection into portable liquid chromatography: A proof-of-concept study

A micro-solid phase extraction (micro-SPE) device packed with a C18 sorbent (10 mg) has been developed for the enrichment and purification of organic water pollutants prior to their analysis using a portable liquid chromatograph with a dual UV detector. To this end, the sorbent was immobilized at the inlet of a 4 mm syringe filter (0.20 µm), which was modified to reduce its internal volume. The filter was coupled to the needle of the chromatograph. After loading the sample and cleaning the sorbent for analyte purification, the device was installed into the injection port of the chromatograph, and the target compounds were desorbed and transferred directly to the chromatographic column with a small volume of organic solvent. Under optimized conditions, sample volumes as large as 50 mL could be processed with the micro-SPE device, while the analytes were desorbed with only 60 µL of methanol. As a result, efficient preconcentration could be reached, as demonstrated for different water contaminants, namely aclonifen, bifenox, tritosulfuron, triflusulfuron-methyl and caffeine. The proposed micro-SPE device was applied to the analysis of different types of water (river, well, sea, ditch and wastewater). The recoveries of the target compounds in samples ranged from 76 % to 109 %, which allowed their detection at low to sub µg/L levels. All operations were carried out manually, and thus, no additional laboratory instruments such as centrifuges, stirrers or evaporators were required. This proof-of-concept study shows that the proposed micro-SPE approach can be considered a reliable and effective option for the on-site analysis of pollutants in environmental water samples by portable liquid chromatography.

An Environmental-friendly Procedure Based on Deep Eutectic Solvent for Extraction and Determination of Toxic Elements in Fish Species from Different Regions of Iraq

In this study, an eco-friendly procedure was established by vortex-assisted liquid-phase microextraction based on deep eutectic solvent (VA-LPME-DES) combined with graphite furnace atomic absorption spectroscopy (GFAAS). The performance of this method was demonstrated by the extraction and analysis of lead (Pb), cadmium (Cd), and mercury (Hg) in fish samples. The hydrophobic DES is considered as a green extractant (environmentally friendly and less toxic than common organic solvents) and is a suitable alternative to common toxic organic solvents and is made of l-menthol and ethylene glycol (EG) with a molar ratio of 1:1. Under optimized conditions, the method linearity was in the ranges of 0.15-150 µg kg-1 with the coefficient of determinations (r2) higher than 0.996. Accordingly, the detection limits for Pb, Cd, and Hg were 0.05, 0.05, and 0.10 µg kg-1, respectively. The analysis of fish samples showed that the concentration of toxic elements in fish caught from the Tigris and Euphrates Rivers is much higher than the concentration of these elements in locally farmed trout fish. Also, the analysis of fish-certified reference materials with presented procedure produced results that were in good agreement with the certified values. The results showed that VA-LPME-DES is a very cheap, fast, and environmental-friendly procedure for the analysis of toxic elements in different types of fish species.

Microplastics and hydrocarbons in soils: Quantification as an anthropic carbon source

The literature on the presence of microplastics (MPs) and their potential impact on terrestrial ecosystems is still scarce. Interestingly, soil MPs are detected as organic carbon (SOC) using traditional quantification methods (e.g., loss on ignition [LOI]), although its dynamics in the environment will be different. The objective of this study was to quantify the carbon (C) contribution of MPs to the SOC in superficial soil samples from a coastal urban wetland (Avellaneda, Buenos Aires, Argentina) with the features of a humid subtropical forest and compare with hydrocarbon contribution. Soil samples were split for analysis of moisture content; texture (sieve and pipet method); organic matter as a LOI (8 h at 450 °C); total hydrocarbons (THCs; gravimetry of solvent extractable matter); n-alkanes (solvent extraction and gas chromatography-flame ionization detection analysis); and extraction of MPs (floatation in NaCl_aq , filtration, H₂ O₂ digestion, and visual sorting under a stereomicroscope). The superficial soil was a sandy clay loam with a large organic matter content (19%-30%). The THC averaged 2.5 ± 1.9 g kg and the marked predominance of odd-numbered carbon n-alkanes maximizing at C29 and C31 show the contribution of the terrestrial plant waxes. The average number of MPs was 587 ± 277 items kg of dry soil, predominantly fibers. Taking account of the C content, THCs and MPs add to the soil 1.23 ± 1.10 ton C ha and 0.10-0.97 ton C ha, respectively. Therefore, in this system with humid forest characteristics, the MPs represent between 0.12% and 1.25% of soil estimated carbon, in a magnitude similar to the C contribution of THCs (0.6%-4.2%). This preliminary study shows the relevance of discriminating MPs from other carbon sources and presents a description of their impact on soils to advance future research or tools for decision-makers. Integr Environ Assess Manag 2023;19:698-705. © 2022 SETAC.

