GC-MS and HPLC-MS analysis of bioactive pharmaceuticals and personal-care products in environmental matrices

Simultaneous determination of pesticide residues and rapid discrimination of corn production origin using ambient ionization mass spectrometry combined with machine learning

Food traceability is a critical aspect of quality control and food safety. In this study, a high-throughput analysis system with an analysis time of 13 min was developed for the detection of pesticide residues in corn, achieving low limits of detection (LODs) ranging from 0.59 to 14.38 μg/kg. Using this method, corn samples from different origins were found to contain distinct exogenous pesticide profiles and were classified into six categories. Based on these differential analytes, stoichiometric models were applied to explore spectral differences among the corn samples, while some cluster overlap was observed. Subsequently, the Random Forest (RF) model was employed to achieve excellent prediction performance with accuracies of 100 % in training and 98.1 % in external validation, indicating high accuracy in origin traceability. Therefore, this high-throughput system combined with machine learning shows great potential for the rapid detection of pesticide residues and origin identification, contributing significantly to food quality monitoring.

A machine learning framework to predict PPCP removal through various wastewater and water reuse treatment trains

The persistence of pharmaceuticals and personal care products (PPCPs) through wastewater treatment and resulting contamination of aquatic environments and drinking water is a pervasive concern, necessitating means of identifying effective treatment strategies for PPCP removal. In this study, we employed machine learning (ML) models to classify 149 PPCPs based on their chemical properties and predict their removal via wastewater and water reuse treatment trains. We evaluated two distinct clustering approaches: C1 (clustering based on the most efficient individual treatment process) and C2 (clustering based on the removal pattern of PPCPs across treatments). For this, we grouped PPCPs based on their relative abundances by comparing peak areas measured via non-target profiling using ultra-performance liquid chromatography-tandem mass spectrometry through two field-scale treatment trains. The resulting clusters were then classified using Abraham descriptors and log K ow as input to the three ML models: support vector machines (SVM), logistic regression, and random forest (RF). SVM achieved the highest accuracy, 79.1%, in predicting PPCP removal. Notably, a 58-75% overlap was observed between the ML clusters of PPCPs and the Abraham descriptor and log K ow clusters of PPCPs, indicating the potential of using Abraham descriptors and log K ow to predict the fate of PPCPs through various treatment trains. Given the myriad of PPCPs of concern, this approach can supplement information gathered from experimental testing to help optimize the design of wastewater and water reuse treatment trains for PPCP removal.

Distinct effects of dilute acid prehydrolysate inhibitors on enzymatic hydrolysis and yeast fermentation

The effects of dilute acid prehydrolysate from poplar were investigated and compared in the enzymatic hydrolysis, fermentation, and simultaneous saccharification fermentation (SSF) in this study. The improvement of enzymatic hydrolysis and fermentation with resin adsorption and surfactant addition has also been represented. A total of 16 phenolic alcohols, aldehydes, acids and 3 furan derivatives in the prehydrolysates were identified and quantified by gas chromatography/mass spectrometry (GC/MS). The degree of inhibition from the phenolic compounds (26.55%) in prehydrolysate on the enzymatic hydrolysis was much higher than carbohydrates-derived inhibitors (0.52-4.64%). Around 40% degree of inhibition was eliminated in Avicel enzymatic hydrolysis when 75% of prehydrolysates phenolic compounds were removed by resin adsorption. This showed distinguishing inhibition degrees of various prehydrolysate phenolic compounds. Inhibition of prehydrolysate on enzymatic hydrolysis was more dosage-dependent, while their suppression on the fermentation showed a more complicated mode: fermentation could be terminated by the untreated prehydrolysate, while a small number of prehydrolysate inhibitors even improved the glucose consumption and ethanol production in the fermentation. Correlated with this distinct inhibition modes of prehydrolysate, the improvement of Tween 80 addition in SSF was around 7.10% for the final ethanol yield when the glucose accumulation was promoted by 76.6%.

Riverine seasonal rainfall event tracing of organic pollution sources using fluorescence fingerprint difference spectrum

Elucidating the dynamics of dissolved organic matter (DOM) transport and transformation under seasonal rainfall events is essential for the conservation of riverine ecosystems, for mitigating the effects of climate change, and for crafting informed water management strategies. Therefore, this study aimed to investigate the evolutionary characteristics of organic pollution sources during consecutive rainfall events in early spring and to quantify their relative contributions to the process of surface water pollution. The results showed seasonal rainfall induces water quality exceedances in rivers due to the combined impacts of terrestrial inputs and endogenous releases. Humic acid (HA) (region V) and fulvic acid (FA) (region III) emerged as the predominant organic matter in the water column, with their fluorescence intensity altering as rainwater flushed the riverbed. Sources of pollution include agricultural and urban domestic sources (AS + DS) (72.29 %), industrial and urban domestic and microbial sources (IS + DS + MS) (37.71 %), and agricultural and industrial sources (AS + IS) (63.32 %), indicating that agricultural surface pollution discharges contribute significantly. The gas-chromatography-mass spectrometry (GC-MS) further confirmed that exogenous inputs were predominantly comprised of particulate pollutants. This study underscores the efficacy of fluorescence difference spectrometry in delineating the migration and transformation of river pollution sources during seasonal rainfall and facilitating the implementation of targeted management strategies for river ecosystems.

Analytical Methods for the Determination of Pharmaceuticals and Personal Care Products in Solid and Liquid Environmental Matrices: A Review

Among the various compounds regarded as emerging contaminants (ECs), pharmaceuticals and personal care products (PPCPs) are of particular concern. Their continuous release into the environment has a negative global impact on human life. This review summarizes the sources, occurrence, persistence, consequences of exposure, and toxicity of PPCPs, and evaluates the various analytical methods used in the identification and quantification of PPCPs in a variety of solid and liquid environmental matrices. The current techniques of choice for the analysis of PPCPs are state-of-the-art liquid chromatography coupled to mass spectrometry (LC-MS) or tandem mass spectrometry (LC-MS2). However, the complexity of the environmental matrices and the trace levels of micropollutants necessitate the use of advanced sample treatments before these instrumental analyses. Solid-phase extraction (SPE) with different sorbents is now the predominant method used for the extraction of PPCPs from environmental samples. This review also addresses the ongoing analytical method challenges, including sample clean-up and matrix effects, focusing on the occurrence, sample preparation, and analytical methods presently available for the determination of environmental residues of PPCPs. Continuous development of innovative analytical methods is essential for overcoming existing limitations and ensuring the consistency and diversity of analytical methods used in investigations of environmental multi-class compounds.

Precision fermentation with mass spectrometry-based spent media analysis

Optimization and monitoring of bioprocesses requires the measurement of several process parameters and quality attributes. Mass spectrometry (MS)-based techniques such as those coupled to gas chromatography (GCMS) and liquid Chromatography (LCMS) enable the simultaneous measurement of hundreds of metabolites with high sensitivity. When applied to spent media, such metabolome analysis can help determine the sequence of substrate uptake and metabolite secretion, consequently facilitating better design of initial media and feeding strategy. Furthermore, the analysis of metabolite diversity and abundance from spent media will aid the determination of metabolic phases of the culture and the identification of metabolites as surrogate markers for product titer and quality. This review covers the recent advances in metabolomics analysis applied to the development and monitoring of bioprocesses. In this regard, we recommend a stepwise workflow and guidelines that a bioprocesses engineer can adopt to develop and optimize a fermentation process using spent media analysis. Finally, we show examples of how the use of MS can revolutionize the design and monitoring of bioprocesses.

