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We established a method based on ultra performance liquid chromatography tandem mass spectrometry (UPLC‒MS/MS) to quantitatively measure tepotinib, which was validated as acceptable and used in the evaluation of food-drug interactions between tepotinib and naringenin in rats. We used pemigatinib as the internal standard (IS), and acetonitrile and 0.1% formic acid aqueous solution constituted the mobile phase. To extract the target analyte, acetonitrile was used for protein precipitation (PPT). For UPLC‒MS/MS, we performed liquid chromatography using a C18 column, and mass spectrometry was performed in positive multiple reaction monitoring (MRM) mode. Excellent linearity was shown in the range of 0.1–500 ng/mL, and the coefficient of correlation was > 0.99. Notably, the lower limit of quantification (LLOQ) for tepotinib was determined to be 0.1 ng/mL. The intra- and inter-day accuracy of tepotinib ranged from − 1.7 to 7.3%, while the precision was ≤ 8.4%, at three concentrations except LLOQ. The recovery of each substance was ≥ 81.2%, and the matrix effects were within 90.5-98.6%. The stabilities of all analytes under different conditions met all requirements for quantitation in plasma samples. The relevant parameters, such as LLOQ, were evaluated in accordance with the principles of the Food and Drug Administration (FDA) biological verification method. Food-drug interaction study had shown that the plasma concentration of tepotinib could be significantly increased, accompanied by a decrease in clearance rate when administered with 50 mg/kg naringenin. The results showed that naringenin could increase the plasma concentration and decrease the clearance rate of tepotinib when naringenin and tepotinib were administered at the same time. [ABSTRACT FROM AUTHOR]

UPLC-MS/MS analytical conditions for the analysis of aflatoxins in spices were optimized and validated in this study. Liquid-liquid partition-based protocols for the cleaning up of extracts using common organic solvents such as acetonitrile, hexane, and ethyl acetate were developed and validated. The developed liquid-liquid partition methods were compared with immuno-affinity column and QuEChERS clean-up methods for the UPLC-MS/MS analysis of aflatoxins in 8 spices. The reduction of lipophilic components using the partition with hexane is particularly useful in spices like red pepper that have higher levels of fatty acids, carotenoids, sterols, triterpenoids, etc. The subsequent partitioning with ethyl acetate considerably reduced the matrix interference from the polar components and increased the sensitivity. The cleaning up of spice extracts using liquid-liquid partition techniques resulted in limits of quantification (LOQ) of 2–5 µgL−1 in UPLC-MS/MS analysis. Trueness, repeatability, and reproducibility of the methods were in acceptable ranges. The accuracy of the developed methods was further verified by analyzing aflatoxins in naturally incurred samples of spices and comparing the results with those obtained from the immuno-affinity column cleanup-HPLC-FD method. [ABSTRACT FROM AUTHOR]

The limited data on the systematic evaluation and composition of metabolic compounds in different sorghum varieties makes their distinction difficult. Here, we employed untargeted metabolomic and multivariate statistical analyses on 129 sorghum samples collected from various regions across China using ultrahigh-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS). This approach enabled us to differentiate between two specific varieties of sorghum: Guizhou glutinous sorghum (GZGS), used in the production of soy sauce-flavoured baijiu in the Zunyi baijiu production area, and Guizhou Hongyingzi sorghum (GZ-HYZ), used in the production of Maotai-flavoured baijiu. The metabolic compounds in GZGS, mixed sorghum from other production areas, GZ-HYZ, and other glutinous sorghum varieties in Guizhou (GZ-others) were analysed, and key differential metabolites were identified. Differences were observed between the composition of GZ-HYZ and GZ-others. The phenylpropanoid biosynthesis pathway produced large amounts of flavonoids and lignins with antioxidant activity and phenols, which partially explained the formation of the Maotai liquor aroma. UPLC–MS/MS-based untargeted metabolomics can effectively reveal the differences in metabolites among sorghum varieties, thereby facilitating the authentication of GZGS and GZ-HYZ for brewing purposes. [ABSTRACT FROM AUTHOR]

Ectoine (ECT) has recently gained considerable interest in the healthcare sector due to its promising therapeutic benefits in a variety of human disorders. This research aimed to quantify the ECT plasma level in rats by creating and optimizing a sensitive and validated UPLC-MS/MS method. Prior to analysis, ECT extraction from the plasma samples was conducted via a protein precipitation procedure, using hydroxyectoine as an internal standard (IS). A 1.7 μm UPLC C8 column (100 mm × 2.1 mm) was selected for the chromatographic separation, using a gradient mobile phase consisting of acetonitrile and 0.05% formic acid. The electrospray ionization mass spectrometry (ESI-MS) was used to detect ECT in the positive ion mode. To determine the specific precursor and the product ions of ECT, multiple reaction monitoring (MRM) methods were carried out. The selected ion pair of ECT was 143.1 > 97 and 159.1 > 113.13 for the IS. The ECT's linearity range in rat plasma was found to be 1-1000 ng/mL, with a recovery rate of 96.48–97.37%. Consistent with FDA guidelines for bio-analytical method validation, the suggested method was validated. The method was efficiently employed to quantify the studied drug in spiked rat plasma with good accuracy and precision with no significant matrix effects. Furthermore, it was effectively used to investigate the pharmacokinetic behavior of ECT in rats after a single oral dose of 30 mg/kg. [ABSTRACT FROM AUTHOR]

Lupus nephritis (LN) is an immunoinflammatory glomerulonephritis associated with renal involvement in systemic lupus erythematosus (SLE). Given the close relationship between plasma amino acids (AAs) and renal function, this study aimed to elucidate the plasma AA profiles in LN patients and identify key AAs and diagnostic patterns that distinguish LN patients from those with SLE and healthy controls. Participants were categorized into three groups: normal controls (NC), SLE, and LN. Ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was employed to quantify AA levels in human plasma. Principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) were utilized to identify key AAs. The diagnostic capacity of the models was assessed using receiver operating characteristic (ROC) curve analysis and area under the ROC curve (AUC) values. Significant alterations in plasma AA profiles were observed in LN patients compared to the SLE and NC groups. The OPLS-DA model effectively separated LN patients from the SLE and NC groups. A joint model using histidine (His), lysine (Lys), and tryptophan (Trp) demonstrated exceptional diagnostic performance, achieving an AUC of 1.0 with 100% sensitivity, specificity, and accuracy in predicting LN. Another joint model comprising arginine (Arg), valine (Val), and Trp also exhibited robust predictive performance, with an AUC of 0.998, sensitivity of 93.80%, specificity of 100%, and accuracy of 95.78% in distinguishing between SLE and LN. The joint forecasting models showed excellent predictive capabilities in identifying LN and categorizing lupus disease status. This approach provides a novel perspective for the early identification, prevention, treatment, and management of LN based on variations in plasma AA levels. [ABSTRACT FROM AUTHOR]

Purpose: Intravenous narcotic agents, such as etomidate and metomidate, has been widely spread and abused in the world, including in Korea and China; thus, it is important to establish validated and sensitive analytical method for these compounds. Human hair as a biological sample has various advantages, including a wide detection window of drugs, compared to other typical samples, such as urine and blood in investigation. The purpose of this communication is to develop a reliable and useful method for the simultaneous detection and quantification of etomidate and metomidate in human hair samples by ultraperformance liquid chromatography combined with triple quadrupole mass spectrometry (UPLC–MS/MS), and to apply it for authentic samples in abuse cases. Methods: The hair samples were washed with a detergent solution, followed by with water and acetone. After drying, they were cut into approximately 2 mm sections and then ground to powder by a low-temperature grinder. The 20 mg of hair powder plus internal standard in 1 mL of methanol was vortexed and then centrifuged to obtain the supernatant layer, followed by subjecting to analysis. Results: The coefficient of determination (r2) values of the calibration curves of etomidate and metomidate in the hair samples were both more than 0.99 in the range of 1–500 ng/mg and 1–500 pg/mg, respectively. The limits of detection and lower limits of quantification were 0.5 and 1 pg/mg, respectively, for the both target compounds. Other tested validation data were all satisfactory. Etomidate and metomidate could be detected in the all hair samples and cigarette oil, which were seized by the police. The concentrations of etomidate and metomidate obtained from 10 samples from suspects were 5.48–45.7 ng/mg and 3.60–377 pg/mg, respectively. The concentrations of etomidate and metomidate in the cigarette oil were 95.8 μg/mg and 2.8 μg/mg, respectively. Conclusions: In this study, a simple and reliable analytical method for etomidate and metomidate in the human hair has been established. To the best of our knowledge, this is the first report to establish a method for the simultaneous detection and quantification of etomidate and metomidate in the human hair, and to apply it to authentic samples seized in authentic cases. [ABSTRACT FROM AUTHOR]

