Quadrupole Tandem Mass Spectrometry Research Articles

Trace Elements and Persistent Organic Pollutants in Unhatched Loggerhead Turtle Eggs from an Emerging Nesting Site along the Southwestern Coasts of Italy, Western Mediterranean Sea

Marine pollution is one of the major threats affecting loggerhead turtles, which due to their long life span, highly migratory behavior, and carnivorous diet, may be exposed to elevated levels of toxic elements throughout their life. The transfer of chemicals from mothers to their offspring is of particular conservation concern because it may affect embryonic development and hatching success. In this study, the concentrations of 16 toxic and potentially toxic trace elements, 6 indicator polychlorinated biphenyls (PCBs), and organochlorine pesticide residues (OCPs) were determined in 138 eggs from 46 loggerhead turtle nests laid during the 2021 nesting season in Campania, Italy, western Mediterranean Sea. The possible impact of pollutant levels on hatching success and early embryonic death was also investigated. Trace element analysis was performed using an ICP-MS, except for mercury, which was determined using a Direct Mercury Analyzer® (DMA). PCBs and OCPs were analyzed with high-resolution gas chromatography coupled with high-resolution mass spectrometry (HRGC-HRMS) and gas chromatography tandem quadrupole mass spectrometry GC-MS /MS, respectively. The concentrations of essential elements in the eggs were higher than those of non-essential elements. In addition, the highly chlorinated PCBs (153, 138, and 180) contributed the most to the total PCBs, while OCPs were not detected. No correlations were found between contaminant concentrations and reproductive parameters (hatching success and no obvious embryos). The results obtained suggest that the levels of contaminants found in the eggs do not affect the reproductive success of the species in the study area.

Ability of a Polyphenol-Rich Nutraceutical to Reduce Central Nervous System Lipid Peroxidation by Analysis of Oxylipins in Urine: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial.

Isoprostanes (IsoPs) are lipid peroxidation biomarkers that reveal the oxidative status of the organism without specifying which organs or tissues it occurs in. Similar compounds have recently been identified that can assess central nervous system (CNS) lipid peroxidation status, usually oxidated by reactive oxygen species. These compounds are the neuroprostanes (NeuroPs) derived from eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and the F2t-dihomo-isoprotanes derived from adrenic acid (AdA). The aim of the present investigation was to evaluate whether the long-term nutraceutical consumption of high polyphenolic contents (600 mg) from fruits (such as berries) and vegetables shows efficacy against CNS lipid peroxidation in urine biomarkers. A total of 92 subjects (47 females, 45 males, age 34 ± 11 years old, weight 73.10 ± 14.29 kg, height 1.72 ± 9 cm, body mass index (BMI) 24.40 ± 3.43 kg/m2) completed a randomized, cross-over, double-blind study after an intervention of two periods of 16 weeks consuming either extract (EXT) or placebo (PLA) separated by a 4-week washout period. The results showed significant reductions in three AdA-derived metabolites, namely, 17-epi-17-F2t-dihomo-IsoPs (Δ -1.65 ng/mL; p < 0.001), 17-F2t-dihomo-IsoPs (Δ -0.17 ng/mL; p < 0.015), and ent-7(RS)-7-F2t-dihomo-IsoPs (Δ -1.97 ng/mL; p < 0.001), and one DHA-derived metabolite, namely, 4-F4t-NeuroP (Δ -7.94 ng/mL; p < 0.001), after EXT consumption, which was not observed after PLA consumption. These data seem to show the effectiveness of the extract for preventing CNS lipid peroxidation, as determined by measurements of oxylipins in urine through Ultra-High-Performance Liquid Chromatography triple quadrupole tandem mass spectrometry (UHPLC-QqQ-ESI-MS/MS).

Polygoni Multiflori Radix interferes with bile acid metabolism homeostasis by inhibiting Fxr transcription, leading to cholestasis.