Simultaneous detection of pesticides and pharmaceuticals in three types of bio-based fertilizers by an improved QuEChERS method coupled with UHPLC-q-ToF-MS/MS

Bio-based fertilizers (BBFs) have the potential to contain both pesticides and pharmaceutical residues, which may pose a threat to soils, crops, and human health. However, no analytical screening method is available currently to simultaneously analyze a wide range of contaminants in the complex origin-dependent matrices of BBFs. To fill this gap, our study tested and improved an original QuEChERS method (OQM) for simultaneously analyzing 78 pesticides and 18 pharmaceuticals in BBFs of animal, plant, and ashed sewage sludge origin. In spiked recovery experiments, 34-58 pharmaceuticals and pesticides were well recovered (recovery of 70-120%) via OQM at spiking concentrations levels of 10 ng/g and 50 ng/g in these three different types of BBFs. To improve the extraction efficiency further, ultrasonication and end-over-end rotation were added based on OQM, resulting in the improved QuEChERS method (IQM) that could recover 57-79 pesticides and pharmaceuticals, in the range of 70-120%. The detection limits of this method were of 0.16-4.32/0.48-12.97 ng/g, 0.03-11.02/0.10-33.06 ng/g, and 0.06-5.18/0.18-15.54 ng/g for animal, plant, and ash-based BBF, respectively. Finally, the IQM was employed to screen 15 BBF samples of various origins. 15 BBFs contained at least one pesticide or pharmaceutical with ibuprofen being frequently detected in at concentration levels of 4.1-181 ng/g. No compounds were detected in ash-based BBFs.

Enrichment and analysis methods for trace dissolved organic carbon in reverse osmosis effluent: A review

Reverse osmosis (RO) is an essential unit for producing high-quality ultrapure water. The increasingly severe water shortage and water quality deterioration result in reclaimed water as an alternative source for ultrapure water production. However, when using reclaimed water as water sources, the dissolved organic carbon (DOC) in RO permeate exhibits higher concentration and more sophisticated components than when using clean water sources, thus affecting the effluent quality of ultrapure water and the effectiveness of subsequent treatment processes. To optimize the treatment processes, it is crucial to analyze the components of DOC. This review summarizes the enrichment and analysis methods of trace organic matter, and provides recommendations for the analysis and characterization of DOC in RO permeate. The study summarizes the operating conditions and enrichment properties of different enrichment methods, including solid-phase extraction, liquid-liquid extraction, purge-and-trap, lyophilization and rotary evaporation for low-concentration organic compounds, compares the applicability and limitations of different enrichment methods, and proposes the principles for the selection of enrichment methods. In this review, we discuss the application of mass spectrometry (including Fourier transform ion cyclotron resonance mass spectrometry) in the analysis of DOC components, and focus on data processing as the key procedure in analysis of DOC in RO permeate. Despite the advantages of mass spectrometry, an applicable workflow and open-source database are required to improve the reliability of the analysis. The treatability properties of DOC are suggested to be determined by analyzing the component characteristics or in combination with common removal techniques. This study provides theoretical support for a comprehensive analysis of DOC in RO permeates to improve the removal effect.

Efficient determination of non-steroidal anti-inflammatory drugs by micellar electrokinetic chromatography in wastewater

Recently, non-steroidal anti-inflammatory drugs (NSAIDs) have been increasingly used in humans and animals. Despite being effective against a wide variety of diseases, they pose a threat to aquatic environments. In the current work, a highly efficient, selective, and sensitive micellar electrokinetic chromatography (MEKC) method was developed for the determination of five NSAIDs in environmental water samples. The optimal separation BGE was 15 mM borate buffer (pH 9), 90 mM SDS, and 10% methanol at a separation voltage of 15 kV and a hydrodynamic injection of 10 mbar for 5 s. The results presented in this study provide a higher number of theoretical plates N > 780 000 with excellent RSDs of 0.1-1.5% and great sensitivity (3-15 μg L^-1) for NSAIDs. To validate this method, the solid phase extraction method was optimized using two different cartridges (C18 and Oasis HLB); the results showed excellent recoveries (73-111.6%) for all the analytes in wastewater samples.

Montmorillonite-based polymethacrylate composite monoliths as stationary phase materials for food and pharmaceutical analysis in capillary liquid and gas chromatography

This work relates to the preparation of novel and promising stationary phases containing inorganic-organic composites for capillary liquid and gas chromatography. A naturally occurring montmorillonite was introduced to polymethacrylate monoliths, then used under different conditions of GC and HPLC at the same time. The performance of the columns was evaluated for the separation of alkane and alkylbenzene series in GC and capillary HPLC, respectively. While the bare monoliths failed to separate the model analytes, montmorillonite-based polymethacrylate allowed a full separation of the mixtures with R_s≥1.42. The columns were applied for the determination of myrcene and limonene isomers in the peel extracts of some fruits using GC, and for the analysis of active ingredients including aspirin, vitamin-C, caffeine, and ibuprofen extracted from common drugs using capillary HPLC. In GC, fast separation was achieved in 1.0 min with R_s of 6.53. The columns exhibited the best efficiency for myrcene with 20,900 plates/m. Using the capillary HPLC columns, the active ingredients were resolved in 10 min with R_s≥5.72. The efficiency values located between 12,800-21,700 plates/m in all cases. The developed methods were found to be linear in the range of 0.10-10.0 and 0.20-180 μg/mL for GC and HPLC, respectively. In comparison with commercial columns, the results in GC methods reveal that, despite their much shorter length, the prepared columns proved a faster separation with higher efficiency and comparable detection limits and chromatographic resolution. The prepared HPLC capillaries exposed lower run times and detection limits with comparable efficiency and resolution, and consume fewer samples and mobile phase solvents. The results demonstrate that the montmorillonite-based polymethacrylate composites are applicable as stationary phases for routine analysis and quality control of important fields such as food and pharmaceutical samples.

Naturally Occurring Montmorillonite-Based Polymer Monolith Composites as Stationary Phases for Capillary Liquid and Gas Chromatography

This work is associated with the preparation of capillary chromatographic columns containing inorganic-organic composites comprised of naturally occurring montmorillonite (MMT) clay mineral and polymethacrylate monolithic material. The prepared composites combine the best qualities of both constituents, offering desirable properties for use under the disparate conditions of both GC and HPLC at the same time. The stationary phases were investigated by scanning electron microscopy (SEM), the specific surface area, and thermogravimetric analysis (TGA) and examined in terms of various conditions utilized for GC and HPLC methods. The prepared columns demonstrated an excellent permeability and stability against common chromatographic conditions, such as the eluent type, flow rate, pressure, and temperature. The results confirmed that the addition of small amounts of MMT into the monolith induced significant improvement in the specific surface area, which contributed to the formation of more active sites and enhanced the retention of analytes. The registered column backpressures did not exceed 980 kPa and 16,500 kPa for the prepared GC and HPLC columns, respectively. The prepared columns were subjected to the separation of various interesting compounds possessing different chemistries and polarities, including alkanes, alkylbenzenes, polycyclic aromatic hydrocarbons (PAHs), alcohols, ketones, phenols, some common organic solvents, and isomeric mixtures. Under the optimal conditions, the efficiency of the columns fell between 4900–38,500 plates m−1 for GC and 3400–58,800 plates m−1 for capillary HPLC applications. In all cases, the measured chromatographic resolution was more than 1.38, with excellent an peak symmetry and low tailing factors. In comparison with the most commonly used commercial columns, the polysiloxane open tubular column for GC and silica-based C18 packed column for HPLC, the prepared GC columns demonstrated a faster separation with a higher efficiency, comparable resolution and tailing factors, and lower consumption of carrier gas. Regarding the capillary columns prepared for HPLC, the chromatographic experiments exposed a much lower run time with a comparable efficiency and resolution and drastically lower consumption of mobile phase solvents and samples. The results demonstrate that the MMT-based polymethacrylate monolith composites are applicable as novel and promising separation media for analyzing various mixtures of interest in different fields, such as petrochemical and environmental samples.