The aim of this work was to establish a cost-effective extraction procedure for simultaneous determination of pesticides and veterinary drugs in Chinese market preference fresh aquatic products based on MRLs in food of animal origin in China. Modified QuEChERS method coupled to UPLC-MS/MS for the simultaneous detection of 39 pesticides and veterinary drugs were developed. Six representative matrices of bulk fresh aquatic products in China's coastal markets showed applicability with recoveries 60.3–119.0% and acceptable precision 4.3–20.8%. Experiments showed that for fresh aquatic product matrices, the addition of EDTA-Mcllvaine effectively improved the extraction efficiency, and 0.4-g C18/0.4 g PSA/1.2-g MgSO4 combination with n-hexane extraction three times can remove the matrix interference effectively. Furthermore, LOD and LOQ in the range of 1.0–5.0 μg/kg and 3.0–10.0 μg/kg for 39 pesticides and veterinary drugs upon six representative matrices of bulk fresh aquatic products, respectively, that providing a practical flexible screening method for production quality control before entering the market. [ABSTRACT FROM AUTHOR]

In this study, we firstly established and verified a method by ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) for the analysis of vilazodone and its metabolite M10 in rat plasma, then this method was used to explore the pharmacokinetics of vilazodone and M10 present or absence of 80 mg/kg bergenin in rats. Protein precipitation with acetonitrile was used to prepare the samples in this research. The mobile phase for liquid chromatography was consisted of 0.1% formic acid aqueous solution and acetonitrile. Brexpiprazole was used as the internal standard (IS), and the multiple reaction monitoring (MRM) mode was used for detection. The verification items required by the US Food and Drug Administration (FDA) guidelines such as selectivity, sensitivity, linearity, stability, recovery and matrix effect of this method were all met the standards. Besides, rats were used to explore the drug-drug interaction between vilazodone and bergenin, which were divided into two groups, and separately gavaged with the same-volume of carboxymethyl cellulose sodium (CMC-Na) solution and 80 mg/kg bergenin, respectively. The results showed that bergenin significantly affected the metabolism of vilazodone. It suggested that there was a potential drug-drug interaction between bergenin and vilazodone in rats. In clinical application, we should pay attention to the dose of vilazodone when in combination with bergenin. [ABSTRACT FROM AUTHOR]

Wastewater-based epidemiology (WBE) has become an objective and updated surveillance strategy for monitoring and estimating consumption trends of psychoactive substances (PSs) in the population. Firstly, magnetic shrimp shell biochar-based adsorbent (DZMBC) was synthesized and employed for extraction trace PSs from municipal wastewater. Proper pyrolysis temperature and increased KOH activator content favored the pore structure and surface area, thus facilitating extraction. DZMBC delivered exceptional extraction performance such as pH stability, anti-interference property, fast magnetic separation ability, reusability, and reproducibility. Then, a method based on magnetic solid-phase extraction (MSPE) followed by ultra-high-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) was developed, validated, and utilized for the quantitative determination of five PSs in real wastewater samples. Methodological validation results indicated a favorable linearity, low method limits of detection (1.00–4.75 ng/L), and good precisions (intra-day and inter-day relative standard deviations < 4.8%). Finally, an objective snapshot of Chongqing drug use and consumption pattern was obtained. Methamphetamine (MAMP) and 3,4-methylenedioxymethamphetamine (MDMA) were the prevalent illegal drugs in local. Both concentrations and per capita consumption of MDMA displayed a change (P < 0.05) between July and September, while no statistical differences were observed for each week. [ABSTRACT FROM AUTHOR]

Broad-spectrum histone deacetylase inhibitors (HDACi) have excellent anti-tumor effects, such as abexinostat, which was a novel oral HDACi that was widely used in clinical treatment. The purpose of this study was to establish a rapid and reliable method for the detection of abexinostat concentrations in rat plasma using ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). The mobile phase we used was acetonitrile and 0.1% formic acid, and the internal standard (IS) was givinostat. Selective reaction monitoring (SRM) was used for detection with ion transitions at m/z 397.93 → 200.19 for abexinostat and m/z 422.01 → 186.11 for givinostat, respectively. The intra-day and inter-day precision of abexinostat were less than 11.5% and the intra-day and inter-day accuracy ranged from − 10.7% to 9.7% using this method. During the analysis process, the stability of the test sample was reliable. In addition, the recovery and matrix effects of this method were within acceptable limits. Finally, the method presented in this paper enabled accurate and quick determination of abexinostat levels in rat plasma from the pharmacokinetic study following gavage at a dose of 8.0 mg/kg abexinostat. [ABSTRACT FROM AUTHOR]

An effective analytical method using NTM-COFs on-line pass-through cleanup method and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) to simultaneously quantify 12 illicit drugs (norketamine, ketamine, codeine, cocaine, methamphetamine, 3,4-methylenedioxyamphetamine, 3,4-methylenedioxymethamphetamine, amphetamine, benzoylecgonine, 6-acetylmorphine, morphine and methadone) in hair sample was developed and validated. The hair sample was extracted with 0.3% formic acid-acetonitrile (v/v) and passed through the nano-titania-modified covalent organic frameworks (NTM-COFs) pre-column to reduce the matrix effect caused by hair specimen. Under the optimal conditions, satisfactory extraction efficiency was obtained for 12 illicit drugs with recoveries between 84.6% and 108.8%. The proposed method was linear for each analyte with correlation coefficients over 0.9926. The limits of detection and limits of quantification for 12 illicit drugs were in the range of 0.012–0.558 ng/g and 0.036–1.860 ng/g, respectively. Acceptable precision and accuracy were also achieved with relative standard deviations values below 9.92% and relative error values below 15.4%. The analytical method was successfully applied to real hair samples from suspected drug abusers, which was proved to be reliable and robust for drug screening in forensic toxicology. [ABSTRACT FROM AUTHOR]

Objective: This study sought to evaluate and validate a method for chemical composition analysis and content determination of Goupi plaster components, a conventional prescription preparation of traditional Chinese medicine. This is geared toward providing a basis for quality control research and future development of Goupi plaster. Methods: UPLC–Q-Exactive-MS was used to qualitatively analyze the chemical components of Goupi plaster from different manufacturers in positive and negative ion modes. UPLC–MS/MS method was used to establish the determination methods for the detection of sinomenine, osthole, and cinnamaldehyde in Goupi plaster from different manufacturers. Results: A total of 291 chemical components were identified in Goupi plaster from four manufacturers, including 97 chemical components with known source and pharmacological activity. Further, we determined the contents of sinomenine, osthole, and cinnamaldehyde. Conclusion: In summary, the UPLC–Q-Exactive-MS method was used to analyze the chemical components of Goupi plaster from different manufacturers. We established the UPLC–MS/MS method to determine the contents of sinomenine, osthole, and cinnamaldehyde in Goupi plaster from different manufacturers. The findings indicated that the method was comprehensive, rapid, and accurate, preliminarily revealing the material basis of Goupi plaster and providing a reference for follow-up development of Goupi plaster. [ABSTRACT FROM AUTHOR]

Alcohol abuse and addiction is a public health issue of global concern. Wastewater-based epidemiology (WBE) is a forceful and effective complementary tool for investigating chemical consumption. This study examined alcohol consumption in major cities of China via WBE and compared WBE estimates with other data sources. A simple and valid ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed for the determination of two alcohol metabolites, ethyl glucuronide (EtG) and ethyl sulfate (EtS) in wastewater. The optimized method was applied to 62 sewage samples collected from wastewater treatment plants (WWTPs) in 31 provincial capital cities across China in the fourth quarter of 2020. The methodology established in this study was validated with the lower limit of quantification (LLOQ) up to 0.1 μg/L, good linearity in the range of 0.1–50 μg/L, intra-day and inter-day precision less than 5.58% and 5.55%, respectively, and the recoveries of the extracts were higher than 97.14%. The consumption range of alcohol estimated via WBE was 6.09 ± 4.56 ethanol/person/day (EPD) in the capital cities of China. Alcohol consumption varies significantly between cities in China, with WBE estimating lower alcohol consumption than WHO and lower than foreign countries. Investing in alcohol consumption based on WBE has great potential to accurately and efficiently estimate alcohol consumption. [ABSTRACT FROM AUTHOR]

