Extraction improvement of ionic liquid-functionalized silica by in situ anion-exchange for online solid-phase extraction of estrogens in honey

The accurate detection of analytes in honey is affected by the complex substrates, making it crucial to employ an effective sample preparation technique. In this work, an imidazolium ionic liquid was functionalized to the silica surface by a click reaction for solid-phase extraction (SPE) column, and in situ anion-exchange process was performed with different organic anions (dodecyl sulfonate, dodecyl benzene sulfonate, and naphthalene sulfonate). These SPE columns were evaluated through extracting the estrogens. The naphthalene sulfonate-based SPE column displayed the best extraction ability among these, and it was combined with high-performance liquid chromatography-diode array detection to establish an online enrichment and analysis system. Under the optimal test conditions, an online analytical method was developed, with high enrichment factors (1872-4744), wide linear ranges (0.0033-1.50, 0.0165-1.50, and 0.0330-1.50 μg g-1), and low detection limits (0.001-0.010 μg g-1). The method successfully determined several estrogens in some honey samples, and achieved satisfactory recovery results.

Switchable deep eutectic solvent as green and efficient media for liquid-phase microextraction of phenoxyacetic acid herbicides in water and food matrices

In this work, a switchable deep eutectic solvent (SDES) based on fatty acid and polyetheramine ion pair was prepared for liquid-phase microextraction (LPME) of phenoxyacetic acid herbicides in drinking water, beverage and honey matrices. The as-synthesized SDES equipped with an interesting characteristic of fast and reversible polarity switching, achieving homogeneous extraction and rapid bi-phase separation simultaneously. Several key parameters affecting the extraction performance were investigated comprehensively by Box-Behnken design. Under the optimal conditions, the method exhibited excellent linearity (15-4000 μg L-1), low detection limits (3-5 μg L-1), desirable precision (RSD < 8.1 %), and satisfactory recovery (72.6-98.7 %). More importantly, the introduction of SDES can simplify the pre-treatment procedure, shorten extraction time (4 min), and avoid the usage of traditional organic solvent during the whole extraction process. In addition, the switching mechanism of SDES was characterized by FT-IR and 1H NMR, and the forming mechanism of SDES was investigated using density-functional theory. The green of the method was estimated using the analytical ecological scale, the analytical green calculator, and the green analytical procedure index. The cytotoxicity of SDES was investigated and the result displayed that toxicity of the SDES was very low with the EC50 > 500 mg/L. Therefore, the proposed method was green and efficient and revealed considerable application prospects for the extraction of trace analytes from complex materials.

High-Performance enrichment and sensitive analysis of bisphenol and its analogues in water and milk using a novel Ni-Based cationic Metal-Organic framework

A novel cationic metal-organic framework (iMOF-Ni) was designed and synthesized by a solvothermal method. It was fabricated as a solid-phase extraction (SPE) cartridge and exhibited high adsorption performance for Bisphenols (BPs). The theoretical simulation demonstrated that the adsorption mechanism between iMOF-Ni and BPs was attributed to cation-π bonding, π-π interaction, and electrostatic interactions. Under optimized SPE, a method for analyzing BPs was established by combining high-performance liquid chromatography-diode array detection (HPLC-DAD). The developed method has good linearity (R2 ≥ 0.994), low detection limits (0.07-0.16 ng/mL), and good reproducibility (1.72-6.35 %, n = 6). The applicability of the method was further evaluated by analyzing water and milk samples. Recoveries of four BPs in spiked samples were from 72.2 % to 96.6 %.

Evaluation of the antimalarial and CD4+ T-cell modulatory effects of leaf methanol extract of Phyllanthus muellerianus (Kuntze) Exell (Phyllanthaceae) in Plasmodium berghei-infected mice

ETHNOPHARMACOLOGICAL RELEVANCE

Phyllanthus muellerianus (Kunze) Exell, a member of the Phyllanthaceae family, is a medicinal plant widely distributed in Africa. Decoctions from the leaves are used in Nigeria to treat fevers, convulsions, some neurological disorders and malaria.

AIM OF THE STUDY

This study is to evaluate the anti-malarial properties of methanol extract of Phyllanthus muellerianus (MEPM) leaves and its ethyl acetate fraction using a murine malaria model infected with Plasmodium berghei. Additionally, we seek to investigate the potential modulatory effects of this extract and fraction on CD4+ T-cell populations in the context of malaria infection.

MATERIALS AND METHODS

The anti-malarial effects of the leaf methanol extract of Phyllanthus muellerianus (MEPM) were screened using three established in vivo models of anti-plasmodial screening namely the curative, suppressive and prophylactic models. The methanol extract (MEPM) was afterwards fractionated into hexane (HFPM), ethyl acetate (EAFPM), and methanol (MFPM) fractions. In the pilot anti-malarial screening of the fractions, EAFPM exhibited the best antiparasitic activity. Subsequently, EAFPM was screened for anti-malarial activity using the three models above. The effects of the MEPM and EAFPM on haematological indices (Hb and PCV) of the inoculated animals were further screened and the mean survival time (MST) of the animals was monitored. CD4+ T cells of various groups were counted before and after treatment using a flow cytometer. The EAFPM was further subjected to HPLC analysis for identification of its major compounds.

RESULTS

The EAFPM (100 and 200 mg/kg) elicited 88% and 93% cure respectively in the curative model, while artesunate (5 mg/kg,- the positive control) gave 87% protection. The MEPM and EAFPM also gave significant suppression of parasitemia in the suppressive model. The treated groups survived beyond 28 days as against 11 days by the control group (infected but not treated). The treated groups also prevented anaemia seen in the negative control. The EAFPM group significantly modulated the CD4+ T cell. Compounds identified were Gallocatechin, Quercetin -3-O-gallate, Ellagic acid, and Methylellagic acid rhamnoside).

CONCLUSION

The study established that the leaf of Phyllanthus muellerianus possesses antimalarial activity, thus lending support to its use in the folkloric treatment of malaria.

Connecting Bisphenol A Exposure to PCOS: Findings from a Case-Control Investigation

Polycystic Ovary Syndrome (PCOS) is a multifaceted condition influenced by genetic, hormonal, and environmental factors. Among environmental factors, Bisphenol A (BPA)-a recognized endocrine disruptor-has been implicated in the development of PCOS. The study aimed to compare BPA levels in women diagnosed with PCOS with those in healthy controls, using the high-performance liquid chromatography (HPLC) technique. The study involved 80 women diagnosed with PCOS and 50 healthy control participants. Demographic and biochemical parameters were recorded, including age, Body Mass Index (BMI), and levels of testosterone, estradiol, Luteinizing Hormone (LH), Follicle Stimulating Hormone (FSH), Prolactin (PRL), Dehydroepiandrosterone Sulfate (DHEA-S), Thyroid Stimulating Hormone (TSH), and Insulin Resistance as measured by the Homeostatic Model Assessment (HOMA-IR). Furthermore, BPA levels were measured using the HPLC technique. Women with PCOS exhibited significantly higher mean age and BMI compared to healthy controls (p = 0.01, p < 0.0001, respectively). Additionally, higher levels of testosterone (p = 0.04), LH (p = 0.03) and BPA (p < 0.0001) were observed in women with PCOS. However, estradiol, FSH, PRL, LH/FSH ratio, DHEA-S, and TSH levels were not significantly different between the two groups. HOMA-IR levels were not recorded for the control group. A notable positive relationship emerged between Bisphenol A and luteinizing hormone (LH) levels (r = 0.23, p = 0.03), also significant negative correlation appeared between Bisphenol A and thyroid-stimulating hormone (TSH) levels. This study found that women with PCOS have elevated BPA levels compared with healthy controls, showing a need for further research on the relationship between BPA exposure and the development of PCOS.

Exploring the mechanism of probiotics in enhancing the utilization of chemical components (or polyphenols) of grape seed extract

Fecal samples from 20 healthy adults were collected for in vitro fermentation experiments to investigate the effects of combined probiotics on the utilization of grape seed extract in humans. After fermenting for 24 h, short-chain fatty acids, metabolites, and gut microbiota composition were analyzed. Short-chain fatty acids in the grape seed extract probiotics group were significantly higher than those in the grape seed extract group. Probiotics significantly enhanced the conversion and utilization of catechins and epicatechins in grape seed extract group and increased the production of 3-hydroxyphenylacetic acid. The 16S rRNA sequencing results revealed that compound probiotics significantly increased the relative abundance of Lacticaseibacillus, HT002, Bifidobacterium, and Lactobacillus and reduced that of Escherichia-Shigella. Our findings showed considerable individual variability in the metabolic utilization of grape seed extract in humans. The consumption of probiotics appears to significantly enhance the utilization.