Highly porous gold supraparticles as surface-enhanced Raman spectroscopy (SERS) substrates for sensitive detection of environmental contaminants

Surface-enhanced Raman spectroscopy (SERS) has great potential as an analytical technique for environmental analyses. In this study, we fabricated highly porous gold (Au) supraparticles (i.e., ∼100 μm diameter agglomerates of primary nano-sized particles) and evaluated their applicability as SERS substrates for the sensitive detection of environmental contaminants. Facile supraparticle fabrication was achieved by evaporating a droplet containing an Au and polystyrene (PS) nanoparticle mixture on a superamphiphobic nanofilament substrate. Porous Au supraparticles were obtained through the removal of the PS phase by calcination at 500 °C. The porosity of the Au supraparticles was readily adjusted by varying the volumetric ratios of Au and PS nanoparticles. Six environmental contaminants (malachite green isothiocyanate, rhodamine B, benzenethiol, atrazine, adenine, and gene segment) were successfully adsorbed to the porous Au supraparticles, and their distinct SERS spectra were obtained. The observed linear dependence of the characteristic Raman peak intensity for each environmental contaminant on its aqueous concentration reveals the quantitative SERS detection capability by porous Au supraparticles. The limit of detection (LOD) for the six environmental contaminants ranged from ∼10 nM to ∼10 μM, which depends on analyte affinity to the porous Au supraparticles and analyte intrinsic Raman cross-sections. The porous Au supraparticles enabled multiplex SERS detection and maintained comparable SERS detection sensitivity in wastewater influent. Overall, we envision that the Au supraparticles can potentially serve as practical and sensitive SERS devices for environmental analysis applications.

Effect of aluminum leaching pretreatment on catalytic pyrolysis of metallised food packaging plastics and its linear and nonlinear kinetic behaviour

This research aims to study the effect of aluminum (Al) leaching pre-treatment on the catalytic pyrolysis of metallised food packaging plastics waste (MFPW). The experiments started with removal of Al from MFPW using leaching process to prepare Al-free mixed plastic waste (MPW). The catalytic pyrolysis of MPW over ZSM-5 zeolite catalyst was carried out using thermogravimetric (TG) analysis coupled with FTIR, while GC-MS was used to observe the compounds of the volatile products. The catalytic pyrolysis kinetic behaviour of MPW was studied using the linear and nonlinear isoconversional approaches. The elemental and proximate results showed that MPW is very rich in carbon elements (79 %) and volatile content (99 %). The TG results showed that MPW and ZSM/MPW were fully decomposed in the range of 376-496 °C without any presence of char. Based on TG-FTIR analysis, methane and carboxylic acid residue were the main groups of the synthesized volatile products, whereas nitrous oxide, 1-Butanol, 1-Propene, acetic acid, and formic acid were the major GC compounds. In case of ZSM/MPW, carbon dioxide and acetic acid were the major GC compounds at 5-25 °C/min, triphenylphosphine oxide and Phosphine oxide at 30 °C/min. The kinetic analysis showed that when the activation energies are located in the range 287-297 kJ/mol (MPW) and 153-187 kJ/mol (ZSM/MPW) and KAS, Vyazovkin, and Cai methods are the most suitable models to study pyrolysis kinetic of MPW with R² > 89. Based on that, leaching and catalytic pyrolysis processes are a highly suggested technology that can be used to convert MFPW into high-added energy and chemical products.

Rapid determination of NSAIDs by capillary and microchip electrophoresis with capacitively coupled contactless conductivity detection in wastewater

A simple, rapid method using CE and microchip electrophoresis with C4 D has been developed for the separation of four nonsteroidal anti-inflammatory drugs (NSAIDs) in the environmental sample. The investigated compounds were ibuprofen (IB), ketoprofen (KET), acetylsalicylic acid (ASA), and diclofenac sodium (DIC). In the present study, we applied for the first time microchip electrophoresis with C4 D detection to the separation and detection of ASA, IB, DIC, and KET in the wastewater matrix. Under optimum conditions, the four NSAIDs compounds could be well separated in less than 1 min in a BGE composed of 20 mM His/15 mM Tris, pH 8.6, 2 mM hydroxypropyl-beta-cyclodextrin, and 10% methanol (v/v) at a separation voltage of 1000-1200 V. The proposed method showed excellent repeatability, good sensitivity (LODs ranging between 0.156 and 0.6 mg/L), low cost, high sample throughputs, portable instrumentation for mobile deployment, and extremely lower reagent and sample consumption. The developed method was applied to the analysis of pharmaceuticals in wastewater samples with satisfactory recoveries ranging from 62.5% to 118%.

Removal of Amoxicillin from Aqueous Media by Fenton-like Sonolysis/H2O2 Process Using Zero-Valent Iron Nanoparticles

High concentrations of antibiotics have been identified in aqueous media, which has diminished the quality of water resources. These compounds are usually highly toxic and have low biodegradability, and there have been reports about their mutagenic or carcinogenic effects. The aim of this study was to apply zero-valent iron-oxide nanoparticles in the presence of hydrogen peroxide and the sonolysis process for the removal of the amoxicillin antibiotic from aqueous media. In this study, zero-valent iron nanoparticles were prepared by an iron chloride reduction method in the presence of sodium borohydride (NaBH4), and the obtained nanoparticles were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and vibrating-sample magnetometry (VSM). Then, using a Fenton-like process, synthetic wastewater containing 100 to 500 mg/L amoxicillin antibiotic was investigated, and the effects of different parameters, such as the frequency (1 and 2 kHz), contact time (15 to 120 min), the concentration of hydrogen peroxide (0.3%, 0.5%, and 6%), the dose of zero-valent iron nanoparticles (0.05, 0.1, 0.5 g/L), and pH (3, 5, 10) were thoroughly studied. A pH of 3, hydrogen peroxide concentration of 3%, ultrasonic-wave frequency of 130 kHz, zero-valent iron nanoparticles of 0.5 g/L, and contaminant concentration of 100 mg/L were obtained as the optimal conditions of the combined US/H2O2/nZVI process. Under the optimal conditions of the combined process of zero-valent iron nanoparticles and hydrogen peroxide in the presence of ultrasonic waves, a 99.7% removal efficiency of amoxicillin was achieved in 120 min. The results show that the combined US/H2O2/nZVI process could be successfully used to remove environmental contaminants, including antibiotics such as amoxicillin, with a high removal percentage.