Emamectin benzoate (EB), chlorantraniliprole (CTP), chlorfenapyr (CFP), and lufenuron (LFR) are widely used to control Spodoptera exigua on cabbage. This study is aimed at establishing a universal, sensitive, accurate, and efficient method for the determination of these pesticide residues in cabbage using QuEChERS pretreatment combined with ultra-performance liquid chromatography or gas chromatography-tandem mass spectrometry (UPLC‒MS/MS or GC‒MS/MS). The recoveries of these pesticides (containing metabolites) in cabbage detected by the optimized method ranged between 80.9% and 99.9%, with relative standard deviations (RSDs) of 0.164–12.5%. The limit of quantification (LOQ) of the four pesticides was determined to be 0.01 mg/kg. The standard curve, accuracy, precision, and LOQ of the analysis method all met the requirements of pesticide residue detection. The optimized method was used to detect the dissipation dynamics and terminal residues in 12 regions. The dissipation half-lives of CTP, CFP, and LFR were 3.35–7.01 d, 2.29–4.75 d, and 3.24–6.80 d, respectively. The terminal residues of all these pesticides were below the maximum residue limits (MRLs). The dietary risk assessment indicated that the dietary risk probabilities for EB, CTP, CFP, and LFR were all less than 1 and were within the acceptable range. This study provides a comprehensive assessment of the residues and dietary risks of EB, CTP, CFP, and LFR for the scientific use of pesticides. [ABSTRACT FROM AUTHOR]

The lack of standard substances is a bottleneck for quality control in natural plants. In this study, a novel and accurate method for the determination of four gingerol components in ginger extracts was developed and validated by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) combined with a single marker (ASM) using a new calculation of relative response factor (nRRF, fox). The contents of four analytes in ginger extracts were determined by the single marker of nonivamide used as the internal reference which did not exist in the sample and was similar to gingerol in structure and performance. The four analytes showed a good linear relationship within a certain concentration range, and the correlation coefficients (R) were all greater than 0.999. The LOD and LOQ obtained for each standard were 2.14–5.50 ng/mL and 7.15–18.35 ng/mL, respectively. The average recoveries at three spiked levels ranged from 89.53 to 100.01% for ginger extract samples with relative standard deviations of 1.03 to 3.61%. The method was evaluated by a comparison of the quantitative results between the external standard method (ESM) and ASM. The results showed that no significant differences were found in the quantitative results of the four contents of essential oil extract of ginger from three different extraction methods determined by ESM and ASM. The sum contents of four analytes were highest in the sample obtained from subcritical extraction method. The proposed approach could serve as an accurate and convenient method in determining the gingerol components in the ginger extracts and its processed products. [ABSTRACT FROM AUTHOR]

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants. Studying the bioaccumulation in mammalian tissues requires a considerable effort for the PFAS extraction from complex biological matrices. The aim of the current work was to select and optimize the most efficient among common extraction strategies for eleven perfluoroalkyl acids (PFAA). Primary extractions from wild boar tissues (liver, kidney, and lung) were performed with methanol at neutral, acidic, or alkaline conditions, or with methyl-tert-butyl ether (MTBE) after ion-pairing with tetrabutylammonium (TBA) ions. A second purification step was chosen after comparing different solid-phase extraction (SPE) cartridges (Oasis WAX, ENVI-Carb, HybridSPE Phospholipid) and various combinations thereof or dispersive SPE with C18 and ENVI-Carb material. The best extraction efficiencies of the liquid PFAA extraction from tissue homogenates were achieved with methanol alone (recoveries from liver 86.6–114.4%). Further purification of the methanolic extracts using dispersive SPE or Oasis WAX columns decreased recoveries of most PFAA, whereas using pairs of two SPE columns connected in series proved to be more efficient albeit laborious. Highest recoveries for ten out of eleven PFAA were achieved using ENVI-Carb columns (80.3–110.6%). In summary, the simplest extraction methods using methanol and ENVI-Carb columns were also the most efficient. The technique was validated and applied in a proof of principle analysis in human tissue samples. [ABSTRACT FROM AUTHOR]

Ankylosing spondylitis (AS) is an autoimmune rheumatic disease that mostly affects the axial skeleton. This study aimed to investigate reliable diagnostic serum biomarkers for AS. Serum samples were collected from 20 AS patients and 20 healthy controls (HCs) and analyzed using ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS). The differential metabolites between the AS patients and HCs were profiled using univariate and multivariate statistical analyses. Pathway analysis and a heat map were also conducted. Random forest (RF) analysis and the least absolute shrinkage and selection operator (LASSO) were used to establish predictive and diagnostic models. After controlling the variable importance in the projection (VIP) value > 1 and false discovery rate (FDR) < 0.05, a total of 61 differential metabolites were identified from 995 metabolites, which exhibited significant differences in the pathway analysis and heat map between the AS patients and HCs. RF as a predictive model also identified differential metabolites with 95% predictive accuracy and a high area under the curve (AUC) of 1. A diagnostic model comprising nine metabolites (cysteinylglycine disulfide, choline, N6, N6, N6-trimethyllysine, histidine, sphingosine, fibrinopeptide A, glycerol 3-phosphate, 1-linoleoyl-GPA (18:2), and fibrinopeptide A (3–16)) was generated using LASSO regression, capable of distinguishing HCs from AS with a high AUC of 1. Our results indicated that the UPLC–MS/MS analysis method is a powerful tool for identifying AS metabolite profiles. We developed a nine-metabolites-based model serving as a diagnostic tool to separate AS patients from HCs, and the identified diagnostic biomarkers appeared to have a diagnostic value for AS. [ABSTRACT FROM AUTHOR]

The use of contaminated raw materials can lead to the transfer of mycotoxins into the final product, including beer. This study describes the use of the commercially available immunoaffinity column 11+Myco MS-PREP® and UPLC-MS/MS for the determination of mycotoxins in pale lager-type beers brewed in Czech Republic and other European countries. The additional aim of the work was to develop, optimize and validate this analytical method. Validation parameters such as linearity, limit of detection (LOD), limit of quantification (LOQ), precision and accuracy were tested. The calibration curves were linear with correlation coefficients (R2 > 0.99) for all mycotoxins under investigation. The LOD ranged from 0.1 to 50 ng/L and LOQ from 0.4 to 167 ng/L. Recoveries of the selected analytes ranged from 72.2 to 101.1%, and the relative standard deviation under conditions repeatability (RSDr) did not exceed 16.3% for any mycotoxin. The validated procedure was successfully applied for the analysis of mycotoxins in a total of 89 beers from the retail network. The results were also processed using advanced chemometric techniques and compared with similar published studies. The toxicological impact was taken into account. [ABSTRACT FROM AUTHOR]

Antibiotics are among the most common medicine groups since they are used to treat infectious diseases, as nutritional supplements in livestock breeding, and for preservation in the food industry. Turkey is among the highest antibiotic consumers in the world. In the present study, the most popular 14 antibiotics available in Turkey were monitored in one hospital sewage and two urban wastewater treatment plant influents and effluents seasonally in Istanbul province, the largest metropolitan center in Turkey. The present research aimed to develop a robust analytical method to determine 14 antibiotics, including six chemical groups, in environmental matrices which are considered significant antibiotic pollution sources, namely hospital sewage and urban wastewater. Solid-phase extraction (SPE) and UPLC-MS/MS analysis parameters included optimized column temperature, eluent, mobile phase, and flow rate. Three SPE cartridges were employed in recovery studies. The antibiotic recovery rates varied between 40 and 100%, and all analytes were identified within 3 min with UPLC-MS/MS under optimal conditions. It was determined that method detection limits (MDLs) varied between 0.07 and 2.72 µg/L for the antibiotics. In all seasons, the highest beta-lactam group antibiotic concentrations were identified in hospital sewage. The season with the greatest variety of antibiotics in urban wastewater was spring. Clarithromycin and ciprofloxacin were the antibiotics determined at the highest concentration in the influent and effluent of the wastewater treatment plant in all seasons. This study showed that the most widely used beta-lactam group antibiotics were found in high amounts in hospital sewage wastewater but in low concentrations in the treatment plants, and hence, it is seen that the degradability of beta-lactam group antibiotics was high. The presence of clarithromycin, ciprofloxacin, lincomycin, levofloxacin, and trimethoprim antibiotics in hospital sewage in higher amounts and also in inlet and outlet of wastewater treatment plants proves that those are resistant antibiotics. [ABSTRACT FROM AUTHOR]