Chlorinated solvents source identification by nonlinear optimization method

In this work, chloride ions were used as conservative tracers and supplemented with conservative amounts of chloroethenes (PCE, TCE, Cis-DCE, 1,1-DCE), chloroethanes (1,1,1-TCA, 1,1-DCA), and the carbon isotope ratios of certain compounds, the most representative on the sites studied, which is a novelty compared to the optimization methods developed in the scientific literature so far. A location of the potential missing sources is then proposed in view of the balances of the calculated mixing fractions. A test of the influence of measurement errors on the results shows that the uncertainties in the calculation of the mixture fractions are less than 11%, indicating that the source identification method developed is a robust tool for identifying sources of chlorinated solvents in groundwater.

In vitro antimicrobial efficacy of Cassia alata (Linn.) leaves, stem, and root extracts against cellulitis causative agent Staphylococcus aureus

BACKGROUND

Cellulitis is a common skin disease encountered in medical emergencies in hospitals. It can be treated using a combination of antibiotics therapy; however, the causative agent Staphylococcus aureus has been reported to develop resistance towards the currently used antibiotics. Therefore, the search for more alternative herbal origin antimicrobial agents is critical.

AIM

In this study, maceration and Soxhlet extraction of the whole plant of Cassia alata Linn. (leaves, roots, and stem) were performed using four solvents with different polarities, namely n-hexane, ethyl acetate, ethanol and distilled water. The crude extracts were screened using agar well diffusion, colorimetric broth microdilution, grid culture and bacterial growth curve analysis against Staphylococcus aureus. The phytochemicals in the crude extracts were identified using Gas Chromatography-Mass Spectrometry (GC-MS).

RESULTS

Agar-well diffusion analysis revealed that extraction using ethyl acetate showed the largest inhibition zone with an average diameter of 15.30 mm (root Soxhlet extract) followed by 14.70 mm (leaf Soxhlet extract) and 13.70 mm (root maceration extract). The lowest minimum inhibitory and minimum bactericidal concentration in root Soxhlet extract using ethyl acetate was 0.313 and 0.625 µg µL^-1, respectively. Our study proved that crude extract of the plant suppressed the growth of S. aureus as evidenced from a significant regression extension (p < 0.06, p = 0.00003) of lag phase for 6 h after the treatment with increased concentration. Based on the GC-MS analysis, 88 phytochemicals consist of fatty acids, esters, alkanes, phenols, fatty alcohols, sesquiterpenoids and macrocycle that possibly contributed to the antimicrobial properties were identified, 32 of which were previously characterized for their antimicrobial, antioxidant, and anti-inflammatory activities.

CONCLUSION

Ethyl acetate crude extract was better than the other investigated solvents. The root and stem of C. alata showed significant antimicrobial efficacy against S. aureus in this study. The remaining 56 out of 88 phytochemicals of the plant should be intensively studied for more medicinal uses.

Efficiency of Different Solvents in the Extraction of Bioactive Compounds from Plinia cauliflora and Syzygium cumini Fruits as Evaluated by Paper Spray Mass Spectrometry

Jabuticaba (Plinia cauliflora) and jambolan (Syzygium cumini) fruits are rich in phenolic compounds with antioxidant properties, mostly concentrated in the peel, pulp, and seeds. Among the techniques for identifying these constituents, paper spray mass spectrometry (PS-MS) stands out as a method of ambient ionization of samples for the direct analysis of raw materials. This study aimed to determine the chemical profiles of the peel, pulp, and seeds of jabuticaba and jambolan fruits, as well as to assess the efficiency of using different solvents (water and methanol) in obtaining metabolite fingerprints of different parts of the fruits. Overall, 63 compounds were tentatively identified in the aqueous and methanolic extracts of jabuticaba and jambolan, 28 being in the positive ionization mode and 35 in the negative ionization mode. Flavonoids (40%), followed by benzoic acid derivatives (13%), fatty acids (13%), carotenoids (6%), phenylpropanoids (6%), and tannins (5%) were the groups of substances found in greater numbers, producing different fingerprints according to the parts of the fruit and the different extracting solvents used. Therefore, compounds present in jabuticaba and jambolan reinforce the nutritional and bioactive potential attributed to these fruits, due to the potentially positive effects performed by these metabolites in human health and nutrition.