Highly sensitive LC-MS method for stereochemical quality control of a pharmaceutical drug substance intermediate

Stereochemical quality control for pharmaceutical drug substance intermediates is a daunting task, especially considering the need to separate multiple stereoisomers simultaneously with low ppm level sensitivity. To address these challenges, we have successfully implemented chiral column screening, and developed an ultrasensitive liquid chromatography-mass spectrometry (LC-MS) method to separate four stereoisomers including the API intermediate, its enantiomer, and two other diastereomers. Parameters such as mobile phase additives, MS fragmentor, and column temperature were optimized to achieve the desired selectivity and sensitivity. The method enabled stereoisomer detection with high sensitivity (2 ppm LOD and 5 ppm LOQ), good linearity, and desired spike recovery, and it has been successfully applied for stereoisomer quantitation in multiple large-scale batches and demonstrated chiral quality control of the drug substance intermediate.

A state of the art overview of carbon-based composites applications for detecting and eliminating pharmaceuticals containing wastewater

The growing prevalence of new toxins in the environment continues to cause widespread concerns. Pharmaceuticals, organic pollutants, heavy metal ions, endocrine-disrupting substances, microorganisms, and others are examples of persistent organic chemicals whose effects are unknown because they have recently entered the environment and are displaying up in wastewater treatment facilities. Pharmaceutical pollutants in discharged wastewater have become a danger to animals, marine species, humans, and the environment. Although their presence in drinking water has generated significant concerns, little is known about their destiny and environmental effects. As a result, there is a rising need for selective, sensitive, quick, easy-to-handle, and low-cost early monitoring detection systems. This study aims to deliver an overview of a low-cost carbon-based composite to detect and remove pharmaceutical components from wastewater using the literature reviews and bibliometric analysis technique from 1970 to 2021 based on the web of science (WoS) database. Various pollutants in water and soil were reviewed, and different methods were introduced to detect pharmaceutical pollutants. The advantages and drawbacks of varying carbon-based materials for sensing and removing pharmaceutical wastes were also introduced. Finally, the available techniques for wastewater treatment, challenges and future perspectives on the recent progress were highlighted. The suggestions in this article will facilitate the development of novel on-site methods for removing emerging pollutants from pharmaceutical effluents and commercial enterprises.

Critical review on hazardous pollutants in water environment: Occurrence, monitoring, fate, removal technologies and risk assessment

Water is required for the existence of all living things. Water pollution has grown significantly, over the decades and now it has developed as a serious worldwide problem. The presence and persistence of Hazardous pollutants such as dyes, pharmaceuticals and personal care products, heavy metals, fertilizer and pesticides and their transformed products are the matter of serious environmental and health concerns. A variety of approaches have been tried to clean up water and maintain water quality. The type of pollutants present in the water determines the bulk of technological solutions. The main objective of this article was to review the occurrences and fate of hazardous contaminants (dyes, pharmaceuticals and personal care products, heavy metals, and pesticides) found in wastewater effluents. These effluents mingle with other streams of water and that are utilized for a variety of reasons such as irrigation and other domestic activities that is further complicating the issue. It also discussed traditional treatment approaches as well as current advances in hazardous pollutants removal employing graphite oxides, carbon nanotubes, metal organic structures, magnetic nano composites, and other innovative forms of useable materials. It also discussed the identification and quantification of harmful pollutants using various approaches, as well as current advancements. Finally, a risk assessment of hazardous pollutants in water is provided in terms of the human health and the environment. This data is anticipated to serve as a foundation for future improvements in hazardous pollutant risk assessment. Furthermore, future studies on hazardous pollutants must not only emphasize on the parent chemicals, as well as on their possible breakdown products in various media.

Cholesteric Molecular Tweezer Artificial Receptor for Rapid and Highly Selective Detection of Ag+ in Food Samples

Chiral cholesteric molecular tweezer 7a was synthesized, and its recognition properties for Ag⁺, Al³⁺, Ca²⁺ etc., were investigated by UV and fluorescence spectra. The results showed that in ethanol/Tris (1/1, v/v, pH 7.0) buffer solution, the host molecular tweezer 7a had a specific recognition ability for Ag⁺, the detection limit was up to 1 × 10⁻⁶ mol/L, and other metal ions had little effect on Ag⁺ recognition. At the same time, the naked-eye detection of Ag⁺ was realized by the light red color of the complex solution. Furthermore, the mechanism of recognition of Ag⁺ by molecular tweezer 7a was studied by a nuclear magnetic titration test and computer molecular simulation, and a rapid detection method of Ag⁺ using host molecular tweezer 7a was established. Through the determination of Ag⁺ in milk powder, quinoa and other food samples, it was proved that this novel method had a good application prospect for the detection of Ag⁺ in food.

A new RP-HPLC method as an auxiliary tool for optimization of sample preparation procedures for tracing of PPCPs of different hydrophilicities

Recently, pharmaceutical and personal care products (PPCPs) have received considerable attention because of their increasing use. Analysis of PPCPs presents a significant analytical challenge, with high-performance liquid chromatography (HPLC) in reversed-phase mode, as the most widely used analytical technique. To facilitate the optimization of the procedures that are applied in the early stages of sample preparation, a simple and fast HPLC method is proposed in this work for the separation of some PPCPs with a wide range of hydrophilicity. Two columns were evaluated (Atlantis dC18 and Discovery HS F5); as for mobile phases: a formate buffer (40 mmol L-1, pH 4) and methanol were tested in a gradient mode. The fluorinated column allowed better separation in a shorter time and better resolution for all analytes (Rs > 1). The proposed method delivered good performance for the tracing of PPCPs and is a suitable alternative to traditional C18-based HPLC methods.

Endocrine-Disrupting Compounds: An Overview on Their Occurrence in the Aquatic Environment and Human Exposure

Endocrine-disrupting compounds (EDCs) as emerging contaminants have accumulated in the aquatic environment at concentration levels that have been determined to be significant to humans and animals. Several compounds belong to this family, from natural substances (hormones such as estrone, 17-estradiol, and estriol) to synthetic chemicals, especially pesticides, pharmaceuticals, and plastic-derived compounds (phthalates, bisphenol A). In this review, we discuss recent works regarding EDC occurrence in the aquatic compartment, strengths and limitations of current analytical methods used for their detection, treatment technologies for their removal from water, and the health issues that they can trigger in humans. Nowadays, many EDCs have been identified in significant amounts in different water matrices including drinking water, thus increasing the possibility of entering the food chain. Several studies correlate human exposure to high concentrations of EDCs with serious effects such as infertility, thyroid dysfunction, early puberty, endometriosis, diabetes, and obesity. Although our intention is not to explain all disorders related to EDCs exposure, this review aims to guide future research towards a deeper knowledge of EDCs’ contamination and accumulation in water, highlighting their toxicity and exposure risks to humans.