The presence of Bisphenol A (BPA), Bisphenol A Diglycidyl Ether (BADGE), and their derivatives in seventy-nine samples of food products available in Turkish stores was determined using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Among Bisphenol A and its analogues, BPA was the most detected migrant with 56.97%. Fish products had the highest level of BPA with 0.102 mg/kg although only three fish samples exceeded the Specific Migration Limit (SML) for BPA of 0.05 mg/kg of food. The BPF, BPS, and BPB in all analyzed foods ranged between 0–0.021, 0–0.036, and 0.072 mg/kg, respectively. BADGE derivates, BADGE·2H2O and cyclo-di-BADGE (CdB) were present in 57 and 52 samples with concentrations ranging between 0–0.354, and 0–1.056 mg/kg, respectively. All the analyzed traditional Turkish ready-to-eat meals and fish products were contaminated with BADGE·2H2O and CdB. The overall levels of BADGE and the derivates were below the specific migration limit. CdB was found at higher concentrations in traditional Turkish ready-to-eat meals, up to 1.056 mg/kg. The CdB concentration in most of the samples was above the highest figure with 0.05 mg/kg authorized by the German Federal Institute for Risk Assessment. The predominant chlorinated derivative was BADGE·H2O·HCl which was found in thirty-seven samples in the range of 0.007–0.061 mg/kg. [ABSTRACT FROM AUTHOR]

Introduction: Osteonecrosis of the femoral head (ONFH) is a disorder that causes a collapse of the femoral head, requiring subsequent total hip replacement. However, the pathogenesis of ONFH remains largely unclear. Herein, exosome metabolomics analyses were conducted to explore the pathophysiology of ONFH. Objectives: This study aimed to conduct metabolic profiling of bone-derived exosomes of ONFH. Methods: 30 ONFH patients and 30 femoral neck fracture (FNF) patients were included in this study. Exosomes were harvested from the femoral head by using ultracentrifugation. Ultraperformance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) was performed in combination with multivariate statistical analysis to reveal and provided new insight into identify the global metabolic profile of ONFH. Results: The results of transmission electron microscope (TEM), nanoparticle tracking analysis (NTA), and Western blots indicated that the microvesicles isolated from the femoral head were exosomes. Several compounds were identified, including lipids and lipid-like molecules, amino acids, peptides, organooxygen compounds. 44 differential metabolites were screened between ONFH and FNF patients. The up-and down-regulation of Riboflavin metabolism, Pantothenate and CoA biosynthesis, Glycerophospholipid metabolism, and Sphingolipid metabolism were associated with ONFH pathophysiology. Conclusion: Our results suggest that metabolomics has huge prospects for elucidating pathophysiology of ONFH. [ABSTRACT FROM AUTHOR]

Harmful algal blooms is a widespread problem in aquatic ecosystems, in particular dinoflagellates that produce PSTs which are harmful to animal and human health. To explore the contamination status of PSTs in shellfish in the Southeastern China, a total of 2355 shellfish samples were analyzed by ultra high-performance liquid chromatography–tandem mass spectrometry (UPLC-MS/MS) to study the toxin profiles of the 10 PSTs collected from the southeast coast of China from 2017 to 2021. From 2355 shellfish samples, 257 were detected (10.91%), with the highest value in samples of Perna viridis. Among the six source areas in China, the samples from Fujian recorded the highest detected rate (15.28%). PSTs were found in Fuzhou, Ningde, Quanzhou, Putian, Zhangzhou, and Xiamen, with Quanzhou and Fuzhou having the highest and lowest detection rates of 15.28% and 4.23%, respectively. Saxitoxin (STX), neosaxitoxin (neoSTX), gonyautoxin (GTX1, GTX2, GTX3, GTX4), N-sulfocarbamoyl toxin (GTX5), and decarbamoyl toxin (dcSTX, dcGTX2, dcGTX3) were detected, and GTX5 and dcGTX2 were dominant. In addition, the samples containing PSTs were mostly concentrated in May to August. The study confirms the risks of PSTs to shellfish consumers in the region. It will offer a great foundation for future monitoring of marine toxins and protecting the health of seafood consumers in China. This is the first detailed evaluation of PSTs occurrences and their profiles in shellfish from the Southeastern China over a period of multiple years. Highlights: 2355 mussels from China were analyzed by UPLC-MS/MS for PSTs in 2017–2021. The predominant PSTs were GTX5, neoSTX and dcGTX2. Arca granosa and Crassostyea gigas exhibited higher levels than other shellfish. Shellfish containing PSTs were mostly concentrated in May to August. Maximum detected level in shellfish was 2137.10 ug STXeq/kg. [ABSTRACT FROM AUTHOR]

Analytical method for three natural estrogens (NEs) and their sulfate and glucuronide conjugates in waste and river waters using solid-phase extraction (SPE) coupled with ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) has been available, but problems including poor recovery exist. In order to solve these, some optimizations have been performed in this work. For sample preparation, both rinse and elution solutions were optimized, in which 6 mL of MeOH/water (1:9, v/v), MeOH/Ace/water (10:2:88, v/v/v), and MeOH/NH4OH/water (10:2:88, v/v/v) were determined as the rinse solution, while 6 mL of 2.0% NH4OH/MeOH was determined as the elution solution for conjugated NEs (C-NEs). For mobile phase, addition of NH4F could obviously enhance the signal response of the nine target compounds, and the optimized addition concentration was 0.5 mmol/L. The developed efficient method was validated and showed excellent linearity for each target compound (R2 > 0.998), low limit of quantifications (LOQs, 0.07–1.29 ng/L) in four different water matrices, and excellent recovery efficiencies of 81.0–116.1% in influent, effluent, ultra-pure, and river water samples with low relative standard deviations (RSDs, 0.6–13.6%). The optimized method was successfully applied to influent, effluent, and Pearl River water, among which three NEs were all detected, while five C-NEs were found in the influent, three C-NEs were detected in the effluent, and two C-NEs were found in the Pearl River water, indicating the wide distribution of NEs and C-NEs in different water environments. This work provided a reliable and efficient analytical method for simultaneous trace determination of NEs and C-NEs, which had satisfactory absolute recoveries with low RSDs, low LOQs, and time-saving for both analysis and nitrogen drying. [ABSTRACT FROM AUTHOR]

To promote the quality control of midazolam and ensure the life safety of patients, a sensitive and simple ultra-high performance liquid chromatography–mass spectrometry (UPLC–MS/MS) method was developed for the trace determination of two potential genotoxic impurities (PGIs) in midazolam raw materials under the positive electrospray ionization (ESI) mode with multiple reaction monitoring (MRM). The two PGIs were well separated in a gradient elution mode at a 0.4 mL/min flow rate on an ACQUITY UPLC BEH C18 column (2.1 mm × 100 mm, 1.7 µm) that was maintained at 40 °C. 0.01 mol/L ammonium formate aqueous solution (0.1% formic acid) and acetonitrile (0.1% formic acid) were mobile phase A and mobile phase B, respectively. The m/z of 343.00/123.00 for PGI-1and m/z of 331.20/301.20 for PGI-2 were detected in a triple quadrupole mass detector. The calibration curves showed that the two PGIs have good linearity between the concentration range of 0.004 and 0.8 ppm. The correlation coefficients of PGI-1 and PGI-2 were 0.9996 and 0.9998, respectively. The recoveries of the two PGIs at three concentration levels were in the range of 81–103%. The limits of quantification (LOQ) for PGI-1 and PGI-2 were 0.0545 and 0.0111 ng/mL respectively. The precision relative standard deviation (RSD) of each impurity was observed less than 3.0%. Method validation results indicated that the linearity, accuracy, precision, and sensitivity of the developed UPLC–MS/MS method are satisfactory. Thus, the method can quantitatively detect the two trace PGIs in midazolam. This study can provide a reference for manufacturers and relevant researchers of midazolam, reduce the quality risk of midazolam drugs and ensure the safety of patients. [ABSTRACT FROM AUTHOR]

Summary: Neratinib, an irreversible pan-HER tyrosine kinase inhibitor, has been approved for the treatment of HER2-positive (HER2+) early-stage and brain metastatic breast cancer. Thus far, the pharmacology effects and pharmacodynamics of neratinib have been well studied. However, the disposition of neratinib and its influencing factors in vivo remain unclear. P-glycoprotein (P-gp), one of the most extensively studied transporters, substantially restricts penetration of drugs into the body or deeper compartments (i.e., blood-brain barrier, BBB), regarding drug resistance and drug-drug interactions. Thereby, the aim of this study was to investigate the influence of verapamil (a P-gp inhibitor) on the pharmacokinetics of neratinib in rats. Here, we have established a high specific, selective and sensitive ultra-performance liquid chromatography-tandem mass spectrometric (UPLC-MS/MS) method to quantify plasma concentrations of neratinib in rats. Pharmacokinetic results showed that verapamil significantly increased the system exposure of neratinib, as Cmax increased by 2.09-fold and AUC0-t increased by 1.64-fold, respectively. Additionally, the in vitro transport of neratinib was evaluated using Madin-Darby canine kidney II (MDCK II) and human MDR1 gene overexpressed MDCK (MDCK-MDR1) cell line models. As a result, the net flux ratio was over than 2 and decreased over 50% by verapamil, suggesting that neratinib was a substrate of P-gp. Hence, our findings have highlighted the important role of P-gp in the system exposure of neratinib in vivo, and drug-drug interaction should be considered when coadministration of P-gp inhibitors with neratinib. These findings may support the further clinical development and application of neratinib. [ABSTRACT FROM AUTHOR]