Objective: To explore the possible mechanisms of cholestasis induced by Polygoni Multiflori Radix (PM). Methods: Low and high doses of water extract of PM were given to mice by gavage for 8weeks. The serum biochemical indexes of aspartate aminotransferase (AST), alanine aminotransferase (ALT), glutamyltransferase (GGT) alkaline phosphatase (ALP) and so on were detected in the second, fourth, sixth, and eighth weeks after administration. At the end of the eighth week of administration, the bile acid metabolic profiles of liver and bile were screened by high-performance liquid chromatography tandem triple quadrupole mass spectrometry (HPLC-QQQ-MS/MS). Liver pathological changes were observed by hematoxylin and eosin staining. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect the mRNA transcription of the target genes and Western blotting (WB) was used to the detect target protein expression. Results: Biochemical tests results showed the values of ALP and GGT were two and three times greater than the normal values respectively, and the value of R was less than 2. Histopathology also showed that PM caused lymphocyte infiltration, a small amount of hepatocyte necrosis and nuclear fragmentation in mouse liver. The proliferation of bile duct epithelial cells was observed in the high group. These results indicated that PM may lead to cholestatic liver injury. HPLC-QQQ-MS/MS analysis with the multivariate statistical analysis revealed significant alterations of individual bile acids in liver and gallbladder as compared to those of the control group. RT-qPCR showed that the transcription of Fxr, Shp, Bsep, Bacs, Mdr2, and Ugt1a1 were downregulated and that of Cyp7a1, Mrp3, and Cyp3a11 was significantly upregulated in the treatment group. WB demonstrated that PM also markedly downregulated the protein expression of FXR, BSEP, and MDR2, and upregulated CYP7A1. Conclusion: PM inhibited the expression of FXR, which reduced the expression of MDR2 and BSEP, leading to the obstruction of bile acids outflow, and increased the expression of CYP7A1, resulting in an increase of intrahepatic bile acid synthesis, which can lead to cholestasis.

A sensitive LC-MS/MS method-based pharmacokinetic study of fifteen active ingredients of Yindan Xinnaotong soft capsule in rats and its potential mechanism in the treatment of cardiovascular diseases

Yindan Xinnaotong soft capsule (YDXNT) is a commonly used Chinese herbal preparation for the clinical treatment of coronary disease. However, there is a lack of pharmacokinetic studies on YDXNT, and its active ingredients and their mechanism in the treatment of cardiovascular diseases (CVD) are still unclear. In this study, 15 absorbed ingredients in rat plasma after oral administration of YDXNT were quickly identified based on liquid chromatography tandem quadrupole time-of-flight mass spectrometry (LC-QTOF MS), and then a sensitive and accurate quantitative method based on ultra-high performance liquid chromatography tandem triple quadrupole mass spectrometry (UHPLC-QQQ MS) was established and validated for simultaneous determination of the 15 ingredients of YDXNT in rat plasma, which was then applied to the pharmacokinetic study. Different types of compounds showed various pharmacokinetic characteristics, for instance, ginkgolides with higher maximum plasma concentration (Cmax), flavonoids presenting concentration–time curve with double peaks, phenolic acids with shorter time to reach maximum plasma concentration (Tmax), saponins with long elimination half-life (t1/2) and tanshinones showing fluctuant plasma concentration. Then the measured analytes were regarded as effective compounds and their potential targets and mechanism of action were predicted by constructing and analyzing the compound-target network of YDXNT and CVD. Those potential active compounds of YDXNT interacted with targets such as MAPK1 and MAPK8, and molecular docking showed that the binding free energies of 12 ingredients with MAPK1 were less than −5.0 kcal/mol, indicating that YDXNT intervened in the MAPK signaling pathway to display its therapeutic effect on CVD.

Characterization and quantification of chemical constituents in Angong Niuhuang Pill using ultra-high performance liquid chromatography tandem mass spectrometry

Material basis researches and quality evaluation of traditional Chinese medicine preparations (TCMPs) face great challenges due to the complex composition and abundant unexpected interference. Angong Niuhuang Pill (ANP), one of the most famous TCMPs in China, containing 11 crude drugs has been commonly used for the treatment of febrile diseases. However, previous literatures of comprehensive chemical constituents in ANP were still limited. Herein, Ultra-high performance liquid chromatography-ion mobility-quadrupole time-of-flight mass spectrometry (UHPLC-IM-QTOF MS) method was established to effectively recognize the chemicals in Angong Niuhuang Pill (ANP). A total of 205 compounds, containing 72 confirmed with reference standards, were characterized from ANP with the application of a systematic strategy integrated polygonal mass defect filtering (MDF) and diagnostic fragment ion filtering (DFIF)/neutral loss filtering (NLF). Additionally, 68 major constituents in 8 batches of ANP samples were simultaneously determined by ultra-performance liquid chromatography-triple quadrupole tandem mass spectrometry (UPLC-QQQ MS/MS) within 40 min. The quantitative method was validated regarding linearity, precision, repeatability, stability, and accuracy. These findings proved the established liquid chromatography-mass spectrometry (LC-MS) method was efficient and dependable for qualitative and quantitative chemical profiling of ANP. Besides, this research could provide the material basis for further pharmacological researches and quality control of ANP.