Detection of trace amounts of insoluble pharmaceuticals in water by extraction and SERS measurements in a microfluidic flow regime

Detection of trace amounts of poorly water-soluble pharmaceuticals or related (bio)solutions represents a key challenge in environment protection and clinical diagnostics. However, this task is complicated by low concentrations of pharmaceuticals, complex sample matrices, and sophisticated sample preparative routes. In this work, we present an alternative approach on the basis of an on-line flow extraction procedure and SERS measurements performed in a microfluidic regime. The advantages of our approach were demonstrated using ibuprofen (Ibu), which is considered as a common pharmaceutical contaminant in wastewater and should be monitored in various bioliquids. The extraction of Ibu from water to the dichloromethane phase was performed with an optimized microfluidic mixer architecture. As SERS tags, lipophilic functionalized gold multibranched nanoparticles (AuMs) were added to the organic phase. After microfluidic extraction, Ibu was captured by the functionalized AuM surface and recognized by on-line SERS measurements with up to 10-8 M detection limit. The main advantages of the proposed approach can be regarded as its simplicity, lack of need for preliminary sample preparation, high reliability, the absence of sample pretreatment, and low detection limits.

Recent advances in chiral analysis for biosamples in clinical research and forensic toxicology

This article covers current methods and applications in chiral analysis from 2010 to 2020 for biosamples in clinical research and forensic toxicology. Sample preparation for aqueous and solid biological samples prior to instrumental analysis were discussed in the article. GC, HPLC, capillary electrophoresis and sub/supercritical fluid chromatography provide the efficient tools for chiral drug analysis coupled to fluorescence, UV and MS detectors. The application of chiral analysis is discussed in the article, which involves differentiation between clinical use and drug abuse, pharmacokinetic studies, pharmacology/toxicology evaluations and chiral inversion. Typical chiral analytes, including amphetamines and their analogs, anesthetics, psychotropic drugs, β-blockers and some other chiral compounds, are also reviewed.

ANN-Based Integrated Risk Ranking Approach: A Case Study of Contaminants of Emerging Concern of Fish and Seafood in Europe

Seafood, one of the most important food commodities consumed worldwide, is considered a high-quality, healthy, and safe food option. However, marine ecosystems are the ultimate destination for a large group of chemicals, including contaminants of emerging concern, and seafood consumption is a major pathway of human exposure. With growing awareness of food safety and food quality, and increased demand for information on the risk of contaminants of emerging concern, there is a need to assess food safety issues related to harmful contaminants in seafood and ensure the safety of marine food resources. In this study, the risks of emerging compounds (endocrine disruptors, brominated flame retardants, pharmaceuticals and personal care products, and toxic elements) in fish and seafood were analyzed according to their PBT (persistence, bioaccumulation, toxicity) properties as well as in terms of their concentration levels in seafood. A hazard index (HI) was estimated for each compound by applying an artificial neural network (ANN) approach known as Self-Organizing-Maps. Subsequently, an integrated risk rank (IRI) was developed considering the values of HI and the concentrations of emerging compounds in seafood species gathered from the scientific literature. Current results identified HHCB, MeHg, NP, AHTN and PBDE209 as the top five highest ranked compounds present in seafood, according to the 50th percentile (mean) of the IRI. However, this ranking slightly changed when taking into account the 99th percentile of the IRI, showing toxic elements, methylmercury and inorganic arsenic, as having the highest risk. The outcome of this study identified the priority contaminants and should help in regulatory decision-making and scientific panels to design screening programs as well as to take the appropriate safety measures.

A review of gas chromatographic techniques for identification of aqueous amine degradation products in carbonated environments

Degradation of amines is a significant issue allied to amine-based carbon dioxide (CO₂) absorption in post-combustion CO₂ capture. It becomes essential to have a detailed understanding of degradation products for advanced post-combustion CO₂ capture technology. Identification and quantification of degradation products of amines help in practicability and environmental assessment of amine-based technology. Gas, liquid, and ion chromatographic techniques are the benchmark tools for qualitative and quantitative analyses of the amines and their derivatives. Among others, gas chromatography has been more in use for this specific application, especially for the identification of degradation products of amines. This review focuses on the critical elucidation of gas chromatographic analysis and development of methods to determine the amine degradation products, highlighting preparation methods for samples and selecting columns and detectors. The choice of detector, column, sample preparation, and method development are reviewed in this manuscript, keeping in view the industry and research applications. Furthermore, obtained results on the quantitative and qualitative analyses using gas chromatography are summarized with future perspectives.

Performance indicators for a holistic evaluation of catalyst-based degradation-A case study of selected pharmaceuticals and personal care products (PPCPs)

Considerable efforts have been made to develop effective and sustainable catalysts, e.g., carbon-/biochar-based catalyst, for the decontamination of organic pollutants in water/wastewater. Most of the published studies evaluated the catalytic performance mainly upon degradation efficiency of parent compounds; however, comprehensive and field-relevant performance assessment is still in need. This review critically analysed the performance indicators for carbon-/biochar-based catalytic degradation from the perspectives of: (1) degradation of parent compounds, i.e., concentrations, kinetics, reactive oxidative species (ROS) analysis, and residual oxidant concentration; (2) formation of intermediates and by-products, i.e., intermediates analysis, evolution of inorganic ions, and total organic carbon (TOC); and (3) impact assessment of treated samples, i.e., toxicity evolution, disinfection effect, and biodegradability test. Five most frequently detected pharmaceuticals and personal care products (PPCPs) (sulfamethoxazole, carbamazepine, ibuprofen, diclofenac, and acetaminophen) were selected as a case study to articulate the performance indicators for a holistic evaluation of carbon-/biochar-based catalytic degradation. This review also encourages the development of alternative performance indicators to facilitate the rational design of catalysts in future studies.

Monitoring dissolved organic matter in wastewater and drinking water treatments using spectroscopic analysis and ultra-high resolution mass spectrometry

Dissolved organic matter (DOM) plays a critical role in determining the quality of wastewater and the safety of drinking water. This is the first review to compare two types of popular DOM monitoring techniques, including absorption spectroscopy and fluorescence excitation-emission matrices (EEMs) coupled with parallel factor analysis (PARAFAC) vs. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS), for the applications in wastewater and drinking water treatments. The optical techniques provide a series of indices for tracking the quantity and quality of chromophoric and fluorescent DOM, while FT-ICR-MS is capable of identifying thousands of DOM compounds in wastewater and drinking water at the molecule level. Both types of monitoring techniques are increasingly used in studying DOM in wastewater and drinking water treatments. They provide valuable insights into the variability of DOM composition in wastewater and drinking water. The complexity and diversity of DOM highlight the challenges for effective water treatments. Different effects of various treatment processes on DOM are also assessed, which indicates that the information on DOM composition and its removal is key to optimize the treatment processes. Considering notable progress in advanced treatment processes and novel materials for removing DOM, it is important to continuously utilize these powerful monitoring tools for assessing the responses of different DOM constituents to a series of treatment processes, which can achieve an effective removal of DOM and the quality of treated water.