In view of the significance of food safety and the possible relationship between residual enrichment and acute toxicity for pesticides in different aquatic organisms, it is essential to establish a sensitive and reliable determination method for pesticides in different aquatic organisms to analyze the enrichment levels. Quinone outside inhibitor fungicides (QoIs) are lipophilic fungicides that pose environmental threats to aquatic organisms. Previous research has mainly focused on QoI residues in aquatic organisms under chronic toxicity, whereas less is known about how pesticide residues differ among aquatic organism under acutely toxic conditions. In the present study, the residues of QoIs in aquatic organisms (Danio rerio, Rana pipiens, Cherax quadricarinatus, Misgurnus anguillicaudatus, Corbicula fluminea, and Ampullaria gigas) were analyzed by ultrahigh-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) coupled with a proposed QuEChERS method. The proposed method was validated in terms of linearity (coefficients of determination of 0.9980–0.9999), the limits of quantification (0.01 μg·kg−1), the relative standard deviation (0.6–4.4%), and recovery (70.12–118.15%). The results demonstrated that the proposed method fulfilled the requirements for pesticide analysis in all tested aquatic organisms. The residues of QoIs in the same aquatic organism exposed to QoI concentrations of 5 and 500 μg L−1 decreased in the order pyraoxystrobin > pyraclostrobin > triclopyricarb > picoxystrobin > azoxystrobin > fluoxastrobin. Furthermore, the acute toxicity was strongly correlated with the enrichment level of the QoIs in aquatic organisms. This study provides the first documentation of a correlation between the enrichment level of QoIs and acute toxicity in aquatic organisms, which provides a basis for the management of agrochemicals considering aquatic ecological risks. [ABSTRACT FROM AUTHOR]

Amino acids (AAs) are important nitrogen-containing organics in water, and a large number of reports have proven that they were the precursors of many nitrogen-containing disinfection by-products, some of which have cytotoxicity and carcinogenicity. However, little has been done on their occurrence in drinking source water. Therefore, a trace determination method via solid-phase extraction coupled with ultra-high pressure liquid chromatography tandem mass spectrometry (UPLC-MS/MS) for 15 free AAs (FAAs) was developed, which was successfully applied for drinking source water samples. For sample preparation, strong cation-exchange stationary solid-phase extraction (SPE) cartridge showed better extraction performance to that of reverse phase stationary oasis HLB SPE cartridge. The optimal water pH was determined to be 2.8 before extraction. Strong matrix effects for most FAAs were observed in this work; thus, sample extraction with SPE was recommended to eliminate the matrix effects. The developed method showed excellent linearity (R2 > 0.991), low limits of detection (LODs, 0.01–0.27 nmol/L), and good recoveries of 69.8–117.9% in drinking source water with low relative standard deviations (RSDs, 0.3–13.2%). The developed method was finally applied to eight drinking source water samples, and the top five FAAs were found to be serine, glycine, leucine, alanine, and isoleucine. [ABSTRACT FROM AUTHOR]

Sinomenine is a bioactive alkaloid isolated from the Chinese medicinal plant Sinomenium acutum (Thunb.) Rehd. et Wils which exhibits significant analgesic, anti-inflammatory, and immunosuppressive effects. Sinomenine hydrochloride (SH) preparations, classified as natural disease-modifying antirheumatic drugs, are currently available for the treatment of rheumatoid arthritis and other rheumatic diseases. Our toxicity evaluation demonstrated that the median lethal dose of SH in female Sprague-Dawley (SD) rats was over 11 times greater than that in male SD rats, revealing striking sex-linked differences in the safety profile of SH. The present study was designed to investigate differences in the pharmacokinetics (PKs) and tissue distribution of SH between male and female SD rats after a single oral dose of 25 mg/kg. PK and tissue distribution studies were performed using a validated UPLC-MS/MS method. The results showed that SH-treated SD female rats displayed markedly greater drug exposure, and SH exhibited a longer half-life and slower clearance rate than comparable studies in male rats. Moreover, the tissue distribution study confirmed that the sinomenine concentration in female rats was considerably greater in the internal organs than in male rats. Our study demonstrates, for the first time, significant sex-related differences in the safety profile and PKs of SH, which may be associated with a distinct sex-dependent metabolic mechanism of sinomenine. [ABSTRACT FROM AUTHOR]

This work explores the degradation of xenobiotic compounds in aerobic and anaerobic batch reactors. Different inoculums were spiked with nine emerging contaminants at nominal concentrations ranging between 1 to 2 mg/L (ibuprofen, diclofenac, naproxen, acesulfame, sucralose, aspartame, cyclamate, linear alkylbenzene sulfonates, and secondary alkyl sulfonates). Ethanol was used as co-substrate in the anaerobic reactors. We found that the kinetic decay was faster in the aerobic reactors inoculated with a Spanish (Spn) inoculum compared to a Brazilian (Brz) inoculum, resulting in rection rates for LAS and SAS of 2.67 ± 3.6 h−1 and 5.09 ± 6 h−1 for the Brz reactors, and 1.3 ± 0.1 h−1 and 1.5 ± 0.2 h−1 for the Spn reactors, respectively. There was no evidence of LAS and SAS degradation under anaerobic conditions within 72 days; nonetheless, under aerobic conditions, these surfactants were removed by both the Brz and Spn inoculums (up to 86.2 ± 9.4% and 74.3 ± 0.7%, respectively) within 10 days. The artificial sweeteners were not removed under aerobic conditions, whereas we could observe a steady decrease in the anaerobic reactors containing the Spn inoculum. Ethanol aided in the degradation of surfactants in anaerobic environments. Proteiniphilum, Paraclostridium, Arcobacter, Proteiniclasticum, Acinetobacter, Roseomonas, Aquamicrobium, Moheibacter, Leucobacter, Synergistes, Cyanobacteria, Serratia, and Desulfobulbus were the main microorganisms identified in this study. [ABSTRACT FROM AUTHOR]

As a major class of phenolic compounds, anthocyanins are the functional components of blueberry. Vaccinium corymbosum 'Lanmei 1' is a novel blueberry variety and detailed study of their anthocyanins remains scarce. Therefore, a simultaneously quantitative method for five anthocyanins using ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) was established here. Good linear relationships were obtained ranging from 1 to 100 ng/mL (R2 > 0.99). In addition, the specificity, recovery, stability, and matrix effect met requirements of analytical methodology. The method successfully monitored the concentrations of five anthocyanins in plasma and studied their pharmacokinetics after oral administration of 270 mg of anthocyanin extract in Sprague–Dawley rats. Pharmacokinetic parameters for delphinidin-3-O-glucoside (D3G), malvidin-3-O-glucoside (M3G), malvidin-3-O-arabinoside (M3A), delphinidin-3-O-arabinoside (D3A), and petunidin-3-O-arabinoside (P3A) showed the similar short Tmax 0.25–0.28 h and medium speed T1/2 3.24–3.52 h. It indicated anthocyanins were quickly absorbed and taken effectively, but eliminated in blood at an appropriate rate. Contents of D3G and M3G in anthocyanin extract are approximately equivalent, while the total amount and maximum concentration of M3G were twice those of D3G in plasma. This demonstrated that there were many differences between the substance contents of anthocyanin monomers in vitro and their absorption and distribution behaviors in vivo. Multiple peaks in both concentration–time profiles and bile excretions for five anthocyanins suggested the possibility of enterohepatic circulation in rats. The present study developed and validated a rapid and sensitive bioanalytical method based on UPLC–MS/MS for quantifying major anthocyanins from a novel blueberry extract in rat plasma to further understand their absorption, distribution, and metabolism. [ABSTRACT FROM AUTHOR]