Human exposure to polycyclic aromatic hydrocarbons in the atmosphere of an agricultural area of central Chile and inhalation cancer risk assessments

Polycyclic aromatic hydrocarbons (PAHs) are persistent toxic substances prone to long-range atmospheric transport. Even in low concentrations, environmental exposure to PAHs can impact human health. In this study we aimed to i) investigate the occurrence of 15 polycyclic aromatic hydrocarbons (∑15PAHs), from August 2016 to January 2018, in the atmosphere of Molina, using polyurethane foam disks (PAS-PUF) in central Chile; and ii) perform deterministic and probabilistic (using Monte Carlo simulations) inhalation cancer risk assessments.Gas chromatography and tandem quadrupole mass spectrometry (GC- MS/MS) measured target PAHs. Results showed ∑15PAHs ranging from 2 ng m-3 to 108 ng m-3, with four-ring PAHs as the prevalent compounds, including phenanthrene (44%) and fluoranthene (24%). Winter season showed the highest PAH levels (increasing factor up to ∼8 times). PAHs diagnostic ratios showed the prevalence of pyrogenic combustion (winter) and petrogenic combustion (summer). Lifetime cancer risk assessments, using BaP-eq values, indicated an increased cancer risk for the exposed population considering different risk assessment approaches. Younger individuals were the most affected by an increased cancer risk at all sampling sites. The Monte Carlo probabilistic assessment indicated that infants and toddlers could be exposed to PAH air concentrations exceeding the cancer risk threshold in over 94% of the simulations. The coldest months in the studied region are critical for human exposure and health risk due to intense wood combustion. Indoor air can be even more relevant due to the chronic inhalation of the smoke and associated chemicals.

Rapid profiling of DNA replication dynamics using mass spectrometry-based analysis of nascent DNA.

The primary method for probing DNA replication dynamics is DNA fiber analysis, which utilizes thymidine analog incorporation into nascent DNA, followed by immunofluorescent microscopy of DNA fibers. Besides being time-consuming and prone to experimenter bias, it is not suitable for studying DNA replication dynamics in mitochondria or bacteria, nor is it adaptable for higher-throughput analysis. Here, we present mass spectrometry-based analysis of nascent DNA (MS-BAND) as a rapid, unbiased, quantitative alternative to DNA fiber analysis. In this method, incorporation of thymidine analogs is quantified from DNA using triple quadrupole tandem mass spectrometry. MS-BAND accurately detects DNA replication alterations in both the nucleus and mitochondria of human cells, as well as bacteria. The high-throughput capability of MS-BAND captured replication alterations in an E. coli DNA damage-inducing gene library. Therefore, MS-BAND may serve as an alternative to the DNA fiber technique, with potential for high-throughput analysis of replication dynamics in diverse model systems.

A validated LC–MS/MS method for clinical pharmacokinetics and presumptive phase II metabolic pathways following oral administration of Andrographis paniculata extract

Andrographis paniculata, a medicinal plant in Thailand national list of essential medicines, has been proposed for treatment of patients with mild to moderate coronavirus disease 2019. This study aims to develop a highly selective and sensitive liquid chromatography triple quadrupole tandem mass spectrometry method for quantitative determination of major diterpenoids in plasma and urine with application in pharmacokinetics. Chromatographic separation was performed on C18 column using a gradient mobile phase of water and acetonitrile. Mass spectrometry was analyzed using multiple reaction monitoring with negative ionization mode. This validated analytical method was very sensitive, less time consuming in analysis, and allowed the reliability and reproducibility on its application. The clinical pharmacokinetics was evaluated after single oral administration of A. paniculata extract (calculated as 60 mg of andrographolide). The disposition kinetics demonstrated that major diterpenoids could enter into systemic circulation, but they are mostly biotransformed (phase II) into conjugated glucuronide and sulfate metabolites. These metabolites are predominantly found in plasma and then extremely eliminated, in part through urinary excretion. The successful application of this analytical method supports its suitable uses in further clinical benefits after oral administration of A. paniculata.