Investigation of Organic Acids in Saffron Stigmas (Crocus sativus L.) Extract by Derivatization Method and Determination by GC/MS

The beneficial health properties of organic acids make them target compounds in multiple studies. This is the reason why developing a simple and sensitive determination and investigation method of organic acids is a priority. In this study, an effective method has been established for the determination of organic (lactic, glycolic, and malic) acids in saffron stigmas. N-(tert-butyldimethylsilyl)-N-methyltrifluoroacetamide (MTBSTFA) was used as a derivatization reagent in gas chromatography combined with mass spectrometric detection (GC/MS). The saffron stigmas extract was evaporated to dryness with a stream of nitrogen gas. The derivatization procedure: 0.1 g of dried extract was diluted into 0.1 mL of tetrahydrofuran, then 0.1 mL MTBSTFA was orderly and successively added into a vial. Two different techniques were used to obtain the highest amount of organic acid derivatives from saffron stigmas. To the best of our knowledge, this is the first report of the quantitative and qualitative GC/MS detection of organic acids in saffron stigmas using MTBSTFA reagent, also comparing different derivatization conditions, such as time, temperature and the effect of reagent amount on derivatization process. The identification of these derivatives was performed via GC-electron impact ionization mass spectrometry in positive-ion detection mode. Under optimal conditions, excellent linearity for all organic acids was obtained with determination coefficients of R² > 0.9955. The detection limits (LODs) and quantitation limits (LOQs) ranged from 0.317 to 0.410 µg/mL and 0.085 to 1.53 µg/mL, respectively. The results showed that the highest yield of organic acids was conducted by using 0.1 mL of MTBSTFA and derivatization method with a conventional heating process at 130 °C for 90 min. This method has been successfully applied to the quantitative analysis of organic acids in saffron stigmas.

Polychlorinated Biphenyl Profile in Polyhydroxy-alkanoates Synthetized from Urban Organic Wastes

The microbial synthesis of polyhydroxyalkanoates (PHA) from organic wastes is a valuable process to valorize available renewable resources, such as food wastes and biological sludge. Bioplastics find many applications in various sectors, from medical field to food industry. However, persistent organic pollutants could be transferred from wastes to the final product. The present paper demonstrates that the use of municipal wastes in PHA production is safe for the environment and human health and provides a polychlorinated biphenyl (PCB) profile in both commercial and waste-based PHA samples. PCB analysis in several PHA samples showed very low concentrations of the target analytes. Commercial PHA samples showed a similar PCB level with respect to PHA samples from municipal waste/sludge and higher than PHA samples from fruit waste. For all analyzed PCBs, detected concentrations were consistently lower than the ones reported in regulatory framework or guidelines.

An Evidence Synthesis of Pharmaceuticals and Personal Care Products (PPCPs) in the Environment: Imbalances among Compounds, Sewage Treatment Techniques, and Ecosystem Types

Pharmaceuticals and personal care products (PPCPs) garner increasing attention globally for both their usefulness as indicators of human waste and their potency as emerging organic toxicants. Three decades of rapid increase in PPCP study combined with an increasing number of PPCPs on the global market have created an opportunity (1) to review trends in diversity of compounds, sewage treatment techniques (STTs), and ecosystems investigated as well as (2) to identify knowledge gaps in the literature. We conducted a quantitative evidence synthesis of 6517 abstracts from primary articles in the environmental PPCP literature by examining relative abundance of specific PPCP classes, STTs, and ecosystem types. Our results demonstrate that non-prescription drugs and antibiotics dominated PPCP abstracts, appearing in 51% and 39% of reviewed abstracts, respectively, in comparison to hormones (18%), prescription drugs (18%), fragrances (0.3%), and antioxidants (0.0%), which can all elicit physiological and ecological responses even at low concentrations. References to centralized STTs (e.g., activated sludge, 37%) were more frequent than decentralized STTs (e.g., septic, 2%), despite decentralized STTs being common and frequently high impact sources of sewage pollution worldwide. Freshwater lotic systems (63%) were more prevalent than freshwater lentic (24%) and terrestrial (20%) systems. This discrepancy is notable because the longer residence times of lentic and terrestrial systems may enable PPCPs to concentrate and thus increase risk of biological consequences. These results highlight distinct opportunities to address knowledge gaps in the environmental PPCP literature, including underrepresented compounds (e.g., fragrances), sewage treatment techniques (e.g., septic systems), and ecosystem types (e.g., lakes).

Presence and Natural Treatment of Organic Micropollutants and their Risks after 100 Years of Incidental Water Reuse in Agricultural Irrigation

The aim of the research was to show the presence of micropollutants contained in the wastewater of Mexico City within the distribution canals of the Mezquital Valley (MV), as well as their retention in agricultural soil and aquifers. This system constitutes the world's oldest and largest example of the use of untreated wastewater for agricultural irrigation. The artificial recharge associated with the MV aquifers, with groundwater extracted for human consumption showing its importance as a water resource for Mexico City. The results of sampling show the presence of 18 compounds, with 10 of these considered as endocrine disruptor compounds (EDCs). The concentration of these pollutants ranged from 2 ng/L for 17 β-estradiol to 99 ng/L for DEHP, with these values decreasing throughout the course of the canals due to the wastewater dilution factor, their retention in agricultural soil, and their accumulation in the local aquifer. The main mechanisms involved in natural attenuation are adsorption, filtration, and biodegradation. Drinking water equivalent levels (DWELs) were estimated for 11 compounds with regard to acceptable daily intakes (ADIs), by assuming local exposure parameters for a rural Mexican population. These were compared with the maximum groundwater concentrations (Cgw) to screen the potential risks. The very low ratios of Cgw to DWELs indicate no appreciable human health risk from the presence of trace concentrations of these compounds in the source of drinking water in the MV. Despite this, far from being exceeded after more than 100 years of irrigation with residual water, the natural soil attenuation seems to remain stable.

Determination of twenty pharmaceutical contaminants in soil using ultrasound-assisted extraction with gas chromatography-mass spectrometric detection

In this paper, an analytical method for the simultaneous determination of twenty pharmaceuticals (eight non-steroidal anti-inflammatory drugs, five oestrogenic hormones, two antiepileptic drugs, two β-blockers, and three antidepressants) in soils was developed. The optimal method included ultrasound-assisted extraction, a clean-up step on a silica gel column, derivatization using N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) and 1% trimethylchlorosilane (TMCS) in pyridine and ethyl acetate (2:1:1, v/v/v) for 30 min at 60 °C, and determination by gas chromatography-mass spectrometry working in the selected ion monitoring mode. This affords good resolution, high sensitivity and reproducibility, and freedom from interferences even from complex matrices such as soils. The method detection limits ranged from 0.3 to 1.7 ng g^-1, the intra-day precision represented as RSDs ranged from 1.1 to 10.0%, and the intra-day accuracy from 81.3 to 119.7%. The absolute recoveries of the target compounds were above 80%, except for valproic acid and diethylstilbestrol. The developed method was successfully applied in the analysis of the target compounds in soils collected in Poland. Among the 20 pharmaceuticals, 12 compounds were detected at least once in the soils. The determination of antiepileptic drugs, β-blockers, and antidepressants was also performed for the first time.

A Rapid and Green Method for the Determination of Veterinary Pharmaceuticals in Swine Wastewater by Fluorescence Spectrophotometry

A growing concern exists over water contamination by veterinary pharmaceuticals from small pig farms in Yucatan, Mexico, where the anaerobic digesters installed as the wastewater treatment system are not operated properly. Therefore, considerable interest exists to develop analytical methods to detect these compounds and characterize their fate in the environment. In this study, the detection of three antibiotics (enrofloxacin, oxytetracycline and sulfamethoxazole) and a β-agonist (ractopamine) was carried out using fluorescence spectrophotometry, with a semi-quantitative approach and a low environmental impact. Wastewater samples from 10 pig farms were analyzed, detecting concentrations of approximately 0.043 μg mL^-1 for enrofloxacin, 1.427 μg mL^-1 for oxytetracycline, and 9.748 μg mL^-1 for sulfamethoxazole. The detection of these pharmaceuticals in the effluents of treated wastewater from the biodigesters of the pig farms suggests the need to optimize the system and prevent the entry of these compounds into the environment.