Introduction: Our aim is to study the correlation between vitamin D metabolites and osteoporosis in rheumatoid arthritis (RA) by ultra-high-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS). At the same time, other influencing factors and serum biomarkers of osteoporosis in patients with RA were studied. Materials and methods: Patients with RA admitted from January 2020 to December 2020 were selected at our hospital. The subjects were divided into the normal bone mineral density (BMD), osteopenia, and osteoporosis groups. The differences of vitamin D (VD) metabolites among groups were compared. The Pearson correlation coefficient was used to analyze the relationship between BMD and various parameters. The relationship between BMD and influencing factors was studied by a multiple linear regression equation. Results: A total of 287 patients with RA were included. RA patients with 25-hydroxy vitamin D [25(OH)D] deficiency accounted for 43.63% and 25(OH)D insufficient levels accounted for 31.37%. There were 31 cases (10.80%) in the normal BMD group, 161 cases (56.10%) in the osteopenia group, and 95 cases (33.10%) in the osteoporosis group. The BMD of L1-4 (T- score) was negatively correlated with age (P < 0.05), course of disease (P < 0.05), and erythrocyte sedimentation rate (ESR) (P < 0.05), and positively correlated with 25(OH)D3 (P < 0.05). The multiple linear regression model results showed that age and 25(OH)D3 were independent predictors of BMD; this explained 22.11% of the total variation. Conclusions: VD deficiency and insufficient are common in RA patients. RA patients can be appropriately supplemented with VD. VD3 may be a better choice. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to develop and validate an ultraperformance liquid chromatography–tandem mass spectrometry to simultaneously determine diquat (DQ) and its two primary metabolites in rat plasma and its application to the toxicokinetic study. Method: The chromatographic separation of DQ and its two primary metabolites was performed with hydrophilic interaction chromatography column by adding formic acid and ammonium acetate in mobile phase in stepwise elution mode. DQ and its two primary metabolites were detected by liquid chromatography–tandem mass spectrometry in positive mode. Results: The lower limit of quantification ranging from 0.3 to 3.0 ng/mL for DQ and its two primary metabolites was achieved by using only 50 μL of rat plasma. The maximum concentration (Cmax) was 977 ng/mL, half-life (t1/2) was 13.1 h, and area under the plasma concentration–time curve (AUC0–t) was 2770 h*ng/mL for DQ, Cmax was 47.1 ng/mL, t1/2 was 25.1 h, and AUC0–t was 180 h·ng/mL for diquat monopyridone (DQ-M) and Cmax was 246 ng/mL, t1/2 was 8.2 h, and AUC0–t was 2430 h·ng/mL for diquat dipyridone (DQ-D), respectively. Conclusions: The validated method was shown to be suitable for simultaneous determination of diquat and its two primary metabolites in rat plasma. This study is the first to study the toxicokinetics of DQ and its two primary metabolites. [ABSTRACT FROM AUTHOR]

Seven parabens including methylparaben (MeP), ethylparaben (EtP), propylparaben (PrP), iso-propylparaben (iPrP), butylparaben (BuP), benzylparaben (BzP), and heptylparaben (HepP) were determined in bottled water, tap water, river water, lake water, and wastewater samples collected from Hanoi, Vietnam, using solid phase extraction (SPE) followed by ultrahigh performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The highest total concentration of parabens were measured in wastewater (range, 27.3–1050 ng/L; mean/median, 268/175 ng/L), followed by lake water (range, 18.0–254 ng/L; mean/median, 51.7/58.5 ng/L), river water (range, 16.5–52.1 ng/L; mean/median, 32.1/42.6 ng/L), tap water (range, 5.01–54.3 ng/L; mean/median, 28.6/41.1 ng/L), and bottled water (range, 1.56–39.9 ng/L; mean/median, 6.92/9.19 ng/L). Methylparaben and propylparaben were the predominant compounds found in all samples. The mean estimated human exposure dose of parabens through drinking bottled water was 0.27 ng/kg-bw/day, which is 6 orders of magnitude below the safety threshold recommended by the Joint FAO/WHO Expert Committee on Food Additive in 1974 (10 mg/kg-bw/day). Concentrations of parabens measured in river water, lake water, and wastewater samples were assessed to pose low to moderate ecological risks to aquatic organisms (0.1 < RQ < 1). Methyl, ethyl, and propyl parabens exhibited significant correlations in water samples. [ABSTRACT FROM AUTHOR]

A reliable and affordable QuEChERS (quick, easy, cheap, effective, rugged, and safe) methodology in combination with ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC–MS/MS) was successfully developed and validated for the determination of eight bisphenols (BPs) residues containing in meats (chicken, duck, beef, pork, fish, shrimp, and mutton). A novel QuEChERS method optimization was carried out in terms of process efficiency (PE), matrix effect (ME), and extraction recovery (RE). After a simple vortex extraction of the samples with acetonitrile, 1 g sodium acetate was used for salting out (NaAC), and 100 mg primary secondary amine (PSA) purifying reagents were used for purification. The properties of the sorbents were assessed by the obtained parameters, such as matrix effect (ME), linearity, sensitivity, accuracy, and precision. Under the optimal conditions, BPs were well separated on an ACQUITY UPLC BEH ® C18 column in 8 min by gradient elution, and exhibited a good linear relationship (R2 > 0.9988) in the linear range. Moreover, the limits of detection (LODs) and the limits of quantification (LOQs) were located in the range of 0.01– 0.11 μg/kg and 0.03 – 0.37 μg/kg, respectively. The developed method was satisfactory in terms of accuracy (relative recoveries: 76.1% – 113.7%) and precision (relative standard deviations below 10.3%). Finally, the developed method was successfully employed to identify and quantify BPs residues in 28 real meat samples. The proposed QuEChERS-UPLC–MS/MS method is simple, high efficiency, cost-effective, practical, and susceptible to being implemented in routine laboratories to quickly detect the BPs in meats (chicken, duck, beef, pork, fish, shrimp, and mutton). In this sense, the method is useful for obtaining BPs residue data to evaluate the contamination status of BPs in meat food and provide scientific support for scientific supervision. [ABSTRACT FROM AUTHOR]

Resveratrol with a high content in grapes has beneficial effects on inflammation, endothelial function, oxidative stress and cardiovascular and cerebrovascular diseases. Here, we propose a sensitive analytical method basing on the ultrasonic-assisted extraction followed by ultra-high performance liquid mass spectrometry to simultaneously determine trans-resveratrol (RES), trans-resveratrol 3-O-β-D-glucuronide, trans-resveratrol 4ʹ-O-β-D-glucuronide (R4G) in grapes. Single factor experiment and response surface methodology were used to optimize the pretreatment process of grape samples. The optimal conditions were as follows: extraction solvent-ethyl acetate, ultrasonic temperature 62 °C, ultrasonic time 20 min, ultrasonic power 90% and the volume of the extracted solvent 3500 μL. The method showed the good linearity (r ≥ 0.9917), the satisfactory intra-day (%RSD ≤ 11.3%) and inter-day precision (%RSD ≤ 14.5%) and low limit of quantification (0.1 μg/mL). This proposed method was successfully applied to determine RES, R3G, R4G in different grapes, achieving satisfactory recoveries (88.8–116.9%). Thus, this method established in this study is simple and time-saving, which will be helpful to the development and utilization of RES, R3G, R4G in grapes in food and pharmaceutical industries. [ABSTRACT FROM AUTHOR]

An analytical method of simultaneous detection of ten insecticide residues in honey and pollen was established. The samples were purified with QuEChERS approach using new adsorbents and analyzed with UPLC-MS/MS. The results showed that both of graphene and carbon nanotubes were highly efficient adsorbents for the dSPE clean up to eliminate coextractives in the samples, and graphene was superior to carbon nanotubes for the detection of pesticide residues in honey and pollen samples. The proposed method was used to detect pesticide residues in 25 honey samples and 30 pollen samples which were randomly collected from more than ten provinces in China. All honey samples contain 1–27 μg/kg of chlorpyrifos residues. Only 4% of the honey samples were detected containing acetamiprid and imidacloprid, while the other seven pesticides were not detected. Chlorpyrifos residues were found in all pollen samples (5–66 μg/kg), among which twenty percent exceeded the maximum residue limits (MRLs, 50 μg/kg, European Commission Regulation). Most of the pollen samples containing pesticide concentrations higher than MRLs were collected from rape, followed by lotus, camellia, and rose. Besides, 36.7% and 33.3% of the pollen samples had imidacloprid and flupyradifurone higher than 5 μg/kg. A total of 26.7% pollen samples were detected containing bifenthrin, while none of the other six pesticides were detected in pollen samples. [ABSTRACT FROM AUTHOR]

Pentachlorophenol (PCP) and sodium pentachlorophenate (PCP-Na) are both organochlorine pesticides. Excessive use of PCP-Na can cause water and soil pollution. In this study, a new method was established to verify the residual amount of PCP-Na in samples through the combination of PAX solid-phase extraction and ultra-high performance liquid chromatography-tandem mass spectrometry. The sample containing PCP-Na was extracted with acetonitrile solution and subjected to PAX anion solid-phase extraction. After eluting with acid methanol solution, the content of PCP was separated and detected on the ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The method has good detection performance in the PCP-Na at the concentration range of 1–20 ug/L, and the experimental method is simple to operate and accurate. The result shows that different types of solid extraction impact the detection ability of PCP-Na. Using a suitable extraction column can effectively reduce the impact of impurities on the detection of PCP-Na. The ceramic homogenizer addition can make the recovery rate of PCP-Na in the test sample higher. The recovery rate of PCP-NA of frozen-extracted samples is higher than that of samples that have not been frozen-extracted. It is recommended that samples processed under frozen-extracted and ceramic homogenizer addition can obtain better separation results. [ABSTRACT FROM AUTHOR]