Development of a hollow fiber-liquid phase microextraction method using tissue culture oil for the extraction of free metoprolol from plasma samples

In this research, a method known as a hollow fiber-liquid-phase microextraction was employed to extract and concentrate free metoprolol from plasma samples. The extracted analyte was subsequently determined using high-performance liquid chromatography coupled with a diode-array detector. Several parameters, including hollow fiber length, sonication time, extraction temperature, and salt addition, were investigated and optimized to enhance extraction efficiency. After extracting the analyte under optimum conditions from plasma samples, the enrichment factor and extraction recovery were 50 and 86 %, respectively. Moreover, the method exhibited detection and quantification limits of 0.41 and 1.30 ng mL-1, respectively. The analysis of real samples demonstrated satisfactory relative recoveries in the range of 91-99 %.

Individual and total sugar contents of street foods in Malaysia - Should we be concerned?

Street foods are often of poor nutritional quality with high sugar content, in which the overconsumption of sugar is associated with obesity. However, sugar content information on local street foods is scarce. Thus, the individual and total sugar contents of 94 types of street foods in Malaysia were analysed. Compared to snacks and main meals, desserts contained the highest amounts of sugar, sucrose, fructose, glucose, and maltose. Sucrose was predominant in 90% desserts, 79.3% snacks, and 68.6% main meals. Most desserts (93.3%) contained medium to high sugar content (≥5 g to >15 g/100 g), while 82.9% main meals and 65.5% snacks had low sugar content. When comparing the sugar contents of 39 foods with other local databases, 58.3% main meals, 55.6% desserts, and 33.3% snacks contained either significantly (p < 0.05) higher or lower sugar contents. Consumers can identify low and high-sugar foods, and policymakers can review health priorities to combat obesity.

Facile synthesis of amino-modified magnetic covalent organic framework for the efficient extraction and determination of anionic azo dyes in carbonated beverages

In this work, a novel magnetic covalent organic framework (COF (TpPa-NH2) @ Fe3O4) was prepared via two step by simple solvent method for the extraction of anionic azo dye residues in food. The as-prepared COF (TpPa-NH2) @ Fe3O4 nanocomposite was characterised by scanning electron microscope, transmission electron microscope, Fourier transform-infrared spectroscopy, X-ray diffraction and vibrating sample magnetometer. Before high-performance liquid chromatography with ultraviolet detection (HPLC-UV) determination, it was used as magnetic adsorbent for magnetic solid-phase extraction (MSPE) to extract and pre-concentrate three anionic azo dyes in carbonated beverage samples. The several key extraction and desorption parameters affecting the extraction recovery rate were investigated, including extraction time, pH of the solution, amount of material, adsorption time, elution solvent, pH of elution solvent, type of elution solvent, elution volume and elution time. Under optimised conditions, this method has good linearity between 5 and 500 μg L-1 (correlation coefficient > 0.9986). The limit of detection was 2.3-3.4 μg L-1. The recoveries of the samples were between 87.5 and 96.9%, and the relative standard deviation lower than 4.6%. The developed method has broad application prospects for the analysis of anionic azo dyes in carbonated beverages.

Endocrine-disrupting chemicals and hormonal profiles in PCOS women: A comparative study between urban and rural environment

Polycystic Ovary Syndrome (PCOS), a multifaceted endocrine disorder, affects a significant proportion of women globally, with its etiology rooted in both genetic and environmental factors. This study delves into the environmental aspect, particularly focusing on the role of endocrine-disrupting chemicals (EDCs) in the context of urbanization and industrialization. This research examines the impact of endocrine-disrupting chemicals (EDCs) - Bisphenol A (BPA), Mono-ethyl Hexyl Phthalate (MEHP), and Di-ethyl Hexyl Phthalate (DEHP) - on 40 women with Polycystic Ovary Syndrome (PCOS) across urban and rural Gujarat. Employing High-Performance Liquid Chromatography (HPLC) and chemiluminescence, we analyzed their blood samples for EDCs levels and hormonal parameters. Urban individuals displayed significantly higher BPA and DEHP concentrations, highlighting the environmental exposure differences. Notably, urban exposure to MEHP and DEHP correlated with a marked decrease in estradiol levels, while rural DEHP exposure was associated with an increase in estradiol but a decrease in prolactin and DHEAS levels. These findings illuminate the variable effects of EDC exposure on hormonal profiles in PCOS, influenced by geographical and environmental contexts. The study underscores the critical need for tailored environmental health policies to mitigate the diverse impacts of EDCs, advocating for a nuanced approach to PCOS management that considers environmental exposures. Our insights contribute to the understanding of PCOS's hormonal dynamics, emphasizing the significance of addressing EDC exposure in different settings.

Selective adsorption and identification of penicillin G sodium in milk by molecularly imprinted polymer doped carbon dot

A carbon dot (CD) was prepared by o-phenylenediamine and water, which showed bright yellow fluorescence under ultraviolet light irradiation (λ = 580 nm), and verified good fluorescence quenching effect on penicillin G sodium (Png-Na). Using methacrylic acid as a functional monomer, ethylene glycol dimethacrylate as a crosslinker, and Png-Na as a template, a kind of composite microsphere combining CD and molecularly imprinted polymer (MIP) was synthesized by surface-initiated atomic transfer radical polymerization (SI-ATRP). For reasons of comparison, we also prepared MIP without CD and non-imprinted polymers (NIPs). Through static and dynamic adsorption experiments, the maximum adsorption capacity was 47.05 mg g-1 and the equilibrium time was 30 min. High-performance liquid chromatography (HPLC) was utilized to determine the content of Png-Na in the spiked milk samples. A sensitive, rapid, and simple method for determination of Png-Na in food samples was developed. The utilized approach enabled the quantification of Png-Na within the concentration range 20-1000 μg L-1 (with a limit of detection of 5 μg L-1). The recoveries achieved were in the range 93.3-98.2%, with a relative standard deviation of 1.2-4.2%. The results demonstrated that CD@MIP possessed the capability of specific adsorption and fluorescence detection of Png-Na, enabling simultaneous detection and enrichment of Png-Na in real samples.

Improved quantitative analysis of tenuifolin using hydrolytic continuous-flow system to build prediction models for its content based on near-infrared spectroscopy

This study used two types of analyses and statistical calculations on powdered samples of Polygala root (PR) and Senega root (SR): (1) determination of saponin content by an independently developed quantitative analysis of tenuifolin content using a flow reactor, and (2) near-infrared spectroscopy (NIR) using crude drug powders as direct samples for metabolic profiling. Furthermore, a prediction model for tenuifolin content was developed and validated using multivariate analysis based on the results of (1) and (2). The goal of this study was to develop a rapid analytical method utilizing the saponin content and explore the possibility of quality control through a wide-area survey of crude drugs using NIR spectroscopy. Consequently, various parameters and appropriate wavelengths were examined in the regression analysis, and a model with a reasonable contribution rate and prediction accuracy was successfully developed. In this case, the wavenumber contributing to the model was consistent with that of tenuifolin, confirming that this model was based on saponin content. In this series of analyses, we have succeeded in developing a model that can quickly estimate saponin content without post-processing and have demonstrated a brief way to perform quality control of crude drugs in the clinical field and on the market.

Non-targeted analytical comparison of a heated tobacco product aerosol against mainstream cigarette smoke: does heating tobacco produce an inherently different set of aerosol constituents?

Smoking-related diseases remain a significant public health concern, and heated tobacco products (HTPs) have emerged as a potential alternative to cigarettes. While several studies have confirmed that HTP aerosols contain lower levels of harmful and potentially harmful constituents (HPHCs) than cigarette smoke, less is known about constituents that are intrinsically higher in HTP aerosols. This study provides a comprehensive comparative assessment of an HTP aerosol produced with Tobacco Heating System 2.2 (THS) and comparator cigarette (CC) smoke aiming at identifying all unique or increased compounds in THS aerosol by applying a broad set of LC-MS and GC × GC-MS methods. To focus on differences due to heating versus burning tobacco, confounding factors were minimized by using the same tobacco in both test items and not adding flavorants. Of all analytical features, only 3.5%-corresponding to 31 distinctive compounds-were significantly more abundant in THS aerosol than in CC smoke. A notable subset of these compounds was identified as reaction products of glycerol. The only compound unique to THS aerosol was traced back to its presence in a non-tobacco material in the test item and not a direct product of heating tobacco. Our results demonstrate that heating a glycerol-containing tobacco substrate to the temperatures applied in THS does not introduce new compounds in the resulting aerosol compared to CC smoke which are detectable with the method portfolio applied in this study. Overall, this study contributes to a better understanding of the chemical composition of HTP aerosols and their potential impact on human health.