Characteristics and source origin analysis of halogenated hydrocarbons in Hong Kong

Despite being regulated globally for almost three decades, halocarbon continues to play a vital role in climate change and ozone layer because of its long lifetime in the ambient air. In recent years, unexpected halocarbon emissions have been found in Asia, raising concerns about ozone recovery. As a number of studies focused on halocarbon variations and source profiles, there is an increasing need to identify halocarbon source origins. In this study, an eight-month regular air sampling was conducted at a coastal site in Hong Kong from November 2020 to June 2021, and seventeen halocarbon species were selected for extensive investigation after advanced sample analysis in our laboratory. The temporal variations of halocarbon mixing ratio enhancements were analyzed, and the spatial variations of source origins were investigated by wind sectors and backward trajectory statistics. Our results indicate lower enhancements beyond the background values for major regulated CFCs and CCl₄ than later controlled HCFCs and HFCs, suggesting the greater progress of Montreal Protocol implementation for the former species. The notable high enhancement values of non-regulated halocarbons from the north direction indicate their widespread usage in China. The source apportionment analysis estimates the contributions from six emission sectors on measured halocarbons, including solvent usage (43.57 ± 4.08 %), refrigerant residues (17.05 ± 5.71 %), cleaning agent/chemical production (13.18 ± 4.76 %), refrigerant replacements (13.06 ± 2.13 %), solvent residues (8.65 ± 3.28 %), and foaming agent (4.49 ± 1.08 %). Trajectories statistical analysis suggests that industrial solvent was mainly contributed by eastern China (i.e., Shandong and YRD), cleaning agent/chemical production was spread over southeast China (i.e., YRD and Fujian), and refrigeration replacements were dominant in Hong Kong surrounding regions. This work provides insight into the progress made in implementing the Montreal Protocol in Hong Kong and the surrounding region and the importance of continuous emission control.

Simultaneous determination of benzothiazoles, benzotriazoles, and benzotriazole UV absorbers by solid-phase extraction-gas chromatography-mass spectrometry

Benzotriazoles (BTRs), benzothiazoles (BTHs), and benzotriazole ultraviolet absorbers (BUVs) are common products in plastic rubber and personal care products. Due to their toxicity and bioaccumulation, they have been identified as emerging contaminants (ECs) in the environment. Solid-phase microextraction (SPME) and solid-phase extraction (SPE) combined with gas chromatography-mass spectrometry (GC-MS) were used for the enrichment and detection of the contaminants in seawater and sediment, respectively. The conditions of SPE and SPME were optimized in terms of material, temperature, time, pH, ionic strength, extraction solvent, and elution solvent. Although SPME requires a small sample volume, it is not reliable for the extraction efficiency and reproducibility of BTHs, BTRs, and BUVs in seawater. However, the precision of SPE-GC-MS for the determination of BTHs, BTRs, and BUVs was around 10%, with recoveries of 67.40-102.3% and 77.35-101.8% in seawater and sediment, respectively. The limits of detection of 14 contaminants in seawater and sediment were 0.03-0.47 ng/L and 0.01-0.58 ng/g, respectively. Secondly, BTHs, BTRs, and BUVs were detected with low ecological risk when SPE-GC-MS was applied to the analysis of seawater and sediment samples from the Yangtze estuary and its adjacent areas. The SPE-GC-MS was highly precise with lower detection limits relative to previous studies and thus was able to meet the requirements for the detection of BTHs, BTRs, and BUVs in seawater and sediments.

Porous agarose/chitosan/graphene oxide composite coupled with deep eutectic solvent for thin film microextraction of chlorophenols