Prenatal exposure to pesticides and domain-specific neurodevelopment at age 12 and 18 months in Nanjing, China

BackgroundThe extensive usage of pesticides has led to a ubiquitous exposure in the Chinese general population. Previous studies have demonstrated developmental neurotoxicity associated with prenatal exposure to pesticides. ObjectivesWe aimed to delineate the landscape of internal pesticides exposure levels from pregnant women’s blood serum samples, and to identify the specific pesticides associated with the domain-specific neuropsychological development. MethodsParticipants included 710 mother-child pairs in a prospective cohort study initiated and maintained in Nanjing Maternity and Child Health Care Hospital. Maternal spot blood samples were collected at enrollment. Leveraging on an accurate, sensitive and reproducible analysis method for 88 pesticides, a total of 49 pesticides were measured simultaneously using gas chromatography-triple quadrupole tandem mass spectrometry (GC–MS/MS). After implementing a strict quality control (QC) management, 29 pesticides were reported. We assessed neuropsychological development in 12-month-old (n = 172) and 18-month-old (n = 138) children using the Ages and Stages Questionnaire (ASQ), Third Edition. Negative binomial regression models were used to investigate the associations between prenatal exposure to pesticides and ASQ domain-specific scores at age 12 and 18 months. Restricted cubic spline (RCS) analysis and generalized additive models (GAMs) were fitted to evaluate non-linear patterns. Longitudinal models with generalized estimating equations (GEE) were conducted to account for correlations among repeated observations. Weighted quantile sum (WQS) regression and Bayesian kernel machine regression (BKMR) were applied to examining the joint effect of the mixture of pesticides. Several sensitivity analyses were performed to assess the robustness of the results. ResultsWe observed that prenatal exposure to chlorpyrifos was significantly associated with a 4 % decrease in the ASQ communication scores both at age 12 months (RR, 0.96; 95 % CI, 0.94–0.98; P < 0.001) and 18 months (RR, 0.96; 95 % CI, 0.93–0.99; P < 0.01). In the ASQ gross motor domain, higher concentrations of mirex (RR, 0.96; 95 % CI, 0.94–0.99, P < 0.01 for 12-month-old children; RR, 0.98; 95 % CI, 0.97–1.00, P = 0.01 for 18-month-old children), and atrazine (RR, 0.97; 95 % CI, 0.95–0.99, P < 0.01 for 12-month-old children; RR, 0.99; 95 % CI, 0.97–1.00, P = 0.03 for 18-month-old children) were associated with decreased scores. In the ASQ fine motor domain, higher concentrations of mirex (RR, 0.98; 95 % CI, 0.96–1.00, P = 0.04 for 12-month-old children; RR, 0.98; 95 % CI, 0.96–0.99, P < 0.01 for 18-month-old children), atrazine (RR, 0.97; 95 % CI, 0.95–0.99, P < 0.001 for 12-month-old children; RR, 0.98; 95 % CI, 0.97–1.00, P = 0.01 for 18-month-old children), and dimethipin (RR, 0.94; 95 % CI, 0.89–1.00, P = 0.04 for 12-month-old children; RR, 0.93; 95 % CI, 0.88–0.98, P < 0.01 for 18-month-old children) were associated with decreased scores. The associations were not modified by child sex. There was no evidence of statistically significant nonlinear relationships between pesticides exposure and RRs of delayed neurodevelopment (Pnonlinearity > 0.05). Longitudinal analyses implicated the consistent findings. ConclusionThis study gave an integrated picture of pesticides exposure in Chinese pregnant women. We found significant inverse associations between prenatal exposure to chlorpyrifos, mirex, atrazine, dimethipin and the domain-specific neuropsychological development (i.e., communication, gross motor and fine motor) of children at 12 and 18 months of age. These findings identified specific pesticides with high risk of neurotoxicity, and highlighted the need for priority regulation of them.

Butylene Glycol Used as a Sustainable Solvent for Extracting Bioactive Compounds from Camellia sinensis Flowers with Ultrasound-Assisted Extraction.