A novel and sensitive method for simultaneous determination of 6 low-calorie bulk sweeteners by HPLC-ELSD

A novel and sensitive method for the simultaneous analysis of six low-calorie bulk sweeteners (D-allulose, D-tagatose, D-mannitol, mycose, palatinose, and erythritol) without derivatisation was developed using high-performance liquid chromatography-evaporative light scattering detector (HPLC-ELSD). Chromatographic separations were carried out on a Zorbax Original NH2 (5 μm particle size, 250 mm×4.60 mm id, 70 Å) column with flow rate gradient elution with acetonitrile: water (80:20, v/v). Drift tube temperature was set at 50 ℃, the nebuliser carrier gas flow rate was 1.0 mL·min-1, and nitrogen pressure was regulated to 276 kPa with gain:3. The regression equation showed good linearity (R2 = 0.9985-0.9998) for all six low-calorie bulk sweeteners in the tested range (0.060-0.60 mg·mL-1). The limits of detection (LOD) for the six low-calorie bulk sweeteners ranged from 0.02 to 0.06 mg·mL-1. The proposed HPLC-ELSD method was validated for the quantification of the low-calorie bulk sweeteners in 14 types of foods, and the results were satisfactory. In addition, the results showed that the number of sweeteners in each food product varied. The presence of multiple low-calorie bulk sweeteners in certain foods is interesting. This method is successful in monitoring low-calorie bulk sweeteners in food.

Fluorine-functionalized covalent organic framework as efficient solid phase extraction sorbent for adsorption of aflatoxins in nuts

In this study, a new fluorine-functionalized covalent organic framework (F-COF) was designed and fabricated by the direct polycondensation of tris(4-aminophenyl)amine and 2,3,5,6-tetra-fluoroterephthaldehyde for the first time. F-COF exhibited a remarkably enhanced adsorption capability compared with that of the fluorine-free COF. The favorable adsorption of aflatoxins was attributed to multiple interactions including pseudo hydrogen bond, F-O, π-π, F-π interactions and hydrophobic interactions between F-COF and aflatoxins. By coupling F-COF based solid phase extraction with high-performance liquid chromatography equipped with fluorescence detector, a rapid and sensitive method for determining aflatoxins (aflatoxin B1, B2, G1 and G2) in nuts (peanuts and pistachios) was established. Under optimal conditions (35 mg F-COF, 100 mL sample solution, 3 mL min-1 as sample loading rate, pH<7, 0.2 mL acetonitrile as desorption solvent), the limits of detection for aflatoxins were 0.02-0.30 ng g-1. The linear range was 0.08-16.0 ng g-1 and the recoveries of the F-COF-based method were 83.5-114 % with relative standard deviations less than 8.0 %.

Combined gestational age and serum fucose for early prediction of risk for bronchopulmonary dysplasia in premature infants

OBJECTIVE

As the predominant complication in preterm infants, Bronchopulmonary Dysplasia (BPD) necessitates accurate identification of infants at risk and expedited therapeutic interventions for an improved prognosis. This study evaluates the potential of Monosaccharide Composite (MC) enriched with environmental information from circulating glycans as a diagnostic biomarker for early-onset BPD, and, concurrently, appraises BPD risk in premature neonates.

MATERIALS AND METHODS

The study incorporated 234 neonates of ≤32 weeks gestational age. Clinical data and serum samples, collected one week post-birth, were meticulously assessed. The quantification of serum-free monosaccharides and their degraded counterparts was accomplished via High-performance Liquid Chromatography (HPLC). Logistic regression analysis facilitated the construction of models for early BPD diagnosis. The diagnostic potential of various monosaccharides for BPD was determined using Receiver Operating Characteristic (ROC) curves, integrating clinical data for enhanced diagnostic precision, and evaluated by the Area Under the Curve (AUC).

RESULTS

Among the 234 neonates deemed eligible, BPD development was noted in 68 (29.06%), with 70.59% mild (48/68) and 29.41% moderate-severe (20/68) cases. Multivariate analysis delineated several significant risk factors for BPD, including gestational age, birth weight, duration of both invasive mechanical and non-invasive ventilation, Patent Ductus Arteriosus (PDA), pregnancy-induced hypertension, and concentrations of two free monosaccharides (Glc-F and Man-F) and five degraded monosaccharides (Fuc-D, GalN-D, Glc-D, and Man-D). Notably, the concentrations of Glc-D and Fuc-D in the moderate-to-severe BPD group were significantly diminished relative to the mild BPD group. A potent predictive capability for BPD development was exhibited by the conjunction of gestational age and Fuc-D, with an AUC of 0.96.

CONCLUSION

A predictive model harnessing the power of gestational age and Fuc-D demonstrates promising efficacy in foretelling BPD development with high sensitivity (95.0%) and specificity (94.81%), potentially enabling timely intervention and improved neonatal outcomes.

Carbonized aerogel/ZnO-based dispersive solid phase extraction of daclatasvir and sofosbuvir from biological samples prior to liquid chromatography-tandem mass spectrometry

Daclatasvir and sofosbuvir are antiviral medications utilized in the treatment of chronic hepatitis C virus (HCV) infection. Due to their low therapeutic index, careful monitoring is necessary to ensure that the optimal dose is administered. High-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) is an exceptionally sensitive and specific technique for quantifying these drugs within biological matrices. In this study, we developed a novel dispersive solid-phase extraction method employing a carbonized bio aerogel composite with ZnO for efficient extraction of daclatasvir and sofosbuvir from exhaled breath condensate, urine, and plasma samples. The extracted analytes were subsequently subjected to analysis using HPLC-MS/MS. Optimal parameters including pH adjustment, sorbent quantity variation, and elution solvent selection were fine-tuned to achieve maximum recovery efficiency while ensuring selectivity enhancements. The developed method demonstrated broad linearity ranging between 1.2 and 200 ng/mL along with good precision (relative standard deviations ≤6.2 %) and an acceptable coefficient of determination (r2 ≥0.994). These findings establish our proposed method as suitable for reliable drug quantification in clinical samples.

Controllable synthesis of uniform flower-shaped covalent organic framework microspheres as absorbent for solid-phase extraction of trace 2,4-dichlorophenol

Controllable synthesis of micro-flower covalent organic frameworks (MFCOFs) with controllable size, monodisperse, spherical, and beautiful flower shape was realized by using 2,5-diformylfuran (DFF) and p-phenylenediamine (p-PDA) as building blocks at room temperature. High-quality MFCOFs (5 - 7 μm) were synthesized by controlling the kind of solvent, amounts of monomers, catalyst content, and reaction time. The synthesized MFCOFs possessed uniform mesopores deriving from the intrinsic pores of frameworks and wide-distributed pores belonging to the gap between the petals. The MFCOFs-packed solid-phase extraction (SPE) column shows adsorption capacity of about 8.85 mg g-1 for 2,4-dichlorophenol (2,4-DCP). The MFCOF-based SPE combined with the HPLC method was established for the determination of 2,4-DCP in environmental water. The linear range of this method is 20-1000 ng mL-1 (R2 > 0.9994), and limit of detection (S/N = 3) is 10.9 ng mL-1. Spiked recoveries were 94.3-98.5% with relative standard deviations lower than 2.3%.

Determination of alectinib and its active metabolite in plasma by pipette-tip solid-phase extraction using porous polydopamine graphene oxide adsorbent coupled with high-performance liquid chromatography-ultraviolet detection

Alectinib is known as an effective targeted drug, which has excellent therapeutic effect on non-small cell lung cancer and can significantly prolong the survival of patients. Therapeutic drug monitoring is necessary due to the photo-instability of alectinib and the individual differences in patients. In this work, a porous polydopamine graphene oxide composite (PDAG) was prepared by a simple surface modification method. A PDAG-based pipette-tip solid-phase extraction (PT-SPE) coupled with HPLC-UV detection was proposed for the separation and detection of alectinib and its active metabolite M4 in plasma. The method was methodologically validated and showed good linearity in the range of 50-5000 ng mL-1 (R2 > 0.9995). The limit of detection (LOD) was 4.8 ng mL-1 and 3.9 ng mL-1 for alectinib and M4, respectively, and the limit of quantitation (LOQ) was 16.1 ng mL-1 and 13.1 ng mL-1, respectively. The intra-day and inter-day precision expressed by coefficient of variation was less than 4.8 %. The recovery of this method ranged from 84.9 % to 103.5 % with a standard deviation of less than 4.3 %. In conclusion, the established method is accurate, stable and inexpensive, and can be used to monitor the levels of alectinib and M4 in plasma, which provide technical and data support for exploring optimal individualized remedial dosing regimens.