In this project, a three-dimensional graphene oxide coated agarose/chitosan (ACGO) porous film was synthesized and utilized as sorbent in thin film microextraction (TFME) technique to extract 4-chlorophenol, 2,4-dichlorophenol, 3,5-dichlorophenol and 2,4,6-trichlorophenol as the model analytes in various real samples such as agricultural waste water, honey and tea samples. In addition, deep eutectic solvent made of tetra ethyl ammonium chloride/chlorine chloride was used as a desorption solvent. The effect of various variables, such as: extraction time, stirring rate, solvent desorption volume, desorption time, ionic strength and solution pH on the extraction efficiency of the method was studied and optimized. Under the optimized condition, the linear range of the method was obtained in the range of 0.1-500μgL^-1 for testing analytes (4-chloropheol=0.1-500μgL^-1, 2,4-dichlorophenol=0.2-500μgL^-1, 3,5-dichlorophenol=0.5-500μgL^-1 and 2,4,6-trichlorophenol=0.2-500μgL^-1). The obtained correlation coefficients (r²) were between 0.9984 and 0.9994. The limits of detection (LODs) were also calculated between 0.03 - 0.13μgL^-1. The relative standard deviations (RSDs%) were obtained in the range of 2.8 to 5.9%. The enrichment factor (EFs) values for the studied analytes were also obtained in the range of 33.4-35.8. In addition, the obtained results indicated that the prepared film can potentially be used for more applications in the field of environment, food safety, and drug analysis.

Enhanced Physicochemical Stability of the L-DOPA Extract of Mucuna pruriens Seeds by Adding Phyllanthus emblica

Levodopa (L-DOPA) is an essential drug for the treatment of Parkinson's disease. Currently, L-DOPA can be produced by chemical synthesis and can also be found naturally in many herbs, especially Mucuna Pruriens (MP). According to clinical research, the MP extract containing L-DOPA for the treatment of Parkinson's disease could reduce side effects more than the synthetic one. Unfortunately, MP extracts can be easily degraded. Changes in physical and chemical properties such as the appearance (color, melt, solid lump) and the reduction of L-DOPA content in the extract were commonly observed. Therefore, it is necessary to develop an extraction procedure to stabilize the extract of L-DOPA. This study attempted to enhance the extraction process by modifying the traditional acidification approach using hydrochloric acid, citric acid, or ascorbic acid. According to the stability test results, using Phyllanthus emblica water (PEW) as a solvent improved the preservative properties more than other solvents. The color of the PEW-MP powder changed slightly after 12 months of accelerated storage, but the amount of L-DOPA remained the highest (73.55%). Moreover, L-DOPA was only detected in MP and PEW-MP, but not PEW alone (the HPTLC chromatogram at Rf 0.48 and the HPLC chromatogram at Rt 6.0 min). The chemical profiles of PEW and L-DOPA observed in the chromatograms indicated that they are independently separated. As a result, they can be applied to a quality control process. Therefore, PEW was proven to be a powerful solvent for L-DOPA herbal extract that could be readily used as a raw material for herbal products.

Estimating evaporation rates and contaminant air concentrations due to small spills of non-ideal aqueous organic solvent mixtures in a controlled environment

Although small spills of non-ideal organic solvent mixtures are ubiquitous undesirable events in occupational settings, the potential risk of exposure associated with such scenarios remains insufficiently investigated. This study aimed to examine the impact of non-ideality on evaporation rates and contaminant air concentrations resulting from small spills of organic solvent mixtures. Evaporation rate constants alphas (α) were experimentally measured for five pure solvents using a gravimetric approach during solvent evaporation tests designed to simulate small spills of solvents. Two equations were used for estimating contaminants' evaporation rates from aqueous mixtures assuming either ideal or non-ideal behavior based on the pure-chemical alpha values. A spill model also known as the well-mixed room model with exponentially decreasing emission rate was used to predict air concentrations during various spill scenarios based on the two sets of estimated evaporation rates. Model predictive performance was evaluated by comparing the estimates against real-time concentrations measured for the same scenarios. Evaluations for 12 binary non-ideal aqueous mixtures found that the estimated evaporation rates accounting for the correction by the activity coefficients of the solvents (median = 0.0318 min^-1) were higher than the evaporation rates estimated without the correction factor (median = 0.00632 min^-1). Model estimates using the corrected evaporation rates reasonably agreed with the measured values, with a median predicted peak concentrations-to-measured peak concentrations ratio of 0.92 (0.81 to 1.32) and a median difference between the predicted and the measured peak times of -5 min. By contrast, when the non-corrected evaporation rates were used, the median predicted peak concentrations-to-measured peak concentrations ratio was 0.31 (0.08 to 0.75) and the median difference between the predicted and the measured peak times was +33 min. Results from this study demonstrate the importance of considering the non-ideality effect for accurately estimating evaporation rates and contaminant air concentrations generated by solvent mixtures. Moreover, this study is a step further in improving knowledge of modeling exposures related to small spills of organic solvent mixtures.