The research aims to assess the yield of bioactive compounds and their antioxidant activities obtained from tea flowers using an ultrasound-assisted extraction method with butylene glycol (BG-UAE) through Box-Behnken design. It investigates the bioactive compounds including the total phenolic content (TPC), total flavonoid content (TFC), and total tannin content (TTC) and analyzes their antioxidant activities, bioactive compound composition by liquid chromatography triple quadrupole tandem mass spectrometry, and their cellular activities via UAE and maceration using BG or ethanol as the solvent. Under optimal conditions, the values of the TPC, TFC, TTC, 1,1-diphenyl-2-picrylhydrazil radical scavenging assay, 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid radical scavenging assay, and ferric reducing antioxidant power assay (FRAP) of the BG-UAE extract were 54.00 ± 1.19 mg GAE/g sample, 291.47 ± 3.34 mg QE/g sample, 65.37 ± 1.78 mg TAE/g sample, 106.45 ± 1.21 mg TEAC/g sample, 163.58 ± 2.76 mg TEAC/g sample, and 121.31 ± 4.75 mg FeSO4/g sample, respectively. Except for FRAP, BG-UAE exhibited the highest values in all parameters compared to the other extraction methods. Catechins and caffeine were predominantly detected in tea flower extracts through UAE with BG and ethanol (EtOH-UAE). BG-UAE exhibited greater cell viability and cellular antioxidant activity than EtOH-UAE. The researcher expects that this research will contribute to the emergence of a green extraction technique that will offer larger functional components with economic and environmental benefits and minimal chemicals and energy use.

Detection of Leachable Components from Conventional and Dental Bulk-Fill Resin Composites (High and Low Viscosity) Using Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) Method.

The aim of this study was to investigate leachable components (monomers) in high and low viscosity dental bulk-fill resin composites and conventional resin composite materials after polymerization. Six bulk-fill and six conventional dental resin composite materials were used in this study. The samples of each material (three sets of triplicates) were cured for 20 s with irradiance of 1200 mW/cm2 with a LED curing unit and immersed in a 75% ethanol solution at 37 °C. The eluates from each triplicate set were analyzed after 24 h, 7 days or 28 days using liquid chromatography coupled with triple quadrupole tandem mass spectrometry (LC-MS/MS). Detectable amounts of 2-Hydroxyethyl methacrylate (HEMA) were found in both Gradia materials and the amount observed across different time points was statistically different (p ˂ 0.05), with the amount in solution increasing for Gradia and decreasing for Gradia Direct flo. Bisphenol A diglycidildimethacrylate (BIS GMA) was found in Filtek and Tetric materials. Triethylene glycol dimethacrylate (TEGDMA) was detected in all materials. On the other hand, there were no statistically significant differences in the amounts of TEGDMA detected across different time points in either of the tested materials. Monomers HEMA, TEGDMA, 4-dimethylaminobenzoic acid ethyl ester (DMA BEE) and BIS GMA in bulk-fill and conventional composites (high and low viscosity) can be eluted after polymerization. The good selection of composite material and proper handling, the following of the manufacturer's instructions for polymerization and the use of finishing and polishing procedures may reduce the elution of the unpolymerized monomers> responsible for the possible allergic and genotoxic potential of dental resin composites.

Simultaneous Determination of Fungicides in Wood and Bamboo Food-Contact Materials by High-Performance Liquid Chromatography–Tandem Mass Spectrometry (HPLC–MS/MS)

Bamboo and wood are widely used as food contact materials (FCMs). Fungicides are often applied during the manufacture of these products to prevent mildew; thus, monitoring for fungicide residues is essential because of the possible risks to food safety. However, it is not clear whether residual fungicides in treated bamboo and wood products migrate into food to cause harm to humans, and there is an absence of procedures for these analyses. In this study, the simultaneous determination of fungicides was validated in bamboo and wood FCMs by high-performance liquid chromatography–triple quadrupole tandem mass spectrometry (HPLC–MS/MS). The analytes were extracted with methanol or 1:1 methanol/acetonitrile and purified using 25 mg primary secondary amine adsorbent with 2.5 mg graphitized carbon black or 25 mg PSA with 25 mg octadecylsilane (C18). The recoveries for wood and bamboo FCMs were from 60.0% to 100.7% and 70.0% to 97.5%, respectively. The intra-day precision of wood and bamboo FCMs were from 0.1% to 5.3% and 0.1 to 3.0%, and the inter-day precision from 0.3% to 8.5% and 1.2% to 7.8%, respectively. The limits of detection ranged from 0.11 to 15.38 for wood and 0.25–6.19 μg kg−1 for bamboo. This method provides a reference for the determination of fungicides in bamboo and wood FCMs.

The association of serum serine levels with the risk of incident cancer: results from a nested case-control study.