Application of high-performance liquid chromatography in determining saturates and aromatic hydrocarbons along with polars/additives in automotive finished and used lubricating oils

Lubricating oils help an internal combustion engine function effectively by reducing friction and wear on the engine's moving parts. They typically consist of petroleum-derived base oil and various additives to achieve the desired characteristics in automotive engine oils. Determination of aromatics and polar additives in the finished and used lubricating oils is not possible with existing methods hence their development is significant from the perspectives of environment and reuse/re-refining of used lubricating oils. This study reports the development of a new HPLC method to determine additives in the finished lubricating oils and/or polars in the used engine oils. The proposed method is simple, fast (runtime of 13 min), does not require sample pre-treatment, and exhibits high precision and superior limits of detection and quantification. The method demonstrated good linear response ranging from 0.1 to 30 mass for total aromatics and 0.1 to 20 % for additives. The method validation was carried out by analyzing brand-new commercial two and four-wheeler lubricants with used automotive lubricants. Based on the proposed method, the aromatics and additives concentration ranges in the studied finished lubricants were estimated between 0.20-1.70 % (mass) and 0.20-3.50 % (mass), respectively. Similarly, for used lubricants, the aromatics and additives were estimated to be 1.00-6.10 % and 0.60-2.40 % (mass), respectively.

Magnetic solid phase extraction coupled to HPLC-UV for highly sensitive analysis of mono-hydroxy polycyclic aromatic hydrocarbons in urine

BACKGROUND

As a common pollutant, the carcinogenic properties of polycyclic aromatic hydrocarbons have garnered considerable attention. Trace metabolites of polycyclic aromatic hydrocarbons can be detected in urine as a non-invasively approach to monitor the exposure level. Nonetheless, the urine samples have the disadvantages of being large in volume and containing numerous impurities. Given the growing demand to study metabolites with low abundance and potential biomarkers, there is a pressing need for a preconcentration and high-throughput technique for effectively handling complex liquid samples.

RESULTS

Polystyrene-coated magnetic nanoparticles were used to establish a novel magnetic extraction method for monohydroxy polycyclic aromatic hydrocarbons in urine samples. Polystyrene magnetic nanoparticles are an ideal absorbent for solid-phase extraction. After the material was mixed with the sample and adsorbed the target analyte, the analytes on the material were eluted and quantified using high-performance liquid chromatography. Influencing factors were optimized, and the proposed method achieved desirable sensitivity in analyzing low-abundance metabolites in large volumes of complex urine samples. The recoveries of intra-day and inter-day were 78.0-118.0 % and 81.0 %-115.0 %, respectively. The intra-day and inter-day reproducibility were less than 4.5 % and 8.6 %, respectively. The limits of detection were in the range of 0.009-0.041 ng mL-1, and the limits of quantification were in the range of 0.030-0.135 ng mL-1.

SIGNIFICANCE AND NOVELTY

The application of reusable polystyrene-coated magnetic solid-phase nanoparticles as adsorbents makes the extraction of monohydroxy polycyclic aromatic hydrocarbons from urine samples economical and environmentally benign. The proposed method is simple, sensitive, and efficient compared to existing techniques. The nanoparticles are easy to prepare, showing potential for rapid screening of complex bulk bio-samples in batches with high efficiency and low budget.

Quantifying the Kinetics of Pilus-Specific Sortase-Catalyzed Crosslinking Using High-Performance Liquid Chromatography

Gram-positive bacteria display pili whose protein components (pilins) are covalently crosslinked by pilus-specific sortase enzymes. These cysteine transpeptidase enzymes catalyze a transpeptidation reaction that joins the pilins together via lysine isopeptide bonds. The crosslinking reaction that builds the SpaA pilus in Corynebacterium diphtheriae is mediated by the SrtA sortase (CdSrtA) and has been reconstituted in vitro. Here, we present a protocol that can be used to measure the kinetics of CdSrtA-catalyzed crosslinking using high-performance liquid chromatography (HPLC). In principle, this biochemical procedure can be used to measure the in vitro crosslinking activity of any pilus-specific sortase.

Analysis of the Guanine Nucleotide-Bound State of KRAS by Ion-Pair Reversed-Phase High-Performance Liquid Chromatography

Guanine nucleotides can be quantitatively analyzed by high-performance liquid chromatography (HPLC). Here we describe an ion-pair reversed-phase HPLC (IP-RP-HPLC)-based method, which enables analyzing GDP and GTP bound to small GTPases immunoprecipitated from cells. The activation status of FLAG-KRAS expressed in HEK293T cells can be investigated with the IP-RP-HPLC method. This method also can be adapted to determine the effects of compounds such as the KRAS/G12C inhibitor sotorasib on the activation status of FLAG-KRAS in the cells.

Identification of Potential Insulinotropic Cytotoxins from Indian Cobra Snake Venom Using High-Resolution Mass Spectrometry and Analyzing Their Possible Interactions with Potassium Channel Receptors by In Silico Studies

Snake venoms are a potential source of bioactive peptides, which have multiple therapeutic properties in treating diseases such as diabetes, cancer, and neurological disorders. Among bioactive peptides, cytotoxins (CTXs) and neurotoxins are low molecular weight proteins belonging to the three-finger-fold toxins (3FTxs) family composed of two β sheets that are stabilized by four to five conserved disulfide bonds containing 58-72 amino acid residues. These are highly abundant in snake venom and are predicted to have insulinotropic activities. In this study, the CTXs were purified from Indian cobra snake venom using preparative HPLC and characterized using high-resolution mass spectrometry (HRMS) TOF-MS/MS. Further SDS-PAGE analysis confirmed the presence of low molecular weight cytotoxic proteins. The CTXs in fractions A and B exhibited dose-dependent insulinotropic activity from 0.001 to 10 µM using rat pancreatic beta-cell lines (RIN-5F) in the ELISA. Nateglinide and repaglinide are synthetic small-molecule drugs that control sugar levels in the blood in type 2 diabetes, which were used as a positive control in ELISA. Concluded that purified CTXs have insulinotropic activity, and there is a scope to use these proteins as small molecules to stimulate insulinotropic activities. At this stage, the focus is on the efficiency of the cytotoxins to induce insulin. Additional work is ongoing on animal models to see the extent of the beneficial effects and efficiency to cure diabetes using streptozotocin-induced models.

Quantification of Clofarabine and Fludarabine in Plasma by High-Performance Liquid Chromatography-Tandem Mass Spectrometry

Allogeneic hematopoietic cell transplantation (allo-HCT) is a potentially curative therapeutic treatment for many patients with high-risk hematologic malignancies and bone marrow failure syndromes. While allo-HCT can be highly effective, it is met with significant bone marrow conditioning regimen-related toxicities and complications such as infections related to poor immune reconstitution. This chapter describes the measurement of clofarabine and fludarabine concentrations to support clinical trials whose goal is to determine the optimal therapeutic ranges in order to maximize effectiveness while minimizing variability and regimen-related adverse events and toxicities. Moreover, the same holds true for patients receiving fludarabine as part of their lymphodepleting chemotherapy for chimeric antigen receptor T-cells (CAR T-cells). It is believed that one of the causes of variable outcomes after CAR T-cell therapy is lymphodepletion due to the variable fludarabine concentrations.This chapter describes a HPLC-MS/MS method to measure both compounds simultaneously. Clofarabine and fludarabine are extracted with solvent from plasma by the addition of deuterated internal standards prepared in methanol. Chromatographic separation is attained using a reversed-phase column followed by mass spectrometry which is performed in the positive ion mode. Herein, the described method to quantify both compounds in plasma is fast, accurate, and sensitive and allows for rapid drug concentration monitoring and timely dose adjustments.

Towards non-target proactive food safety: identification of active compounds in convenience tomato products by ten-dimensional hyphenation with integrated simulated gastrointestinal digestion

Current strategies for non-target food screening focus mainly on known hazardous chemicals (adulterants, residues, contaminants, packaging migrants, etc.) instead of bioactive constituents in general and exclude the biological effect detection. To widen the perspective, a more proactive non-target effect-directed strategy is introduced to complement food safety in order to detect not only known but also unknown bioactive compounds. The developed 10-dimensional hyphenation included on-surface digestion (1D), planar chromatographic separation (2D), visualization using white light (3D), UV light (4D), fluorescence light (5D), effect-directed assay analysis (6D), heart-cut zone elution to an orthogonal reversed phase column chromatography including online desalting (7D) with subsequent diode array detection (8D), high-resolution mass spectrometry (9D), and fragmentation (10D). Metabolism, i.e., intestinal digestion of each sample, was simulated and integrated on the same adsorbent surface to study any changes in the compound profiles. As proof of principle, nine convenience tomato products and a freshly prepared tomato soup were screened via five different planar assays in a non-targeted mode. Non-digested and digested samples were compared side by side. In their effect-directed profiles, 14 bioactive compounds from classes of lipids, plant hormones, spices, and pesticides were identified. In particular, bioactive compounds coming from the lipid class were increased by gastrointestinal digestion, while spices and pesticides remained unaffected. With regard to food safety, the determination of the two dinitrophenol herbicides dinoterb and dinoseb in highly processed tomato products should be given special attention. The hyphenation covered a broad analyte spectrum and showed robust and reliable results.