Distribution and Chemical Analysis of Pharmaceuticals and Personal Care Products (PPCPs) in the Environmental Systems: A Review

PPCPs are found almost everywhere in the environment especially at an alarming rate and at very low concentration in the aquatic systems. Many methods-including pressurized hot water extraction (PHWE), pressurized liquid extraction (PLE), ultrasound-assisted extraction (UAE), and micro-assisted extraction (MAE)-have been employed for their extraction from both surface waters and biota. Solid-phase extraction (SPE) proved to be the best extraction method for these polar, non-volatile, and thermally unstable compounds in water. However, ultrasonic extraction works better for their isolation from sediment because it is cheap and consumes less solvent, even though SPE is preferred as a clean-up method for sediment samples. PPCPs are in groups of-acidic (e.g., diclofenac, ibuprofen, naproxen), neutral (e.g., caffeine, carbamazepine, fluoxetine), and basic pharmaceuticals, as well as antibiotics and estrogens amongst others. PPCPs which are present in trace levels (ng/L) are more often determined by liquid chromatography-mass spectrometry (LC-MS), gas chromatography-mass spectrometry (GC-MS), and high-performance liquid chromatography-ultraviolent (HPLC-UV). Of these, LC-MS and LC-MS-MS are mostly employed for the analysis of this class of compounds, though not without a draw-back of matrix effect. GC-MS and GC-MS-MS are considered as alternative cost-effective methods that can also give better results after derivatization.

Quantification of multi-classes of endocrine-disrupting compounds in estuarine water

Emerging pollutants known as endocrine-disrupting compounds (EDCs) are a contemporary global issue, especially in aquatic ecosystems. As aquaculture production through mariculture activities in Malaysia supports food production, the concentration and distribution of EDCs in estuarine water ecosystems may have changed. Therefore, this current study aims to prepare a suitable and reliable method for application on environmental samples. Besides, this study also presented the occurrence of EDCs pollutant in Pulau Kukup, Johor, where the biggest and most active mariculture site in Malaysia takes place. Analytical methods based on a combination of solid-phase extraction with liquid chromatography tandem mass spectrometry (Solid-phase extraction (SPE)-LC-MS/MS) have been modified and optimised to examine the level of targeted EDCs contaminant. In the current study, this method displays high extraction recovery for targeted EDCs, ranging from 92.02% to 132.32%. The highest concentration detected is diclofenac (<0.47-79.89 ng/L) followed by 17β-estradiol (E2) (<5.28-31.43 ng/L) and 17α-ethynylestradiol (EE2) (<0.30-7.67 ng/L). The highest percentage distribution for the targeted EDCs in the current study is diclofenac, followed by EE2 and dexamethasone with the percentages of 99.44%, 89.53% and 73.23%, respectively. This current study can be a baseline assessment to understand the pollution profile of EDCs and their distribution in the estuarine water of the mariculture site throughout the world, especially in Malaysia. Owing to the significant concentration of targeted EDCs detected in water samples, the need for further monitoring in the future is required.

Analysis and fate of 14 relevant wastewater-derived organic pollutants in long-term exposed soil

The growing use of reclaimed water in agriculture worldwide calls for developing high-sensitivity methods to quantify wastewater-derived organic contaminants in soils so that the potential risk of this irrigation practice can be properly assessed. This work describes an analytical method for the determination of trace levels of 14 drugs that are known to be poorly removed during conventional wastewater treatment in soil. The analytes selected for investigation included ten pharmaceuticals from different therapeutic classes (carbamazepine, diclofenac, cis-diltiazem, lamotrigine, methadone, midazolam, oxcarbazepine, sulfamethoxazole, trimethoprim, valsartan), one illicit drug (cocaine), and three transformation products/metabolites (acridone, 4'-hydroxydiclofenac, and valsartan acid), thereby covering a broad range of physical-chemical properties. The methodology developed was based on ultrasonic solvent extraction (USE) of the analytes from the soil matrix, and subsequent clean-up and analysis of the USE extracts with a fully automated approach by means of solid-phase extraction and liquid chromatography-tandem mass spectrometry detection (online SPE-LC-MS/MS). The method was fully validated with affording method detection and quantification limits ranging from 0.03 to 1 ng g^-1 and from 0.09 to 3.3 ng g^-1, respectively. This method was applied to investigate the fate of the selected drugs in potting soil irrigated for a long term (60 days) either with water containing the target compounds at a concentration of 200 μg L^-1 or with wastewater treatment plant effluent and thus, at real environmental concentrations. All investigated compounds were found to accumulate in soil irrigated with artificially fortified water. The highest accumulation potential was observed for cis-diltiazem followed by methadone and midazolam that presented average concentrations of 1517 ng g^-1, 1041 ng g^-1, and 962 ng g^-1 d.w., respectively. On the contrary, oxcarbazepine (5.8 ng g^-1) and sulfamethoxazole (22 ng g^-1) were the target drugs presenting the lowest accumulation potential. Only trace levels of ten drugs were measured in soil irrigated with regenerated water (average concentrations between 1.6 and 4.7 ng g^-1 d.w.). Graphical abstract.

Transformation Products of Organic Contaminants and Residues-Overview of Current Simulation Methods

The formation of transformation products (TPs) from contaminants and residues is becoming an increasing focus of scientific community. All organic compounds can form different TPs, thus demonstrating the complexity and interdisciplinarity of this topic. The properties of TPs could stand in relation to the unchanged substance or be more harmful and persistent. To get important information about the generated TPs, methods are needed to simulate natural and manmade transformation processes. Current tools are based on metabolism studies, photochemical methods, electrochemical methods, and Fenton’s reagent. Finally, most transformation processes are based on redox reactions. This review aims to compare these methods for structurally different compounds. The groups of pesticides, pharmaceuticals, brominated flame retardants, and mycotoxins were selected as important residues/contaminants relating to their worldwide occurrence and impact to health, food, and environmental safety issues. Thus, there is an increasing need for investigation of transformation processes and identification of TPs by fast and reliable methods.

Simultaneous Determination of Pharmaceuticals by Solid-phase Extraction and Liquid Chromatography-Tandem Mass Spectrometry: A Case Study from Sharjah Sewage Treatment Plant

The present work describes the optimization and validation of a highly selective and sensitive analytical method using solid phase extraction and liquid chromatography tandem mass spectrometry (SPE LC-MS/MS) for the determination of some frequently prescribed pharmaceuticals in urban wastewater received and treated by Sharjah sewage treatment plant (STP). The extraction efficiency of different SPE cartridges was tested and the simultaneous extraction of pharmaceuticals was successfully accomplished using hydrophilic-lipophilic-balanced reversed phase Waters^® Oasis HLB cartridge (200 mg/ 6 mL) at pH 3. The analytes were separated on an Aquity BEH C18 column (1.7 µm, 2.1 mm × 150 mm) using gradient elution and mass spectrometric analysis were performed in multiple reactions monitoring (MRM) selecting two precursor ions to produce ion transition for each pharmaceutical using positive electrospray ionization (+ESI) mode. The correlation coefficient values in the linear calibration plot for each target compound exceeded 0.99 and the recovery percentages of the investigated pharmaceuticals were more than 84%. Limit of detection (LOD) varied between 0.1–1.5 ng/L and limit of quantification (LOQ) was 0.3–5 ng/L for all analytes. The precision of the method was calculated as the relative standard deviation (RSD%) of replicate measurements and was found to be in the ranges of 2.2% to 7.7% and 2.2% to 8.6% for inter and intra-day analysis, respectively. All of the obtained validation parameters satisfied the requirements and guidelines of analytical method validation.