Background: Cancer is associated with the dysregulation of serum serine levels, and tumor growth is supported by increased serine biosynthesis. This study aims to explore the association of serum serine levels with incident cancer risk in Chinese hypertensive adults. Materials and methods: 1391 patients with incident cancer and 1391 matched controls in terms of age, sex, and residence with cases in a 1 : 1 ratio were included in this nested case-control study. The serum serine concentrations were determined by liquid chromatography with tandem quadrupole mass spectrometry (LC-MS/MS) at the baseline. The associations of serum serine levels with the risk of overall, digestive system, non-digestive system, and lung cancers (the most common type) were assessed by conditional logistic regression. Results: When serum serine concentration was assessed as quartiles, a significantly higher risk of total cancer (OR = 1.32; 95% CI: 1.01-1.71; P = 0.038) was found in participants in the highest quartile (≥17.68 μg mL-1) compared with participants in the lowest quartile (<13.27 μg mL-1). Similar results were also observed for non-digestive system and lung cancers, but not for digestive system cancers. Significant associations of serum with overall cancer risk were found among all age subgroups, men, non-smokers, non-drinkers, and individuals with lower folic acid levels. Conclusion: High serum serine concentrations were associated with an increased risk of overall, non-digestive system, and lung cancers among Chinese hypertensive adult patients.

A Rapid Determination of 30 Prohibited Pesticide Residues in Lycii Fructus by UPLC-MS/MS

Prohibited pesticide residues have become one of the main factors affecting the quality and safety of Lycii Fructus, However, rarely studies focus on the rapid determination of these residues. Here, a total of 30 kinds of prohibited pesticide residues were determined by ultra-performance liquid chromatography tandem triple quadrupole mass spectrometry (UPLC-MS/MS) in five different process ways. Pretreatment methods, chromatographic separation and detection conditions in mass spectrometry were all optimized accordingly. Among the five different pretreatment methods, the first and third solid phase extraction failed to provide high recoveries of sulfosulfuron compounds (both lower than 60%). Recovery of chlorphenamidine by the Quick Easy Cheap Effective Rugged and Safe multiresidue method (QuEChERS) was lower than 60%, which did not meet the requirements of trace determination. The concentrations of 30 prohibited pesticides residues treated by straightforward and solid phase extraction showed good linearity in their corresponding ranges, with correlation coefficients over 0.99. The average recoveries of straightforward ranged from 78.13% to 110.9%, while RSD ranged from 1.3% to 16.9%, albeit poor purification was observed. The recovery yield from solid phase extraction was between 67.75% and 103.08% with RSD value from 0.8% to 14.0%, which met the requirements of trace determination, this method has good precision and stability. These results could be employed to other Traditional Chinese Medicines (TCMs) in detecting prohibited pesticide residues.

The Association between the Bisphenols Residues in Amniotic Fluid and Fetal Abnormalities in Polish Pregnant Women—Its Potential Clinical Application

The present study aimed to investigate the relationship between the concentrations of bisphenols residues in the amniotic fluid (AF) samples collected during amniocentesis and fetal chromosomal abnormalities in pregnant women. A total of 33 pregnant Polish women aged between 24 and 44 years, and screened to detect high risk for chromosomal defects in the first trimester, were included in this study. Samples were collected from these patients during routine diagnostic and treatment procedures at mid-gestation. The concentrations of various bisphenols residues in the samples were determined by liquid chromatography coupled with triple quadrupole tandem mass spectrometry (LC-ESI-QqQ-MS/MS). Residues of eight analytes (BPS, BPF, BPA, BPAF, BADGE, BADGE•2H2O, BADGE•H2O•HCl and BADGE•2HCl) were detected in amniotic fluid samples in the range 0.69 ng/mL to 3.38 ng/mL. Fetuses with chromosomal abnormalities showed a slightly higher frequency of occurrence of selected bisphenols residues in the AF samples collected between 15-26 weeks of pregnancies. Finally, the proposed method was applied in the simultaneous determination of several endocrine-disrupting chemicals from bisphenol group in 33 human AF samples. BADGE•H2O•HCl has been identified in the AF samples taken from women older than average in the examined group. The number of detected compounds has been significant for the following analytes: BPS, BPAF, BADGE•H2O•HCl and BADGE. The proposed method may be an attractive alternative for application in large-scale human biomonitoring studies.

A fast and simple extraction method for analysing levoglucosan and its isomers in sediments by ion chromatography tandem mass spectrometry.