Background: 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and 1,2-dipalmitoyl-sn-glycerol-3-phosphorylcholine (DPPC) are two common phosphatidylcholines that are the critical components of bilayer membrane structure. Methods: To detect DMPC and DPPC, an ultra-high-performance liquid chromatography–mass spectrometry (UPLC-MS/MS) method was established. DMPC and DPPC were separated on an amide column with gradient elution and determined by multiple reaction monitoring at m/z 678.6 → 184.3 (DMPC) and 734.5 → 184.03 (DPPC). Results: The method was validated and applied to determine the concentration of DMPC and DPPC in paraquat (PQ)-poisoned cells and serum. DMPC and DPPC showed a good linear relationship in both extracellular media. The precision and accuracy of DMPC and DPPC were within 15%. The extracellular concentrations of DMPC and DPPC increased gradually from 12 to 72 h. Spearman analysis of DMPC and DPPC showed that the correlation coefficient was 0.774 in the control group and 0.621 in the PQ group. In conclusion, a rapid and specific UPLC-MS/MS method for detecting DPPC and DMPC was developed and validated. There was a significant correlation between DMPC and DPPC. PQ poisoning decreased the correlation between DPPC and DMPC. [ABSTRACT FROM AUTHOR]

Purpose: Paraquat and diquat are well-known toxic herbicides, at least responsible for hundreds of fatal poisoning events worldwide. However, the determination of diquat and paraquat in plasma and urine is very challenging because of their high polarity and double charge characteristics. In this study, we aim to develop a rapid and reliable method for the determination of paraquat and diquat in human plasma and urine by ultraperformance liquid chromatography–tandem mass spectrometry. Method: The chromatographic separation of paraquat and diquat was tested with different chromatographic columns and different mobile phase conditions. The mass parameters were optimized by product ions, source gas flow, cone flow, desolvation temperature, and capillary voltage. The isocratic elution mode gave rapid appearance of peak of paraquat and diquat. Results: The sharp peak shapes for paraquat and diquat were achieved with CORTECS® UPLC® HILIC (100 × 2.1 mm, 1.6 μm) column by adding formic acid and ammonium acetate in mobile phase in isocratic elution mode. The lower limit of quantification of 1.0 ng/mL for paraquat and diquat were achieved using only 50 μL of human plasma or urine. The running time for analysis of both paraquat and diquat was as short as 3.5 min per sample. Conclusions: A rapid and reliable method for the determination of paraquat and diquat was developed and applied to 387 clinical poisoning cases and 22 poisoning cases were found to be paraquat or diquat poisoning. [ABSTRACT FROM AUTHOR]

A method based on QuEChERS (quick, easy, cheap, effective, rugged, and safe) sample preparation coupled with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed for determining 43 pesticide residues in strawberries. The clean-up sorbents were optimized, with 50 mg PSA + 50 mg C18 + 150 mg MgSO4 showing the best performance in d-SPE. The effect of injection volume on matrix effect (ME) was investigated. The proposed method had a linear range of 0.001–0.1 mg kg−1, and determination coefficients (R2) were greater than 0.995. Recoveries of the selected pesticides were 70.1–119.6% with relative standard deviations (RSD) at three concentrations (0.01, 0.05, and 0.1 mg kg−1) lower than 20%. The limit of quantification (LOQ) of the 43 pesticides was ≤ 0.005 mg kg−1. This method was applied to 80 strawberry samples collected from 8 villages in Beijing suburbs, and 12 pesticide residues were quantitatively detected with the concentrations ranging from 0.02 to 2.5 mg kg−1. [ABSTRACT FROM AUTHOR]

Isothiazolinones, a family of biocides, are used as preservatives for their fungicidal, bactericidal, and algacidal properties. These compounds can be found in a wide range of consumer and building products, such as paints, varnishes, shampoos, and liquid detergents. A robust analytical UPLC-MS/MS method to identify and quantify seven isothiazolinones (MIT, CMI, BIT, MBIT, BBIT, OIT, and DCOIT) in consumer products and their emissions was developed and validated according to ISO/IEC 17025. The limits of detection (LODs) ranged from 0.14 μg L−1 (BIT) to 0.54 μg L−1 (CMI). The method was applied for the quantification of the seven isothiazolinones in four types of consumer products (i.e., cosmetics, air fresheners, cleaning products, and building products) and the indoor emissions from a paint. Matrix effects were observed for the shampoo (63–74%), the shower gel (67–84%), and the ceramic glass cleaner (53–57%). All isothiazolinones indicated by the manufacturer (i.e., MIT, CMI, BIT, OIT, and DCOIT) were detected in the products and successfully quantified by the UPLC-MS/MS method. [ABSTRACT FROM AUTHOR]

High-dose methotrexate (HDMTX) combined with leucovorin (LV) is the first-line drug therapy for many kinds of malignant tumors. However, the specific treatment plans, such as dosage and duration of administration, are usually formulated according to the clinician's experience and therapeutic drug monitoring (TDM) of methotrexate in patients' plasma, which are responsible for strong individual differences of drug usage. A large number of studies have shown that methotrexate targets the inside of the cell. The key cytotoxic component is the methotrexate polyglutamates (MTXPGs) in the cell. The concentration of methotrexate in plasma does not reflect the efficacy and side effects well. Based on mass spectrometry technology, we developed and validated an accurate, sensitive, and stable method to quantify the intracellular MTX (MTXPG1) and its metabolites MTXPG2–7 simultaneously. The lower limit of quantification was 0.100 ng/ml, and the run time was only 3 min. Moreover, our team has already developed two LC-MS/MS-based methods to respectively quantify methotrexate in plasma samples and two key proteins (γ-glutamyl hydrolase [GGH] and folylpolyglutamate synthetase [FPGS]) in peripheral blood mononuclear cells (PBMC). Through these highly sensitive and accurate approaches, we have gained a deep understanding of the whole pharmacokinetic process of MTX and explored the key factors affecting the accumulation process of intracellular active components (MTXPGs). Based on this research, it is possible to find a more effective way to provide an accurate reference for clinical drug use than traditional therapeutic drug monitoring (TDM). [ABSTRACT FROM AUTHOR]

A rapid and sensitive UPLC-MS/MS method was developed and fully validated for the quantification of hyperoside in rat plasma after intragastric, intraperitoneal and intravenous administration. Geniposide was used as an internal standard, and simple liquid–liquid extraction by ethyl acetate was utilized for to extracting the analytes from the rat plasma samples. Chromatographic separation was carried out on an InfinityLab Poroshell 120EC-C18column (2.1 mm × 50 mm, 1.9-Micro, Agilent technologies, USA). The mobile phase consisted of methanol (A) and water (B) (containing 0.1% acetic acid) at a flow rate of 0.4 mL/min. A run time of 3 min for each sample made it possible to analyze more than 300 plasma samples per day. The validated linear ranges of hyperoside were 2–1000 ng/mL in rat plasma. The intra-day and inter-day precision were within 2.6–9.3%, and accuracy were ± 8.6%. And the results of recovery and matrix interference studies were well within the accepted variability limits. Finally, this method was fully validated and successfully applied to the pharmacokinetic studies of hyperoside via different administration routes in rats. [ABSTRACT FROM AUTHOR]

GreenTD (Dichlorobenzyl derivative, MW 362.17) is a new dichlorobenzyl derivative algaecide. It is effective and selective against harmful algal blooms (HABs). HABs cause serious problems for public health and fishery industries. Algae that cause HABs include Microcystis spp., Anabaena spp., and Aphanizomenon spp. Blooms of toxin-producing Microcystis aeruginosa occur regularly in fresh water where is rich in nitrogen and phosphorus nutrients. Environmental fate studies are needed to investigate the degradation of GreenTD. In the present study, we studied the persistence of GreenTD (90% aqueous solution) in water and toxic effects GreenTD on M. aeruginosa and reduction of microcystin production in the culture media. GreenTD was added in the water pots and microcystis media tubes at levels of 25 g/0.1 ha (0.5 mg/kg) and 50 g/0.1 ha (1.0 mg/kg). Samples were collected after 1, 3, 5, 7 and 14 days. The residues of GreenTD and microcystins in water and the media were determined using high performance liquid chromatography-diode array detection and ultra-performance liquid chromatography-tandem mass spectrometry, respectively. The half-life of GreenTD at concentrations of 0.5 and 1.0 mg/kg was 4.5 and 3.6 days, respectively. This result presents a safety level suitable for the acceptable guideline of water residue. The average recoveries of microcystins RR, YR, LR, and LA were 106–115%, 103–110%, 96–105% and 89–113% in the microcystis media, respectively. The limit of detection of (LOD) the microcystins was 0.1 µg/kg. No microcystins in the media were detected at the LOD (0.1 µg/kg). GreenTD at concentrations of 0.2 and 0.5 µg/kg had a 100% of control efficacy of M. aeruginosa. No growth of the blue-green algae was observed after 14 days of GreenTD application. [ABSTRACT FROM AUTHOR]

