High Performance Liquid Chromatography-triple Quadrupole Research Articles

Ji-Ni-De-Xie ameliorates type 2 diabetes mellitus by modulating the bile acids metabolism and FXR/FGF15 signaling pathway

Introduction: Ji-Ni-De-Xie (JNDX) is a traditional herbal preparation in China. It is widely used to treat type 2 diabetes mellitus (T2DM) in traditional Tibetan medicine system. However, its antidiabetic mechanisms have not been elucidated. The aim of this study is to elucidate the underlying mechanism of JNDX on bile acids (BAs) metabolism and FXR/FGF15 signaling pathway in T2DM rats.Methods: High-performance liquid chromatography-triple quadrupole mass spectrometry (HPLC-QQQ-MS) and UPLC-Q-Exactive Orbitrap MS technology were used to identify the constituents in JNDX. High-fat diet (HFD) combined with streptozotocin (45 mg∙kg−1) (STZ) was used to establish a T2DM rat model, and the levels of fasting blood-glucose (FBG), glycosylated serum protein (GSP), homeostasis model assessment of insulin resistance (HOMA-IR), LPS, TNF-α, IL-1β, IL-6, TG, TC, LDL-C, HDL-C, and insulin sensitivity index (ISI) were measured to evaluate the anti-diabetic activity of JNDX. In addition, metagenomic analysis was performed to detect changes in gut microbiota. The metabolic profile of BAs was analyzed by HPLC-QQQ-MS. Moreover, the protein and mRNA expressions of FXR and FGF15 in the colon and the protein expressions of FGF15 and CYP7A1 in the liver of T2DM rats were measured by western blot and RT-qPCR.Results: A total of 12 constituents were identified by HPLC-QQQ-MS in JNDX. Furthermore, 45 chemical components in serum were identified from JNDX via UPLC-Q-Exactive Orbitrap MS technology, including 22 prototype components and 23 metabolites. Using a T2DM rat model, we found that JNDX (0.083, 0.165 and 0.33 g/kg) reduced the levels of FBG, GSP, HOMA-IR, LPS, TNF-α, IL-1β, IL-6, TG, TC, and LDL-C, and increased ISI and HDL-C levels in T2DM rats. Metagenomic results demonstrated that JNDX treatment effectively improved gut microbiota dysbiosis, including altering some bacteria (e.g., Streptococcus and Bacteroides) associated with BAs metabolism. Additionally, JNDX improved BAs disorder in T2DM rats, especially significantly increasing cholic acid (CA) levels and decreasing ursodeoxycholic acid (UDCA) levels. Moreover, the protein and mRNA expressions of FXR and FGF15 of T2DM rats were significantly increased, while the expression of CYP7A1 protein in the liver was markedly inhibited by JNDX.Discussion: JNDX can effectively improve insulin resistance, hyperglycemia, hyperlipidemia, and inflammation in T2DM rats. The mechanism is related to its regulation of BAs metabolism and activation of FXR/FGF15 signaling pathway.

Prenatal organophosphate esters exposure and neurodevelopment trajectory in infancy: Evidence from the Shanghai Maternal-Child Pairs Cohort