Chromatographic Separation and Quantitation of Sphingolipids from the Central Nervous System or Any Other Biological Tissue

Chromatographic separation and purification of an individual lipid to homogeneity have long been introduced. Using this concept, a more precise method has been developed to identify and characterize the sphingolipid composition(s) using a small amount (30 mg) of biological sample. Sphingolipids (lipids containing sphingosine or dihydrosphingosine) are well-known regulators of the central nervous system development and play a critical role in neurodegenerative diseases. Introducing a silicic acid column chromatography, sphingolipid components have been separated to individual fractions such as ceramide, glucosyl/galactosylceramide, other neutral and acidic glycosphingolipids, including (dihydro)sphingosine and psychosine; as well as phospholipids from which individual components are quantified employing a single or combination of other advanced chromatography procedures such as thin-layer chromatography, gas chromatography-mass spectrometry, and high-performance liquid chromatography-mass spectrometry.

Determination of Busulfan and Melphalan in Plasma by Turbulent Flow Chromatography-Tandem Mass Spectrometry

Melphalan and busulfan are DNA-alkylating agents that are often used concurrently in hematopoietic stem cell transplant (HCT) conditioning regimens. Studies have demonstrated that this combination of alkylating agents is very effective and well-tolerated prior to HCT. This combination is widely used for acute leukemia, advanced lymphoid malignancies, and multiple myeloma. Our goal was to develop an assay for the rapid measurement of both compounds simultaneously in the hopes that rapidly measuring their concentrations could possibly shorten the length of hospital stay. It would also simplify specimen handling in the clinic and the laboratory, reduce the amount of blood drawn, and allow for rapid reporting of the drug levels, thereby facilitating rapid dose adjustments.This chapter describes a validated method that measures both compounds simultaneously. Melphalan and busulfan were extracted from plasma with methanol containing deuterated internal standards. Turbulent flow chromatography coupled with reversed-phase HPLC was used for separation, while the mass spectrometer was set in the positive ion mode. This method has proven accurate and rapid and allowed for timely dose adjustments. The assay was linear over the clinically relevant ranges; the analytical measurement range for busulfan and melphalan was 10-5000 ng/mL and 10-15,000 ng/mL, respectively. Specimens containing elevated drug levels were diluted yielding a final clinically reportable range of 10-25,000 ng/mL for busulfan and 10-75,0000 ng/mL for melphalan. This method is very suitable for simultaneous measurements of these drugs and is currently being used to support pharmacokinetic studies.

Detectability of and interference by major and minor hemoglobin variants using a new-generation ion-exchange HPLC system with two switchable analysis modes

Objectives

High-performance liquid chromatography (HPLC) is commonly used to measure hemoglobin A1c (HbA1c) levels and detect hemoglobin variants (Hb-Vars). HLC-723GR01 (GR01) is a new-generation automated ion-exchange HPLC system with two switchable analysis modes, namely short (30 s/test) and long modes (50 s/test). We evaluated the general performance of both analysis modes of GR01 for quantifying HbA1c and detecting Hb-Vars.

Design and methods

We evaluated the instrument's precision based on CLSI protocol EP-05-A3. A comparison of the two analysis modes of GR01 against the standard mode of HLC-723G11 was performed on 100 whole blood samples. The GR01 long mode was compared with affinity HPLC (AF-HPLC) for detecting common Hb-Vars (HbE, HbD, HbS, and HbC, >20 samples). To examine the detection capability for minor Hb-Vars, we analyzed 26 Hb-Vars using multiple analyzers, including both analysis modes of GR01.

Results

Both modes of GR01 had within-laboratory coefficients of variation of ≤1.0 % from four samples with HbA1c concentrations of 32-86 mmol/mol. Good correlation was observed between GR01 and HLC-723G11. The results for HbA1c detection in the presence of the major variants revealed a strong correlation between the long mode of GR01 and AF-HPLC (r = 0.986-0.998), and the difference biases ranged 0.1-1.9 mmol/mol. In the long mode, only one variant had a difference bias exceeding 14 % [10 % (%NGSP)].

Conclusion

The two analysis modes of GR01 were fast and had high accuracy and reproducibility, indicating their utility for routine clinical use in measuring HbA1c samples with Hb-Vars.

The Process of Sterilizing Tattoo Inks Releases Formaldehyde

INTRODUCTION

Around 12% of Europeans and 20% of Americans have at least one tattoo. Tattoo inks, the substances used to create tattoos on the body, consist of chemicals that contain formaldehyde, which can be harmful to human health. The amount of formaldehyde present in commercially available tattoo inks and its causes are not well understood.

METHODS

We investigated the levels of formaldehyde in tattoo ink products sold in different countries and identified the factors contributing to its production. We also explored methods to reduce formaldehyde generation in tattoo inks. Seven tattoo inks from various brands were tested.

RESULTS

Formaldehyde release was predominantly associated with gamma radiation sterilization. Formaldehyde levels were observed to be higher in compositions containing organic components compared to those with inorganic components, irrespective of sterilization method and container type. Glycerin released over seven times more formaldehyde than other components during gamma-ray sterilization.

CONCLUSION

The results suggest that the presence of hydroxyl groups in carbon organic compounds in tattoo ink leads to photodegradation during gamma-ray radiation sterilization, resulting in increased concentrations of formaldehyde. Further research is needed to examine the chemical reactions occurring during sterilization processes and identify alternative sterilization methods that minimize formaldehyde formation. Additionally, the development of tattoo inks with reduced formaldehyde content and the establishment of strict quality control measures can help ensure the safety of tattooing practices.

Ultrasonic-microwave synergistic supramolecular solvent liquid-liquid microextraction of trace biogenic amines in fish and beer based on solidification of floating organic droplet

It is important to detect the presence of biogenic amines (BAs) as indicators of food freshness. The purpose of this study was to develop a novel ultrasonic-microwave synergistic supramolecular solvent liquid-liquid microextraction based on solidification of floating organic droplet (UMS-SUPRAS-SFO-LLME) combined with high-performance liquid chromatography for the determination of BAs. The physical properties and microstructure of SUPRAS based on 1-dodecanol and tetrahydrofuran were studied, and the extraction conditions such as the SUPRAS volume, the UMS process, and the centrifugal conditions were optimized. The results for the extraction kinetics and thermodynamics showed that UMS-SUPRAS-SFO-LLME is a spontaneous, endothermic diffusion process. The linear ranges of this method are 0.1-2.0 × 105 ng·mL-1 (R2 > 0.994), the limits of detection are 4.0 × 10-3-6.0 × 10-2 ng·mL-1, and the recoveries were 96.28-103.15%. Compared with existing analysis methods, UMS-SUPRAS-SFO-LLME is a sensitive, green and economical sample pretreatment method for analyzing the enrichment of BAs in beer and fish.

Synthesis of composite materials combining magnetic metal-organic frameworks and conjugated organic frameworks for selective extraction of carbendazim and thiabendazole residues from Chinese herbal medicine samples

A magnetic metal-organic framework MIL-68(Al) and a covalent organic framework were used as magnetic solid-phase extraction (MSPE) adsorbents in combination with high-performance liquid chromatography ultraviolet detection (HPLC-UV) to detect carbendazim (CBZ) and thiabendazole (TBZ). The main parameters affecting the extraction in the MSPE process were studied and optimized. Fe3O4@MIL-68(Al) coated with 1,3,5-tris(4-aminophenyl)benzene and terephthaldehyde (Fe3O4@MIL-68(Al)@TAPB-PDA-COF) was analyzed and verified. The material was proven to be suitable for adsorbing CBZ and TBZ. Various adsorption models were used to study its adsorption mechanism. The adsorption results were in good agreement with the pseudo-second-order kinetic model and Langmuir isotherm model. The maximum adsorption capacities of Fe3O4@MIL-68(Al)@TAPB-PDA-COF over CBZ and TBZ were 54.24 and 67.87 mg g-1, respectively, and the equilibrium adsorption time was 200 min. Fe3O4@MIL-68(Al)@TAPB-PDA-COF with excellent recyclability showed higher adsorption capacity and selectivity. A method based on Fe3O4@MIL-68(Al)@TAPB-PDA-COF combined with HPLC-UV was established under the optimal extraction conditions and used to separate and detect trace imidazole drugs in Chinese herbal samples, achieving a low limit of detection (0.65-1.30 μg L-1) with excellent linear correlation (r > 0.999). The recovery rate and relative standard deviation were 86.05-99.78 % and 0.15-4.90 %, respectively. Therefore, the Fe3O4@MIL-68@TAPB-PDA-COF can be regarded as an effective adsorbent for the pretreatment of CBZ and TBZ drugs in Chinese herbal samples.