The ability to trace current and past biomass burning events is important for understanding the links between human activity, fire frequency, and climate. One method of tracing biomass burning is to measure the concentrations of certain monosaccharides anhydrides (MAs), specifically levoglucosan (LEV) and its isomers, mannosan (MAN) and galactosan (GAL), which are products of cellulose and hemicellulose pyrolysis. This work presents a simple extraction method allowing for the rapid, sensitive, and selective determination of MAs in sediments. MAs detection was performed using suppressed ion chromatography with electrospray - triple-stage quadrupole tandem mass spectrometry (IC-TSQ-MS). The extraction method involves ultrasound probe sonication using water as the solvent. Extraction time, amplitude, and sonication mode were optimised. Recoveries higher than 86% for all MAs tested were achieved by applying 70% amplitude in continuous mode for 60 s. Analytical performance of the method included instrumental LODs of 0.10, 0.12 and 0.50 μg L-1 for LEV, MAN and GAL, respectively. No carryover issues, no matrix effect and no co-elution of targeted MAs with other sugars likely present in sediments samples were observed. The developed extraction method was further validated by the analysis of LEV and MAN in NIST® 1649b urban dust reference material and the resulting concentrations were in excellent agreement with previously reported values. MAs quantification in 70 lake sediment samples were carried out with concentrations found to range from 0.009 to 0.390 μg g-1 for LEV and from 0.009 to 0.194 μg g-1 for MAN. Plotting MAs concentrations versus approximate sediment age allowed the reconstruction of recent fire events impacting two locations in the Central Highlands of Tasmania, Australia.

Rapid simultaneous determination of 7 fat-soluble vitamins in human serum by ultra high performance liquid chromatography tandem mass spectrometry.

Accurate detection of vitamins is critically important for clinical diagnosis, metabolomics and epidemiological studies. However, the amounts of different vitamins vary dramatically in human serum. It is a challenge to achieve simultaneous detection of multiple vitamins rapidly. Herein, we developed and validated a sensitive and specific method using ultra high-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) for simultaneous quantification of 7 fat-soluble vitamins (FSVs) across their physiological concentrations in serum for the first time, which was subjected to protein precipitation, liquid-liquid extraction to an organic phase, evaporation to dryness and reconstitution with acetonitrile. In the present procedure, retinol (vitamin A), ergocalciferol (25-OH-D2), cholecalciferol (25-OH-D3), α-tocopherol (vitamin E), phylloquinone (vitamin K1), menatetrenone-4 (MK-4), and menaquinone-7 (MK-7) were detected in one analytical procedure for the first time within 5.0 min by triple quadrupole tandem mass spectrometry. The limit of quantification (LOQ) for vitamin A was 10.0 ng mL-1, LOQs for 25-OH-D2 and 25-OH-D3 were 1.0 ng mL-1, LOQ for vitamin E was 100.0 ng mL-1, and LOQs for vitamin K1, MK-4 and MK-7 were 0.10 ng mL-1, respectively, with a correlation (R2) of 0.995-0.999. Recoveries ranged from 80.5% to 118.5% and the intra-day and inter-day coefficients of variance (CVs) were 0.72-8.89% and 3.2-9.0% respectively. The method was validated according to the European Medicines Agency (EMA) and U.S. Food and Drug guidelines and C62-A on bioanalytical methods, and was used for clinical routine determination.

A burst of fenoterol excretion during the recovery of a weight loss protocol

Fenoterol is a sympathomimetic β2 receptor agonist primarily used as a bronchodilator. Due to its sympathomimetic actions, the World Anti-Doping Agency (WADA) has banned it. Multiple acute weight loss protocols (WLP) are used by Olympic athletes for sports that segregate athletes by weight; these generally involve caloric and water deprivation combined with heat exposure. Athletes use WLP before weigh-in, then transition to different body acute weight regain protocols (WRP) before competitions. Here, we studied the pharmacokinetics of fenoterol under WLP conditions: energetic dietary restriction, decreased water intake, and exposure to a dry sauna (80 ± 2 °C), followed by a WRP. Five elite-level female judo athletes participated in the study. Four received fenoterol (200 μg; n = 2 or 400 μg; n = 2), while one was a control receiving placebo under identical conditions. We measured excretion of the fenoterol parent molecule and presented qualitative data of its sulfated metabolite using QqQ tandem quadrupole mass spectrometry for 118 h. The fenoterol parent appeared earlier in urine than did its conjugated metabolite; excretion profiles were similar among all subjects. The centers of mass for fenoterol parent curves were (time, fenoterol): athlete A (10.9, 7.3); athlete B (9.2, 27.3); athlete C (8.5, 6.9); athlete D (9.7, 5.0). After initiating WRP, we observed a burst in urinary fenoterol excretion once in complete decay. This trend was observed for all four athletes who received fenoterol. Our results suggest that during hypohydration, some of the unmetabolized fenoterol accumulates in tissues, then is released during rehydration. These findings can be important for detecting fenoterol use in athletes.