A sensitive and selective assay based on liquid chromatography–tandem mass spectrometric method was developed for quantification of phorate in river water. The chromatographic separation of phorate was achieved on Zorbax C18 column using two mobile phase consisting 0.1% formic acid in methanol, and 0.1% formic acid in MilliQ water (v/v ratio of 96:04) by isocratic elution method at a flow rate of 300 µL/min. The quantification was carried out using multiple reaction monitoring transitions of m/z 261/75 for phorate. The lower limit of detection and limit of quantification for the developed UPLC-MS/MS was 0.08 ng/mL and of 0.19 ng/mL respectively. The assay was validated for selectivity, linearity, accuracy and precision. The developed assay was then employed for quantification of phorate in river water and wetland treated water. The role of constructed wetlands (CW) in phorate removal was established in this study. The removal efficiency of phorate by Constructed Wetland was found to be 60–90% along with an overall 70–90% reduction in chemical oxygen demand (COD), biological oxygen demand (BOD) and phosphorus (P). [ABSTRACT FROM AUTHOR]

Securidaca inappendiculata Hassk. is a traditional Chinese anti-rheumatic herbal medicine native to southern China. In this study, we identified a possible TLR4 inhibitor from this plant. General effects of its xanthone-rich fraction (XRF) on inflammation in vitro were investigated by immunoblotting experiments performed on lipopolysaccharides (LPS)-treated RAW264.7 cells, and the possible ligand of TLR4 within was screened out by analyzing chemical composition differences of the XRF containing cell culture medium under different inflammatory circumstances. The interaction between ligand and TLR4 was validated by cellular thermal shift assay (CETSA) and molecular docking simulation, and TLR4/NF-κB pathway status was investigated by immunoprecipitation, ELISA, immunofluorescence, dual-luciferase reporter, and immunoblotting experiments. Treatment with XRF resulted in significant decrease in p-p65 and p-JNK, and the signal accounting for 1,7-dihydroxy-3,4-dimethoxyxanthone (XAN) at 12.5 min with mass of 289.29 was greatly decreased in XRF containing medium after LPS stimulus because of enhanced interaction with increased TLR4. CETSA and molecular docking simulation demonstrated that XAN could bind to TLR4 directly on a smooth region adjacent to its contact interface with MD-2. XAN treatment inhibited the dimerization of TLR4 and transcriptional activity of NF-κB in HEK293T cells and decreased p65 accumulation in nucleus and pro-inflammatory cytokines production in RAW264.7 cells receiving LPS treatment. Overall evidences suggest that XAN could be a selective TLR4 inhibitor with potent anti-inflammatory effects. Also, it indicated that xanthone derivatives could have promising clinical application in many immune-mediated inflammations by acting as TLR4 inhibitors. [ABSTRACT FROM AUTHOR]

CYP2E1 is one of the most crucial isozymes of CYP450. It is responsible for metabolizing and activating a large number of toxicants and carcinogens, but the correlation between its abundance and activity has not been widely studied. With the flourishing of modern mass spectrometry technology, quantifying complex biological proteins and studying the relationship between their abundance and activity have become practicable. In our study, an accurate, sensitive, and stable LC-MS/MS-based method was developed and validated. The method can accurately quantify the abundance of CYP2E1 in the rat liver microsome and S9 fraction. The quantitative linearity of the method is between 2 and 320 ng/mL, and the run time is 16.5 minutes. Meanwhile, we used the probe substrate method (with chlorzoxazone as the substrate) as a reference to analyze the correlation between its activity and abundance. The result illustrated that the abundance of CYP2E1 by LC-MS/MS has a strong positive correlation with its activity. This is a relationship worth studying, which has not been reported before. We also explored the correlation between quantitative results by traditional methods (western blot and RT-PCR) and activity, and the positive correlation was not obvious. Therefore, when testing the correlation between metabolic enzyme abundance and activity, the LC-MS/MS-based method is confirmed to be more accurate than conventional methods. It will provide a meaningful way of researching the metabolic enzymes in drug interactions. Furthermore, we found that the S9 fraction can also be used for mass spectrometry quantitative analysis, which is helpful for promoting the practical application of targeted protein technology. [ABSTRACT FROM AUTHOR]

Bitter melon is a source of bioactive compounds, such as phenolic compounds and is widely used as medicinal and food plant. This study aimed at evaluating the distribution of phenolic compounds in the different parts (pulp, peel and seeds) of ripe bitter melon fruit (Momordica charantia) and in the whole unripe fruit through its quantification by UPLC–MS/MS using a proposed ultrasonic-assisted extraction method. Altogether, 18 phenolic compounds were determined in samples from bitter melon. The pulp of the ripe fruit and the whole unripe fruit showed the highest amounts of total phenolic compounds, 964.00 ± 15.64 and 918.63 ± 18.22 mg g−1, respectively. It was possible to identify naringenin, chrysin, luteolin and apigenin in unripe fruit, and chrysin and apigenin in all parts of the ripe fruit. These phenolic compounds had not been previously reported in other studies for bitter melon. Thus, the pulp can be considered as a promising source of phenolic compounds, deserving attention in future studies. [ABSTRACT FROM AUTHOR]

Cefotaxime is a third-generation broad-spectrum cephalosporin acting on a wide range of Gram-positive and Gram-negative bacteria. In this work, the pharmacokinetics of cefotaxime were determined in dromedary camel calves by single intravenous injection of 10 mg/kg b.w. Cefotaxime levels were estimated by ultra-high performance liquid chromatography-mass spectrometry (UPLC-MS/MS). Cefotaxime pharmacokinetics in camel calves obeyed three-compartment kinetics model. There was a central compartment and two peripheral, one shallow and one deep compartment. The shallow compartment equilibrates very rapidly with distribution half-life (t1/2α) of 0.6 min, while the deep compartment has large distribution half-life (t1/2β) of 42 min indicating slower uptake of cefotaxime. The elimination rate constant (γ = 0.04 h−1) and elimination half-life (t1/2 γ) = 15.46 h indicating slow elimination. In comparison with other animals, cefotaxime pharmacokinetics in camel calves showed potential wide distribution in multi-compartment, lower elimination constant, lower clearance and higher volume of distribution at steady state. This indicates substantial differences in cefotaxime pharmacokinetics in camel calves with a very characteristic ultra-rapid distribution into three-compartment and slow elimination. [ABSTRACT FROM AUTHOR]

Introduction: Ocular inflammation is a key pathogenic factor in most blindness-causing visual disorders. It can manifest in the aqueous humor (AH) and tear fluid (TF) as alterations in polyunsaturated fatty acids (PUFAs) and their metabolites, oxylipins, lipid mediators, which are biosynthesized via enzymatic pathways involving lipoxygenase, cyclooxygenase or cytochrome P450 monooxygenase and specifically regulate inflammation and resolution pathways. Objectives: This study aimed to establish the baseline patterns of PUFAs and oxylipins in AH and TF by their comprehensive lipidomic identification and profiling in humans in the absence of ocular inflammation and comparatively analyze these compounds in the eye liquids of rabbits, the species often employed in investigative ophthalmology. Methods: Ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was used for qualitative and quantitative characterization of lipid compounds in the analyzed samples. Results: A total of 28 lipid compounds were identified, including phospholipid derivatives and PUFAs, as well as 22 oxylipins. Whereas the PUFAs included arachidonic, docosahexaenoic and eicosapentaenoic acids, the oxylipins were derived mainly from arachidonic, linoleic and α-linolenic acids. Remarkably, although the concentration of oxylipins in AH was lower compared to TF, these liquids showed pronounced similarity in their lipid profiles, which additionally exhibited noticeable interspecies concordance. Conclusion: The revealed correlations confirm the feasibility of rabbit models for investigating pathogenesis and trialing therapies of human eye disorders. The identified metabolite patterns suggest enzymatic mechanisms of oxylipin generation in AH and TF and might be used as a reference in ocular inflammation studies. [ABSTRACT FROM AUTHOR]