Characteristics and sources of ambient Volatile Organic Compounds (VOCs) at a regional background site, YRD region, China: Significant influence of solvent evaporation during hot months

Continuous measurement of 98 volatile organic compounds (VOCs) was conducted during 2017-2019 at a regional background site (Shanxi) located at northeast of Zhejiang Province, YRD region, China. The average concentration of total VOCs (TVOCs) was 25.4 ± 18.4 ppbv, and an increasing trend (+12.2 %) was observed. Alkanes were the most abundant VOC group among all seasons, accounting for 43.5 % of TVOCs. Oxygenated VOCs (OVOCs), aromatics, halides and alkenes contributed 15.9 %, 15.7 %, 11.7 % and 10.3 % of TVOCs concentration, respectively. Biogenic VOCs (BVOCs) and OVOCs showed distinguished diurnal cycle from primary anthropogenic VOCs. Photochemical reactivity analysis based on ozone formation potential (OFP) and OH loss rate (L^OH) indicated that aromatics and alkenes were the most significant contributor, respectively. Toluene, xylene (m/p- and o-), ethene and propene were the largest contributor of annual OFP, with the mean OFP being 33.8 ± 44.3 μg·m^-3, 31.9 ± 32.1 μg·m^-3, 9.29 ± 11.4 μg·m^-3, 22.1 ± 21.3 μg·m^-3 and 12.8 ± 19.5 μg·m^-3, respectively. Seven sources were identified with positive matrix factorization (PMF): petrochemical industry (13.8 %), biogenic emission (1.0 %), solvent usage-toluene (16.9 %), vehicular exhaust (43.8 %), Integrated circuits industry (3.8 %), solvent usage-C8 aromatics (10.9 %), and gasoline evaporation (9.8 %). Vehicular exhaust was the most significant source (43.8 %) during the whole measurement period. Solvent usage, petrochemical industry, and gasoline evaporation showed high temperature dependency. The integrated contribution of solvent usage and industrial processes were higher than vehicular exhaust during hot months. These sources also have higher chemical reactivities and can contribute more on O₃ formation. Our results are helpful on determining the control strategies aiming at alleviating O₃ pollution.

Characterization of Key Odorants in Chardonnay Seeds

Chardonnay marc, a co-product of the winemaking industry, is a combination of skins, seeds, and stems remaining after the juice is pressed from the grapes. This co-product amounts to over half a million tons per year. Recently, Chardonnay marc has been emerging as a healthy and flavorful food ingredient. The aroma contribution of the seeds to the overall aroma of Chardonnay marc remains unknown. In the present study, 43 odorants were identified in Chardonnay seeds employing aroma extract dilution analysis (AEDA) performed on a distillate prepared by solvent extraction and solvent-assisted flavor evaporation (SAFE) distillation. Of those, 6 odorants with a flavor dilution (FD) factor ≥64 were quantitated using stable isotope dilution assays (SIDAs). The odorants included (2E,4E)-deca-2,4-dienal (fatty, OAV 8028), 3-methylnonane-2,4-dione (hay, OAV 4772), (2E,4E)-nona-2,4-dienal (fatty, OAV 1750), hexanal (green, OAV 1481), linalool (floral, citrus, OAV 28), and 2-phenylethanol (floral, rose, OAV 2). An aroma simulation model was prepared based on the quantitative data, and its aroma was a close match to the Chardonnay seed powder. Omission studies applied to the aroma simulation model showed that hexanal and 3-methylnonane-2,4-dione were the key odorants driving the aroma profile. This research established a foundation for future studies aimed at optimizing the flavor of Chardonnay marc powder.

Comprehensive non-target screening of biomagnifying organic contaminants in the Baltic Sea food web