Strat-M® positioning for skin permeation studies: A comparative study including EpiSkin® RHE, and human skin

In the development and optimization of dermatological products, In Vitro Permeation Testing (IVPT) is pivotal for controlled study of skin penetration. To enhance standardization and replicate human skin properties reconstructed human skin and synthetic membranes are explored as alternatives. Strat-M® is a membrane designed to mimic the multi-layered structure of human skin for IVPT. For instance, in Strat-M®, the steady-state fluxes (JSS) of resorcinol in formulations free of permeation enhancers were found to be 41 ± 5 µg/cm2·h for the aqueous solution, 42 ± 6 µg/cm2·h for the hydrogel, and 40 ± 6 µg/cm2·h for the oil-in-water emulsion. These results were closer to excised human skin (5 ± 3, 9 ± 2, 13 ± 6 µg/cm2·h) and surpassed the performance of EpiSkin® RHE (138 ± 5, 142 ± 6, and 162 ± 11 µg/cm2·h). While mass spectrometry and Raman microscopy demonstrated the qualitative molecular similarity of EpiSkin® RHE to human skin, it was the porous and hydrophobic polymer nature of Strat-M® that more faithfully reproduced the skin's diffusion-limiting barrier. Further validation through similarity factor analysis (∼80-85%) underscored Strat-M®'s significance as a reliable substitute for human skin, offering a promising approach to enhance realism and reproducibility in dermatological product development.

Functionalized carbon nanotube-polyaniline composite coating for on-line microextraction on a screw coupled with high performance liquid chromatography to determine opium alkaloids

A novel and efficient on-line microextraction on a screw coupled with high-performance liquid chromatography with an ultraviolet-visible detector was developed to extract and determine trace quantities of five opium alkaloids. All detections of the analytes were achieved at 210 nm. The surface of the screw grooves was electrochemically coated with the carbon nanotubes-COOH/polyaniline composite. The surface characterization was assessed by Fourier transform infrared spectroscopy and field emission scanning electron microscopy. The prepared screw was inserted into a cartridge of a guard column, and then the constructed microextraction on a screw device was placed in the loop of a six-port HPLC injection valve. The parameters affecting the extraction efficiency of the analytes were optimized using the one variable-at-a-time method. The effective parameters for the extraction efficiency of the analytes, including sample volume, extraction time, sampling flow rate, desorption solvent type, ionic strength, and pH were investigated and optimized. Under optimal conditions, the detection limits were 3-10 μg L-1, and the linear dynamic ranges were 10-2000 μg L-1 with a coefficient of determination greater than 0.9940. The inter-day and intra-day (n = 3) relative standard deviations were less than 7% and 5%, respectively. The proposed method was simple and reproducible, with an acceptable relative recovery (90-108%) for determining opium alkaloids in water and urine samples.

Ultrasound- and Vortex-Assisted Dispersive Liquid-Liquid Microextraction of Parabens from Personal Care Products and Urine, Followed by High-Performance Liquid Chromatography

Objectives

Parabens, which are p-hydroxybenzoic acid esters, are used as preservatives in personal care products, pharmaceuticals, and food because of their antimicrobial activity. However, they are also classified as suspected endocrine disruptors and carcinogens. In the present study, we aimed to optimize an ultrasound and vortex-assisted dispersive liquid-liquid microextraction (DLLME) procedure for the simultaneous extraction of methyl, ethyl, isopropyl, propyl, isobutyl, and butyl parabens from personal care products and urine.

Materials and Methods

The extraction solvent type, extraction solvent volume, disperser solvent volume, sodium chloride concentration, ultrasonication time, and vortex application time were evaluated to obtain optimum recoveries by ultrasound and vortex-assisted DLLME. Parabens were detected using a validated high performanc-liquid chromatography (HPLC) method with fluorescence detection. Method validation was performed by examining linearity, the limit of detection, limit of quantification, accuracy, and precision.

Results

The limits of detection and quantification of the HPLC method were between 0.09-0.18 μg/mL and 0.28-0.54 μg/mL, respectively. Precision was examined as the relative standard deviation, which was 0.22-1.81% and 1.12-2.03% for intra- and interday studies. Recovery percentages were higher than 96.00%. Samples of two paraben-free personal care products and synthetic urine were spiked with the analyses at 0.02 μg/mL and were successfully analyzed using the developed procedure with recovery values higher than 82.00%.

Conclusion

The proposed procedure provided quantification of selected parabens at 20 ng/mL in analyzed personal care products and urine matrices with good precision and accuracy.

Smartphone as a fluorescence detector for high-performance liquid chromatography

BACKGROUND

Fluorescence detection is employed in high-performance liquid chromatography (HPLC) due to its high specificity and sensitivity. However, it is often limited by expensive components and bulkiness. Recently, advances in technology and electronics have led to the development of smartphones that can serve as portable recording, analysis, and monitoring tools. Smartphone-based detection provides advantages of cost effectiveness, rapid signal/data processing, and the display of results on a handhold monitor. The combination of smartphone-based detection with HPLC can offer unique features that are beneficial in overcoming limitations of commercial fluorescence detectors. (90) RESULTS: A miniaturized and low-cost HPLC fluorescence detector based on a smartphone is introduced for the detection of six fluorescent molecules. The smartphone is able to capture emitted fluorescence in video format while MATLAB code is used for data processing to provide chromatograms based on different detection channels. A custom designed double-channel flow cell was utilized to enable simultaneous detection of fluorescent compounds with different excitation wavelengths. The detector consists of a lab-made flow cell, monochromatic LEDs as the light source, 3D printed housing and connector box, fiber optic cables, and a smartphone. The effects of flow cell geometry, channel width and light slit diameter, as well as a comparison of different flow cell manufacturing techniques, are studied and discussed. The validated system was successfully applied to samples from diverse water sources, yielding spiking recoveries within the range of 91.7% and 109.7%. (141) SIGNIFICANCE: This study introduces the first smartphone-based fluorescence detector for HPLC with cost-effective and customizable flow cells, allowing for the simultaneous detection of fluorescent compounds with different excitation wavelengths and offering a potential solution for the analysis of co-eluting compounds. Beyond its user-friendly interface and low-cost, smartphone detection in HPLC provides tremendous opportunities in further miniaturizing chromatographic instrumentation while offering high sensitivity and can be expanded to other mechanisms of detection. (70).

Preparation of a magnetic phosphazene-based hyper crosslinked polymer for the fast and efficient extraction of chlorophenols from water and peach juice

Two magnetic phosphazene-based hyper crosslinked polymers (M-HCP-OP-TMC and M-HCP-OP-TCL) were newly synthesized by the reaction of Friedel-Crafts acylation, and the M-HCP-OP-TMC showed an excellent extraction capability and rapid adsorption kinetics for chlorophenols as an adsorbent. Then, an efficient analytical method was built for the preconcentration and quantification of chlorophenols from water and peach juice samples by combining M-HCP-OP-TMC based magnetic solid-phase extraction (MSPE) with HPLC-UV detection. The linear response range for the chlorophenols by the method was 0.21-100.0 ng mL-1 for water sample, and 0.36-100.0 ng mL-1 for peach juice sample. The detection limits (S/N = 3) of the proposed method for the analytes were 0.07- 0.25 ng mL-1 and 0.12-0.45 ng mL-1 for water and peach juice samples, respectively. The method recoveries for the spiked samples were in the range of 93.1%-117.1%, and the relative standard deviations were less than 10%. The adsorption of the chlorophenols with the M-HCP-OP-TMC was mainly contributed by π-π stacking and hydrophobic interactions. The results indicate that the method was sensitive and accurate enough for the determination of the chlorophenols from real samples.