Determination of Micropollutants in Water Samples from Swimming Pool Systems

The present study investigated the occurrence of selected micropollutants, including emerging contaminants from a group of pharmaceuticals and personal care products (PPCPs) in water samples from swimming pool systems. The study area was selected based on the lack of available information regarding suspected contamination of swimming pool water by PPCPs. The variety and concentration of chemical compounds in these aquatic systems can be quite diversified, presenting a challenge in terms of both purification and quality control. Determination of PPCPs requires very sensitive analytical methods that make it possible to confirm the presence of tested compounds in a complex organic extract. In this field, gas chromatography-mass spectrometry (GC-MS) can be used. With this system, selected ion monitoring can be performed, which reduces the detection limits of the investigated analyte. This paper aims to present an analytical method and strategy that can be adapted to obtain information on the composition of water in swimming pool systems. The sample preparation methodology, including Solid Phase Extraction, has been developed for the trace determination of two pharmaceuticals—caffeine, carbamazepine—and one sunscreen constituent—benzophenone-3—in swimming pool water samples.

Simultaneous Determination of Amphetamine-Related New Psychoactive Substances in Urine by Gas Chromatography–Mass Spectrometry†

Despite the efforts to prevent the spread of new psychoactive substances (NPS) such as synthetic amphetamine derivatives, it is apparent that newer types of NPS are still emerging on the market in recent years. Due to high potential for their abuse, reliable analytical methods are required to determine these substances in biological samples. The objective of this study was to develop and validate the gas chromatography–mass spectrometric (GC–MS) method for the simultaneous determination of 13 amphetamine-related NPS (amphetamine; AP, 4-fluoroamphetamine; 4FA, methamphamine; MA, 4-fluoromethamphetamine; 4FMA, 4-chloroamphetamine; 4CA, para-methoxyamphetamine; PMA, 4-chloromethamphetamine; 4CMA, 6-(2-aminopropyl)benzofuran; 6APB, 4-methylenedioxyamphetamine; MDA, para-methoxymethamphetamine; PMMA, 6-(2-methylaminopropyl)benzofuran; 6MAPB, 3,4-methylenedioxymethamphetamine; MDMA, 5,6-methylenedioxy-2-aminoindane; MDAI) in urine. The analytes were extracted at pH 7.4 by liquid–liquid extraction prior to their trifluoroacetyl derivatives and then analyzed by GC–MS. The validation parameters included selectivity, linearity, lower limits of quantification (LLOQ), intra and interday precision and accuracy, recovery and stability. The linear ranges were 2–100 ng/mL for AP, 4FA, 4FMA, 4CA, PMA, 6APB, MDA, and MDAI, 2–250 ng/mL for 4CMA, PMMA, and 6MAPB and 25–1,000 ng/mL for MA and MDMA, with acceptable coefficients of determination (r2 > 0.9963). The intra and interday precision were within 11.9 and 12.5%, while the intra and interday accuracies ranged from −10.6% to 13.0% and −11.0% to 6.8% for the nominal concentration at all studied levels, respectively. The LLOQs for each analyte were 2.0–25 ng/mL. The recoveries ranged from 69.3% to 96.4%. The short- and long-term variations of the analytes in urine were lower than 8.5 and 12.7%, indicating that the analytes are stable at least for 16 h at room temperature and for 7 days at 4°C, respectively. The applicability of the method was examined by analyzing urine samples from drug abusers and was determined to be effective for detecting multiple drug use.

Magnetic microsphere-based portable solid phase extraction device for on-site pre-concentration of organics from large-volume water samples

In this research a new magnetic material called M88 was fully synthetized and characterized for the extraction of pharmaceutical and personal care products in water samples. In addition, a portable prototype of magnetic solidphase extraction (MSPE) device was developed for the onsite preconcentration. The MSPE coupling with high performance liquid chromatography-Diode array detector (HPLC-DAD) method was developed and validated for simultaneous analysis of 11 PPCPs (mefenamic acid, chloroamphenicol, ketoprofen, clofibric acid, indometacin, acetylsalicylic acid, bisphenol A, phenylphenol, gemfibrozil, triclosan, and ibuprofen) in environmental water samples. Experimental parameters affecting the extraction efficiencies, such as the amount of M88, desorption solvent, extraction time, and solution pH and sample volume were investigated. Under the optimal conditions, the limits of detection (LODs, S/N = 3) for the selected PPCPs were found to be in the range of 0.7-9.4 ng/L, with good linear correlation coefficients. It is also shown that the extraction efficiency of M88 was comparable to that of the commercial Oasis HLB and was evidently higher than that of the C18 cartridge. The optimised method was further verified by performing spiking experiments in water samples from Taihu Lake, with good recovery and reproducibility for all the compounds.

Assessment of nonsteroidal anti-inflammatory drugs by ultrasonic-assisted extraction and GC-MS in Mgeni and Msunduzi river sediments, KwaZulu-Natal, South Africa

The occurrence of eight pharmaceuticals was monitored during four seasons (spring, summer, autumn, and winter) along a 250-km stretch of the Msunduzi and Mgeni rivers in KwaZulu-Natal, South Africa. This paper describes an optimized method for the determination of nonsteroidal anti-inflammatory drugs (NSAIDs) in sediments. The method combines ultrasonic, centrifuge, and gas chromatography-mass spectrometry for the detection of these drugs in solid samples. Most of the parameters that affect the extraction step were optimized. Solid samples were placed in a centrifuge tube and extracted with ethyl acetate:acetone (1:1, two cycles), followed by clean-up with Oasis HLB cartridge and derivatization with N, O-bis(trimethylsilyl) trifluoroacetamide (BSTFA). Satisfactory recoveries were obtained ranging from 66 to 130%, depending on the analyte. Precision expressed as RSD (%) (n = 3) was less than 20% for all analytes. The LODs and LOQs were in the range of 0.024 to 1.90 ng g^-1 which allowed to be applied in the analysis solid samples in Msunduzi and Mgeni rivers. In the solid samples analyzed, NSAID concentration ranged from not detected to 221 ng g^-1.

Detection and quantification of acidic drug residues in South African surface water using gas chromatography-mass spectrometry

A method was optimized for derivatization, separation, detection and quantification of salicylic acid, acetylsalicylic acid, nalidixic acid, ibuprofen, phenacetin, naproxen, ketoprofen, meclofenamic acid and diclofenac in surface water using gas chromatography-mass spectrometry. For most of the acidic drugs, recovery was in the range 60-110% and the percent standard deviation was below 15% for the entire method, with limits of detection ranging from 0.041 to 1.614 μg L^-1. The developed method was applied in the analysis of acidic drugs in Umgeni River system, KwaZulu-Natal South Africa. All of the selected acidic drugs were detected and quantified, their concentration in Umgeni River system ranged from 0.0200 to 68.14 μg L^-1.