High-resolution mass spectrometry (HRMS) based non-target screening (NTS) is a powerful approach for the simultaneous determination of multiple environmental contaminant classes in complex biota samples. In this study, trophic biomagnification factor (TMF) directed NTS was performed to find and (tentatively) identify known, emerging, and new chemical contaminants that are persistent and biomagnify in Baltic Sea biota. The investigated food web included seven species: one filter feeder (blue mussel, Mytilus edulis), two fish (eelpout, Zoarces viviparous; herring, Clupea harengus), two marine mammals (harbor porpoise, Phocoena phocoena; grey seal, Halichoerus grypus) and two birds (guillemot, Uria aalge; white-tailed sea eagle, Haliaeetus albicilla). The NTS procedure included extraction with organic solvent mixtures, two-step high-resolution gel permeation chromatography clean-up, Florisil® fractionation, gas chromatography (GC) HRMS analysis in electron ionization (EI) and electron capture negative ion chemical ionization (ECNI) modes, and NTS data processing. The latter was performed differently for the EI and ECNI data: the EI data were treated using a flexible and highly automated TMF-directed NTS workflow, whereas the ECNI data were treated with a simpler and less automated workflow that specifically screened for brominated compounds. The two workflows collectively revealed biomagnification (statistically significant TMF values) of >250 tentatively identified compounds, including legacy persistent organic pollutants (POPs), such as PCBs and PCB-related compounds, DDT and its metabolites, and organochlorine pesticides (OCPs), contaminants of emerging concern (CECs), and halogenated natural products (HNPs). Among the tentatively identified CECs, nine have not previously been reported in environmental biota samples. These included four polymer additives (used as antioxidants, rubber additives or plasticizers) and two cosmetic product additives (ethyl myristate and isopropyl palmitate). The CECs should be prioritized for future structure verification and quantification using reference standards.

Heavy metal and phthalate contamination and labeling integrity in a large sample of US commercially available cannabidiol (CBD) products

BACKGROUND

The demand and availability of commercially available cannabidiol (CBD) products has grown substantially, which is of particular interest among medically vulnerable people. Because the cannabis plant is recognized as a bioaccumulator, which is highly effective at absorbing and retaining contaminants (e.g., heavy metals) in soil, it is important to characterize the degree of contamination in CBD products and their label accuracy to better estimate potential health benefits and risks associated with consumption.

METHODS

Levels of lead, cadmium, arsenic, mercury, four phthalates, and CBD labeling accuracy were quantified in a selection of commercially available CBD products in the US. Heavy metal concentrations were quantified by inductively coupled plasma-mass spectrometry. Phthalates were quantified by liquid chromatography-tandem mass spectrometry. CBD labeling accuracy was determined by extracting samples into a suitable organic solvent and analyzing using liquid chromatography with diode array detection.

RESULTS

Lead was detected in 42 %, cadmium in 8 %, arsenic in 28 %, and mercury in 37 % of 121 edible CBD products. Four edible CBD products exceeded the California Proposition 65 threshold for daily lead consumption of 0.5μg in two servings. The percentage of edible products with detectable phthalate concentrations varied between 13 % and 80 % across the four phthalates, with DEHP being most prevalent. Among all products tested for CBD labeling accuracy (topicals, edibles, N = 516), 40 % contained <90 % of the CBD indicated on the product label, 18 % contained >110 %, and only 42 % of products fell within ±10 % of the CBD claimed on the manufacturer label. Concentrations of heavy metals and phthalates were not associated with CBD potency.

CONCLUSIONS

Low-level contamination of edible CBD products with heavy metals and phthalates is pervasive. There is substantial discrepancy between the product label claims for CBD potency and the amount measured in both edible and topical products, underscoring the need for tight regulations for CBD product label integrity to protect consumers.

Application of sulfur-coated magnetic carbon nanotubes for extraction of some polycyclic aromatic hydrocarbons from water resources

In the present work, novel sulfur-coated magnetic carbon nanotubes (MCNTs-S) material was fabricated by S coating on the MCNTs using a simple heating procedure. TGA, EDX, XRD, TEM, and VSM were employed to characterize the as-prepared composite. Using HPLC-UV system, the produced superparamagnetic sorbent was employed for the extraction and measurement of trace levels of five polycyclic aromatic hydrocarbons (PAHs) in environmental waters. The synergistic effect of the sulfur layer and CNTs substrate is primarily responsible for the remarkable extraction efficiency of the MCNTs-S sorbent towards PAHs. The experimental factors including MCNTs-S dosage, sorption time, elution solvent, ionic strength and solution pH were explored and optimized. Considering that the ionic strength and pH do not have any impact on the PAHs extraction, as a result, there is no need the unnecessary adjustment of the water samples. The linear dynamic ranges and detection limits under optimal conditions were in the range of 0.05-0.11 ng mL^-1 and 0.2-150 ng mL^-1, respectively. The analysis of PAHs in the real samples (sea water and river water) using this approach was successfully assessed with appropriate recovery values (94.6%-99.0%).