Comparison of HbA2 Using High Performance Liquid Chromatography Versus Haemoglobin Capillary Zone Electrophoresis

Thalassemia is among the most common hereditary disorders in the world. Approximately 5% of the world's population are carriers of hemoglobinopathies, and 2.9% are carriers of beta thalassemia. Haemoglobin A2 (HbA2) constitutes less than 3% of the total hemoglobin (Hb) in adults, and the determination of Hb A2 levels is important to diagnose the beta thalassemia trait (BTT). In some cases, the level of HbA2 is not typically elevated, and some difficulties may arise in making the diagnosis. Cation exchange high-performance liquid chromatography (HPLC) and HbCZE (haemoglobin capillary zone electrophoresis) are considered acceptable methods to diagnose BTT, but these vary in their accuracy and cut-offs. In this study, we attempted to compare HbA2 values using two methods, HPLC and HbCZE, in 536 whole blood samples sent by physician-ordered hemoglobinopathy screening over two years. This included antenatal women, patients with anemia not responding to iron, and cases of familial screening where either a child or a sibling had been diagnosed with hemoglobinopathy or thalassemia. The performance characteristics of both machines were compared for the detection of the 5 most common hemoglobin variants: Hb A, HbF, HbS, Hb C, and HbE. On comparing the HbA2 values, the HPLC showed higher values for HbA2 as compared to HbCZE, while the HbF and HbS measurement agreement was good between both methods. Normal ranges and mean normal values of HbA2 differ between different methods and different manufacturers; hence, each institute using these machines should validate its cutoffs.

Evaluating the bioequivalence of levetiracetam brand and generic oral tablets available in the Saudi market in vivo

Background

Epilepsy is a common global neurological disorder. About 30% of epileptic patients are managed with anti-epileptic Drugs (AEDs). Since 2000, Levetiracetam (LEV) has been marketed around the world as an AED under the brand name Keppra, and recently more generics are found in the Saudi market as cheaper alternatives. The objective of this study is to evaluate the bioequivalence of LEV brand and generics available in the Saudi market in mice.

Methods

Pharmacokinetics (PK), liver function test, and behavioral studies were conducted for LEV brand and generic in different groups of Blab/c mice.

Results

PK results show a significance difference in PK parameters mostly evidenced with generic 3, then generic 2. The only significant different between Keppra and generic 1 was in T1/2. In addition, Keppra did not significantly increase liver enzymes in comparison to other generics. On the other hand, other generics showed less favorable results in increasing liver enzymes. Keppra reduced the number and intensity of epileptic attacks, had no mortality rate due to epilepsy, and was associated with less sever seizures attacks.

Conclusion

Keppra, the brand form of LEV, has better safety and efficacy profiles in mice compared to 3 generics found in the Saudi market. Therefore, we recommend evaluating the same parameters tested in this study in patients utilizing similar generics and brand to establish the existence of bioequivalence between LEV brand and generics.

Biochar nanosphere-functionalized carbon fibers for in-tube solid-phase microextraction of polycyclic aromatic hydrocarbons in environmental water followed by liquid chromatography and diode array detection

In order to improve the extraction ability of carbon fibers (CFs) for microextraction of polycyclic aromatic hydrocarbons (PAHs), biochar nanospheres derived from glucose were in-situ grown onto the surface of CFs via hydrothermal synthesis. The surface morphology and elemental composition of biochar nanospheres-CFs were investigated by scanning electron microscopy and X-ray photoelectron spectroscopy. Thereafter, the biochar nanosphere-CFs were pulled into the polyetheretherketone tube for solid-phase microextraction, and the tube was combined with high-performance liquid chromatography-diode array detector to online detect PAHs. With the help of π-stacking, hydrophobic, and hydrophilic effect of biochar nanospheres, the extraction efficiency of CFs was greatly enhanced (enrichment factor increased by 293% compared with  the original). The conditions affecting the analytical performance (sampling volume, sampling rate, methanol content, and desorption time) were investigated. Under the optimal conditions, an online analytical method for microextraction and determination of several PAHs was developed, and satisfactory results were achieved. The limits of detection were 0.003-0.010 ng mL-1 owing to high enrichment effect (2973-3600), linearity ranged from  0.010-15.0 ng mL-1, and relative standard deviations were 0.4%-1.6% (intra-day) and 2.4%-4.4% (inter-day), respectively. The method was applied to analyze environmental water samples (rain water, snow water, and river water), and spiked recoveries within 80.0%-119% were obtained.

Pediatric reference intervals of the hemoglobin fractions HbA2, HbF and HbA0 using high-performance liquid chromatography and capillary electrophoresis

INTRODUCTION

β-thalassemia is a common genetic disorder with an estimated prevalence of 80-90 million carriers worldwide. As elevated hemoglobin A2 (HbA2) is a primary feature of carriers, hemoglobin fraction analysis is a common technique used for initial screening. However, pediatric reference intervals (RIs) are scarce. Hence, the aim was to establish pediatric RIs of hemoglobin fractions using high-performance liquid chromatography (HPLC) and capillary electrophoresis (CE).

METHODS

Samples were collected from assumed healthy children and adolescents of 1-18 years. Analyses were conducted using the Tosoh Automated Glycohemoglobin Analyzer HLC-723®G11 (Tosoh G11, HPLC) and the Capillarys 3 Octa (CE). Data were investigated for need of partitioning by both age (1-6 years vs. 6-18 years) and sex.

RESULTS

In total, 189 and 196 subjects were included in the statistical analysis of HPLC and CE, respectively. The 95% RI of HbA2 was 2.00-2.90% by HPLC and 2.2-3.0% by CE. Partitioning of data was not clinically relevant by HPLC. However, partitioning by age was suggested by CE.

CONCLUSION

RIs of hemoglobin fractions in individuals of 1-18 years using commercially available HPLC and CE equipment were reported. This is the first report of a pediatric RI of HbA2 using the Tosoh G11.

Modulation in the enzymatic antioxidants, MDA level and elicitation in conessine biomolecule in Holarrhena pubescens (medicinal tree) cultures exposed to different heavy metals: Ni, Co, Cr and As

Nodal explants of Holarrhena pubescens, an important medicinal tree, were cultured on Murashige and Skoog's medium (MS) containing 15 µM BA (control) alone and on medium supplemented with different concentrations (0, 1, 5, 25, 50, 100 and 200 mg/L) of heavy metals such as NiCl2, CoCl2, As2O3 and CrO3 to study their toxic effect. After 28 days of treatments, the nodal segments were harvested to assess the average number of shoots per explants, average shoot length, malondialdehyde content, proline content, conessine accumulation and antioxidant enzymatic activity. Among all the metals tried, best morphogenic response was achieved at 5 mg/L CrO3 where 80% culture differentiated an average of 3.21 ± 0.08 shoots per explant having 0.95 ± 0.018 cm average shoot length. Highest concentration (200 mg/L) of all the heavy metals proved lethal for morphogenesis. Maximum inhibition in average shoot number and average shoot length was observed in nodal explants treated with 25 mg/L As2O3 where an average of 0.49 ± 0.047 shoots having an average shoot length of 0.3 ± 0.02 cm. Contrarily, addition of heavy metals in culture medium proved strong elicitors, exhibiting significant enhancement in the biosynthesis of conessine, an important bioactive compound. HPLC analysis of the crude extract of in vitro grown untreated nodal cultures revealed an average of 117.06 ± 2.59 µg/g d. w. of conessine, whereas those treated with 100 mg/L of CoCl2 accounted for 297.1 ± 7.76 µg/g d. w. (an increase of 156% over control). Among the heavy metals tried, CoCl2 proved to be the best for conessine enhancement which was in the order of CoCl2 > Cr2O3 > NiCl2 > As2O3 in the nodal explants. Concomitantly, MDA content, the antioxidant enzymes activities of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GR) and ascorbate peroxidase (APX) were also observed to be differentially expressed with the increase in the heavy metals concentration from 1 to 200 mg/L. Free proline, too, increased up to 3.5-fold over control. The results obtained during the present investigation revealed that the overall response of the nodal explants in terms of morphogenesis, conessine content and antioxidant enzyme activities was metal specific as well as dose dependent.

Development and clinical application of a stability-indicating chromatography technique for the quantification of diazoxide

Diazoxide is a potential candidate for the treatment of transitional hypoglycaemia in infants. A clinical trial is currently underway to investigate whether low-dose oral diazoxide is beneficial for severe or recurrent transitional neonatal hypoglycaemia (the NeoGluCO Study, registration ANZCTR12620000129987). The present study aimed to develop and validate the parameters for quantifying diazoxide from neonatal plasma samples, and to assess the stability of extemporaneously prepared diazoxide suspensions to support the NeoGluCO Study. To determine the plasma concentration of diazoxide, a protein precipitation mediated extraction protocol was developed, which demonstrated >94% diazoxide extraction recoveries from all samples. The method was linear over the range of 0.2-40 μg/mL (R2 > 0.9994) with a limit of quantification of 0.2 μg/mL. Accuracy of the method was within 97-106% with relative standard deviation < 6% for all samples. Diazoxide-plasma samples were stable for up to three months at -20 °C and up to 48 h when stored in the auto-sampler. Samples were stable for up to two freeze-thaw cycles, with further cycles compromising stability of diazoxide in plasma. The developed method was applied to determine chemical stability of the extemporaneously prepared diazoxide suspensions. These were stable at both 2-8 °C and 25 °C/60% RH, with 98% of diazoxide remaining after 35 days in both storage conditions. Diazoxide was successfully quantified from plasma collected from six neonates enrolled in the NeoGluCO Study, using the developed protocol. Overall, an efficient and reproducible extraction protocol was developed and validated for the estimation of diazoxide from human plasma.