Plasma pharmacokinetics and pharmacodynamic effects of the 2-benzylbenzimidazole synthetic opioid, isotonitazene, in male rats

Isotonitazene is an illicit synthetic opioid associated with many intoxications and fatalities. Recent studies show that isotonitazene is a potent µ-opioid receptor (MOR) agonist in vitro, but little information is available about its in vivo effects. The aims of the present study were to investigate the pharmacokinetics of isotonitazene in rats, and relate pharmacokinetic parameters to pharmacodynamic effects. Isotonitazene and its metabolites were identified and quantified by liquid chromatography tandem quadrupole mass spectrometry (LC-QQQ-MS). Male Sprague-Dawley rats with jugular catheters and subcutaneous (s.c.) temperature transponders received isotonitazene (3, 10, 30µg/kg, s.c.) or its vehicle. Blood samples were drawn at 15, 30, 60, 120, and 240min post-injection, and plasma was assayed using LC-QQQ-MS. At each blood draw, body temperature, catalepsy scores, and hot plate latencies were recorded. Maximum plasma concentrations of isotonitazene rose in parallel with increasing dose (range 0.2-9.8ng/mL) and half-life ranged from 23.4 to 63.3min. The metabolites 4'-hydroxy nitazene and N-desethyl isotonitazene were detected, and plasma concentrations were below the limit of quantitation (0.5ng/mL) but above the limit of detection (0.1ng/mL). Isotonitazene produced antinociception (ED50 = 4.22µg/kg), catalepsy-like symptoms (ED50 = 8.68µg/kg), and hypothermia (only at 30µg/kg) that were significantly correlated with concentrations of isotonitazene. Radioligand binding in rat brain tissue revealed that isotonitazene displays nM affinity for MOR (Ki = 15.8nM), while the N-desethyl metabolite shows even greater affinity (Ki = 2.2nM). In summary, isotonitazene is a potent MOR agonist whose pharmacodynamic effects are related to circulating concentrations of the parent drug. The high potency of isotonitazene portends substantial risk to users who are exposed to the drug.

Association between antibiotic exposure and the risk of infertility in women of childbearing age: A case-control study

BackgroundBased on self-report questionnaires, two previous epidemiological studies investigated the association between the exposure of women to antibiotics and their fertility. However, biomonitoring studies on low-dose antibiotic exposure, mainly from food and water, and its relation to the risk of infertility are missing. MethodsBased on a case-control study design, 302 women with infertility (144 primary infertility, 158 secondary infertility) and 302 women with normal fertility, all aged 20–49 years, were recruited from Anhui Province, China, in 2020 and 2021. A total of 41 common antibiotics and two antibiotic metabolites in urine samples were determined by liquid chromatography–triple quadrupole tandem mass spectrometry (LC-QqQ-MS/MS). ResultsTwenty-eight antibiotics with detection rates from 10% to 100% in both cases (median concentration: ∼2.294 ng/mL) and controls (∼1.596 ng/mL) were included in the analysis. Logistic regression analysis revealed that after controlling for confounding factors, high concentrations of eight individual antibiotics (sulfamethoxazole, sulfaclozine, sulfamonomethoxine, penicillin G, chlorotetracycline, ofloxacin, norfloxacin, and cyadox) and four antibiotic classes (sulfonamides, tetracyclines, quinoxalines, and veterinary antibiotics) were related to a high risk of female infertility, with odds ratios (ORs) ranging from 1.30 to 2.86, except for chlorotetracycline (OR = 6.34), while another nine individual antibiotics (sulfamethazine, azithromycin, cefaclor, amoxicillin, oxytetracycline, pefloxacin, sarafloxacin, enrofloxacin, and florfenicol) and classes of chloramphenicol analogs and human antibiotics were related to a reduced risk of infertility, with ORs ranging from 0.70 to 0.20. Based on restricted cubic spline models after controlling for confounding factors, we observed that the relationship between all of the above protective antibiotics and infertility was nonlinear: A certain concentration could reduce the risk of female infertility while exceeding a safe dose could increase the risk of infertility. ConclusionThese results provide preliminary evidence that the effects of antibiotics on female fertility vary based on the active ingredient and usage and imply the importance of exposure dose. Future studies are needed to verify these results by controlling for multiple confounding factors.