A review of pesticide phototransformation on the leaf surface: Models, mechanism, and influencing factors

Phototransformation is an important environmental fate of pesticides on plant leaves. This review found that the photodegradation rates of pesticides on leaves might be faster or slower than those in organic solvents or on glass because of the different spectral patterns and light fluxes on the model surface. Wax was found to play an important role in pesticide phototransformation because it has photosensitizing properties, which might be stimulated under light irradiation to produce reactive species, such as hydroxyl radicals, singlet oxygen, methyl radicals, alkyl radicals, and superoxide radicals. These reactive species could accelerate pesticide photodegradation by several times. Wax can also decrease the photodegradation rate of pesticides by quenching reactive species or light-shielding effects. The environmental conditions and phytochemical properties of leaves play important roles in pesticide phototransformation primarily because the composition of wax varies with plant species and environmental factors. The phototransformation of pesticides on leaves was promoted by a low dosage of adjuvant because they act as photosensitizers and improve the dispersity of pesticides, while it was inhibited at a high concentration of adjuvant because of their light shielding effect. Finally, recommendations for future research were discussed, including (1) distinguishing the direct and indirect photodegradation of pesticides; (2) developing model, molecular level visualization and analysis techniques; (3) conducting more field research; and (4) considering the effect of climate change, especially the interaction of climatic factors. This review gives a comprehensive overview of the current knowledge of pesticide phototransformation on leaves and provides suggestions for future studies.

Characterization of per- and polyfluoroalkyl substances on fire suppression system piping and optimization of removal methods

Fire suppression systems are known to be impacted with residual, entrained per- and polyfluoroalkyl substances (PFASs) because of historical use of aqueous film forming foam (AFFF) and fluoroprotein foam. Amphiphilic PFASs aggregate at liquid:solid interfaces creating a hydrophobic layer which reduces the effectiveness of water to remove PFAS from layered surfaces. When fire suppression systems are transitioned to fluorine free foam (F3) without appropriate cleaning, residual PFASs associated with the surfaces of the fire suppression system can contaminate the replacement F3. Release of residual PFASs from fire suppression systems into F3 has been documented; however, little is known about the residual PFASs associated with the surfaces of the fire suppression systems. More information is needed to develop methods to appropriately remove PFASs from fire suppression systems to prevent costly and inefficient foam transitioning and preserve the PFAS-free benefit of F3. The objective of this work was to evaluate the distribution and composition of PFASs on hangar piping exposed to PFAS-containing firefighting foam for a prolonged period. Two assessment methods were used: 1) extractions with methanol, water, and a proprietary aqueous organic solvent (Fluoro Fighter™); and 2) direct imaging methods of the surface. Extractions were analyzed with mass spectrometry and combustion ion chromatography. Results indicate pipe in contact with PFAS-containing firefighting foam can amass approximately 10 μg/cm² of surface-associated PFAS residual following decades of exposure. Fluoro Fighter demonstrated higher PFAS removal per surface area of pipe than methanol (p = 0.007) or water extraction (p < 0.0001). Scanning electron microscope (SEM) images of the hangar piping reveal deposits suspected to be self-assembled PFAS layers, as evidenced by examination of pipe surfaces using X-ray photoelectron spectroscopy (XPS), which revealed atomic fluorine on the surface of the pipe.

Characteristics and sources analysis of ambient volatile organic compounds in a typical industrial park: Implications for ozone formation in 2022 Asian Games

In this study, volatile organic compounds (VOCs) at a major industrial park in Yangtze River Delta Region, China, along with an urban site had been investigated for three years (2018-2020). The daily-mean concentration of total 97 VOCs in the industrial park (224.3 ± 139.1 μg/m³) was about twice that of urban site (112.0 ± 64.2 μg/m³). Halohydrocarbons were predominant VOCs species at both sites accounting for 39.0 % and 32.2 % in industrial and urban sites, respectively. Annual-average concentrations of total VOCs slowed down gradually in industrial park, while that of the urban site increased annually. Evident seasonal and diurnal variations were observed for VOCs concentration in both sites. Higher VOCs concentrations appeared in summer for industrial park, and high concentrations generally appeared at 8:00 and 19:00-20:00 in two sites. Diagnostic ratios of m/p-xylene to ethylbenzene indicated vehicle emissions and solvent volatilization were main sources of VOCs in industrial site during winter. Further positive matrix factorization identified fuel usage and industry source as major sources in industrial park and urban site, respectively. Ozone formation potential calculations showed aromatics contributed most to ozone formation, and benzyl chloride was a key species when its concentration was high. Further empirical kinetic modeling approach revealed ozone formation in industrial park was in VOCs-limited regime. Through air mass trajectory analysis, air pollutants especially ozone from industrial park will be transported to stadiums by northeast wind during the 2022 Asian Games. The reductions in VOCs emissions from industrials are highly recommended for ozone control in 2022 Asian Games.