An effervescence-assisted switchable deep eutectic solvent based liquid-phase microextraction of triazole fungicides in drinking water and beverage

A new effervescence-assisted switchable deep eutectic solvent-based liquid phase microextraction (EA-SDES-LPME) combined with HPLC-UV was developed for determination of common triazole fungicides in drinking water and beverages, including myclobutanil, flusilazole, hexaconazole and bitertanol. The alternative extraction solvent was prepared with hexafluoroisopropanol and dipropylamine with the merits of time-saving, easy to collect and cost-effectiveness. The SDES can be reversibly switched between hydrophilic and hydrophobic states by pH adjustment. The homogeneous extraction was achieved under the hydrophilic form of SDES, and the bi-phase separation was obtained easily by adjusting pH value to restore the original hydrophobicity. Moreover, the characterization of SDES was investigated by FTIR and 1H NMR. The main variables affecting extraction efficiency were optimized in detail. Under the optimal conditions, the proposed method shows desirable precision (RSDs less than 18.5%) and acceptable recovery (72.6-95.4%). The lower limits of detection and limits of quantitation were found to be in the range of 1-2 μg L-1 and 5-10 μg L-1, respectively. The formation mechanism of SDES and the extraction mechanism for target analytes were investigated by density functional theory. The proposed methodology was simplicity, sensitive, time-saving and successfully applied to determine triazole fungicides in drinking water and beverages, making it an alternative technique for the analysis of trace analytes with satisfactory sensitivity.

In-pipette-tip kapok fiber-supported liquid extraction/in-situ derivatization coupled with high-performance liquid chromatography for conveniently determining three furfurals

This study presents an in-pipette-tip kapok fiber-supported liquid extraction/in-situ derivatization (in-pipette-tip KF-SLE-ISD) method for simultaneous enrichment and derivatization of furfurals. Briefly, 3 mg of natural kapok fiber, which was loaded in an assembled pipette-tip, was used to support 12.5 μL of extractant (ethyl acetate/toluene, 75:25, v/v) containing 10 mM 2,4-dinitrophenylhydrazine. The in-pipette-tip KF-SLE-ISD procedure was conveniently conducted by aspirating/releasing 1 mL of sample solution 10 cycles, allowing simultaneous extraction and derivatization of furfurals. Then, 100 μL of acetonitrile was aspirated/released 5 cycles for elution, 10 μL of which was directly analyzed by high-performance liquid chromatography. The limits of quantitation were in ranges of 0.10-0.45 μg/mL. The method showed satisfied linearity (R² > 0.99), precision (RSD < 8.53%) and relative recovery (90.34-114.71%), which was successfully applied to determine furfurals in various samples (e.g., honeys, juices and glucose injections). The proposed method has the merits of effectiveness, simplicity, low cost, wide availability and ease of automation.

Polyamidoamine with a hyper-branched structure grafted on modified magnetic graphene oxide for the trace separation of diclofenac and acetaminophen followed by high-performance liquid chromatography determination

Different generations of polyamidoamine dendrimers were synthesized on a focal core of magnetic graphene oxide modified with 3-aminopropyltriethoxysilane. After the characterization of synthesized dendrimers, its second generation was employed as a suitable sorbent for simultaneous separation/preconcentration of diclofenac and acetaminophen by a dispersive magnetic solid phase microextraction. The extracted analytes were then quantified by high-performance liquid chromatography with ultraviolet detection. Under optimized conditions, the limits of detection were 0.3 µg/L for diclofenac and 0.1 µg/L for acetaminophen. The intra-day relative standard deviations at 50 μg L-1 levels were 1.8% for diclofenac and 2.1% for acetaminophen, while the inter-day relative standard deviations were 3.6% and 4.5% for diclofenac and acetaminophen, respectively. The calibration graphs were linear in ranges of 1.0-500.0 µg/L and 0.5-600.0 µg/L for diclofenac and acetaminophen, respectively, with good coefficients of determination (r2 > 0.998). The method was successfully applied to the determination of diclofenac and acetaminophen in water, milk, and biological samples.

Magnetic deep eutectic solvent-based dispersive liquid-liquid microextraction for determination of strobilurin fungicides in water, juice, and vinegar by high-performance liquid chromatography

In this study, a magnetic deep eutectic solvent coupled with dispersive liquid-liquid microextraction using high-performance liquid chromatography (MDES-DLLME-HPLC) was developed to detect strobilurin fungicides. The green hydrophobic MDES synthesized by methyltrioctylammonium chloride, ferric chloride, and heptanoic acid was used as an extraction solvent, which was dispersed by vortex and separated by an external magnetic field. The use of toxic solvents was avoided, and the separation time was reduced. The best experimental results were obtained through single factor and response surface optimization. The method had a good linear relationship with R² > 0.996. The limit of detection (LOD) ranged from 0.001 to 0.002 mg L^-1. The extraction recoveries were 81.9-108.9%. The proposed method was rapid and green, and it has been successfully applied to detection of strobilurin fungicides in water, juice, and vinegar.

Improvement of analytical method for three azo dyes in processed milk and cheese using HPLC-PDA

This study aims to develop and validate a method for simultaneously measuring three azo dyes (azorubine, brilliant black BN, lithol rubine BK) not designated in Korea. The HPLC-PDA analysis method was validated based on the ICH guidelines, and the color stability was evaluated. The milk and cheese samples were spiked with azo dyes, the correlation coefficient of calibration curve ranged from 0.999 to 1.000 and the recovery rates of azo dyes were 98.81 ∼ 115.94%, with RSD of 0.08 ∼ 3.71%. The LOD and the LOQ in milk and cheese ranged from 1.14 to 1.73 μg/mL and 3.46 to 5.25 μg/mL, respectively. In addition, the expanded uncertainties of the measurements ranged from 3.3421 to 3.8146%. The azo dyes appeared to be color stable for more than 14 days. The results indicate that this analytical method is suitable for extracting and analyzing azo dyes in milk and cheese samples, which are not permitted in Korea.

Influence of geographic origin and tissue type on the medicinal chemical compounds of Semiliquidambar cathayensis

Semiliquidambar cathayensis is widely used in traditional Chinese medicine owing its high concentrations of polyphenol, triterpenoidic acid, and flavonoids. This study aimed to explore the impact of geographical origin and tissue type on the contents of chemical compounds of S. cathayensis, as determined by colorimetric and chromatographic methods. Therefore, we quantitively evaluated chemical compounds found in the tissues of various organs of plants collected in six different regions. Overall, we found that geographical origin affected the content of medicinal compounds in S. cathayensis leaves, with plants from Jingzhou county showing the best therapeutic potential. However, no specific correlation was observed with latitude. It is noteworthy that the amount of paeoniflorin and other compounds can be used as biomarkers of geographical origin and tissue type. Most medicinal compounds accumulated mainly in the leaves, whereas ursolic and oleanolic acids accumulated in the roots. These results show that the comprehensive medicinal value of the leaves of S. cathayensis in Jingzhou county is the highest, but the root should be selected first to collect oleanolic acid and ursolic acid.

A critical review of Roxadustat formulations, solid state studies, and analytical methodology

This review aims to collate information about the analytical methodologies, bioanalytical methodologies, pharmaceutical formulations, solid-state studies, and the current and future market scenario for a relatively new class of drugs, Roxadustat. Roxadustat is a hypoxia-inducible factor propyl hydroxylase inhibitor that significantly increases blood hemoglobin via the action of transcriptional activator HIF. As the molecule has a promising role in stimulating erythropoiesis, it is considered an ideal therapeutic agent for patients with anemia. In the current review, an attempt has been made to compile the pharmacological, pharmacokinetic, and pharmacodynamic characteristics of Roxadustat and systematically present product development data. This drug has several polymorphs of cocrystal, co-former, and salt, which have been explained in detail in the current work. The comprehensive review summarizes all the chromatographic methods and is presented in table form. This review has extensively covered Liquid chromatography-tandem mass spectrometry methods used to analyze Roxadustat in the biological matrix. The literature needs more data on forced degradation study, impurity profiling, gas chromatography, analytical methods for assay, dissolution, and different formulation aspects of Roxadustat.