Characterization of Odorants in Loomis' Mountain Mint, Pycnanthemum loomisii

Loomis' mountain mint, Pycnanthemum loomisii Nuttall, is a species of mint native to the American Southeast. In the present study, 38 odorants were identified employing aroma extract dilution analysis (AEDA) performed on a distillate prepared by solvent extraction and solvent-assisted flavor evaporation (SAFE) distillation of dried P. loomisii. Seven odorants with flavor dilution (FD) factors ≥16 were quantitated using stable isotope dilution assays (SIDA), and their odor activity values (OAV) were calculated. In addition, the stereochemical composition of chiral odorants was also determined by chiral chromatography. Odor simulation experiments demonstrated that when 1,8-cineole (eucalyptus; OAV 6400), linalool (floral, citrus; OAV 120), β-ionone (floral, violet; OAV 86), borneol (earthy; OAV 56), and eugenol (clove; OAV 2.5) were combined in their natural concentrations, the model successfully mimicked the plant's aroma. The results of this investigation provide a foundation for additional investigations into the natural variation in aroma chemistry of different selections of P. loomisii and other members of the Pycnanthemum genus.

How a winding-down oil refinery park impacts air quality nearby?

It is always difficult to compare, let alone estimate, the difference of air pollutant concentrations before and after closure of a major source because the pollutants cannot be traced or predicted after entering the ambient. Indeed, we are not aware of any studies specifically related to the air pollutants impacted by a winding-down source. In this work, we applied nine years (2010-2018) online measurement of air pollutants (including PM₁₀, PM_2.5, NO₂, SO₂, O₃ and VOCs) to investigate (i) the temporal behavior of air pollutants before and after closure of an oil refinery park by using pair-wise statistics and correlations between wind speed and direction, and (ii) the source impacts on O₃ concentrations using PMF coupled with multiple linear regression (MLR) analysis (PMF-MLR). Example applications are presented at two monitoring sites (A and B) close to the Kaohsiung Oil Refinery (KOR), located in the southern industrial city of Taiwan. The results show that the KOR shutdown changed air pollutant concentrations to a certain extent in these study areas. We also conclude that, instead of using propylene-equivalent and ozone formation potential (OFP) concentrations, it is better to estimate the formation of O₃ based on PMF-MLR analysis as developed in this study. The PMF analysis has identified various VOCs sources at both sites including solvent usage, petrochemical industrial sources, industrial emissions, vehicle-related sources, vegetation emissions and aged air-masses. Also, the MLR model shows that both the background sources and petrochemical industrial sources may significantly change O₃ concentrations.

Characterization of biochar-derived organic matter extracted with solvents of differing polarity via ultrahigh-resolution mass spectrometry

In recent years, biochar, a porous carbon-based material, has gained attention for its application prospects in contaminated soil remediation and soil improvement. Biochar-derived organic matter has a key role in influencing the migration and transformation of soil elements and pollutants. However, existing research concerning the molecular characteristics of biochar-derived organic matter is limited. Here, we used four polar solvents - dichloromethane (CH₂Cl₂), acetone (CH₃COCH₃), methanol (CH₃OH), and distilled water (H₂O) - to extract organic matter from soybean straw biochar and wheat straw biochar by accelerated solvent extraction (ASE). We characterized the extracts using Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). We found considerable differences in organic matter according to the extraction solvents; such differences were related to the polarity of the solvent, as well as intermolecular forces between the solvent and organic matter. CH₃OH extracted the most biochar-extractable organic matter components because CH₃OH can weaken or destroy oxygen bridge bonds in biochar and form hydrogen bonds with small-molecule organic compounds. CH₃OH and H₂O have strong extraction capacity for compounds containing heteroatoms. CH₂Cl₂-extractable organic matter is relatively labile and bioavailable, while CH₃OH- and H₂O-extractable organic matters are relatively stable. In addition, the binding capacity of biochar-derived organic matter for minerals and pollutants differed among fractions, in part because of differences in molecular weight, atomic O/C and H/C ratios, heteroatom distribution, and biomolecular compounds present in biochar-derived organic matter. The findings in this study help to select appropriate extractants to analyze biochar-derived organic matter for various research purposes, and provides a theoretical basis for biochar-based remediation of contaminated soil.