BackgroundConcerns remain about the neurotoxic properties of the ubiquitous organophosphate esters (OPEs), the replacement of the toxicant polybrominated diphenyl ethers. ObjectivesWe examined the associations of prenatal exposure to OPEs and their mixtures with early-life neurodevelopment trajectories. MethodsTotally 1276 mother-child pairs were recruited from the Shanghai Maternal-Child Pairs Cohort. A high-performance liquid chromatography-triple quadrupole mass spectrometer was used to measure the levels of 7 OPEs in cord serum. Ages and Stages Questionnaires was used to examine children's neuropsychological development at 2, 6, 12, and 24 months of age. Group-based trajectory models were applied to derive the neurodevelopmental trajectories. Multiple linear regression and logistic regression model were performed to assess the relationships between OPEs exposure and neurodevelopment and trajectories. Mixtures for widely detected OPEs (n = 4) were investigated using quantile-based g-computation. ResultsTributyl phosphate (TBP), tris (2-butoxy ethyl) phosphate (TBEP), tris(1,3-dichloro-2-propyl) phosphate (TDCPP), and 2-ethylhexyl diphenyl phosphate (EHDPP), had detection rates >50 %. TDCPP had the highest median concentration (1.02 μg/L) in cord serum. EHDPP concentrations were negatively associated with scores in most domains at 12 months of age, with effect values (β) ranging from −1.89 to −0.57. EHDPP could negatively affect the total ASQ (OR = 1.07, 95 % CI: 1, 1.15) and gross-motor (OR = 1.09, 95 % CI: 1.02, 1.17) trajectory in infancy. Joint exposure to OPEs was associated with decreased scores in the total ASQ, gross-motor, fine-motor and problem-solving domain of 12-month-old infants, with β ranging from −5.93 to −1.25. In addition, the qgcomp models indicated significant positive associations between the concentrations of OPEs mixtures and risks of the persistently low group of the total ASQ, gross-motor and fine-motor development in early childhood. The impact of OPEs was more pronounced in boys. DiscussionOur findings suggested OPEs, especially EHDPP, had a persistently negative effect on neurodevelopment during the first 2 years.

Simultaneous determination of six benzodiazepine sedatives residue in aquatic products by high performance liquid chromatography-triple quadrupole mass spectrometry

To establish a method for the simultaneous determination of 6 benzodiazepine sedatives residue in aquatic products by high performance liquid chromatography-triple quadrupole mass spectrometry. The samples were extracted with acetonitrile and purified by C_(18 )solid phase extraction column. The sample solution was separated by Waters ACQUITY UPLC BEH C_(18 )column(2.1 mm×50 mm, 1.7 μm) using 0.1% formic acid and methanol as mobile phase for gradient elution, determined in multiple reaction monitoring mode and quantified by internal standard method. Six benzodiazepine sedatives had a good linear relationship in the range of 1.0-50.0 μg/L with r>0.9990, the limits of detection and limits of quantification were 0.3 and 1.0 μg/kg. Average recoveries for the analytes at 3 spiked levels ranged from 74.2%-108.0% with relative standard deviations of 1.1%-6.7%(n=6). The method is simple, rapid, sensitive and accurate, which is suitable for simultaneous determination of 6 benzodiazepine sedatives residue in aquatic products.

Characteristics and Ecological Risk Assessment of Pharmaceutical Active Compounds in Guangdong Province

Pharmaceutically active compounds(PhACs) have become a class of new pollutants in the environment after extensive production and use of PhACs in China. To investigate the pollution characteristics of PhACs in Guangdong Province, raw sewage was collected from 186 sewage treatment plants in 21 cities, including 178 townships and administrative districts in Guangdong Province. The pollution levels of ten typical PhACs in influent water of sewage treatment plants were analyzed using automatic solid phase extraction and high performance liquid chromatography-triple quadrupole mass spectrometry. The spatial distribution characteristics of PhACs in Guangdong Province were fully revealed, and the potential ecological risks of PhACs were evaluated. The results showed that PhACs were detected in all wastewater plants, and the mass concentration of PhACs ranged from 21.00 to 9558.25 ng·L-1. Metoprolo, acetaminophen, bezafibrate, and caffeine were the main pollutants. In terms of spatial distribution, the average mass concentration of ΣPhACs in various regions of Guangdong Province was in the following order:Pearl River Delta>North Guangdong>East Guangdong≈West Guangdong. When the mass concentration of ΣPhACs was over 2500 ng·L-1 in the influent water of sewage treatment plants, the concentration of PhACs in effluent was estimated according to the sewage disposal technology. The ecological risk of PhACs was carried out based on the effluent. The results revealed that the ecological risk of PhACs was low in Guangdong Province, and the risk of bezafibrate was moderate in the cities of Shaoguan, Jiangmen, and Shenzhen. The highest ecological risk of ΣPhACs was located in Shaoguan.

Determination of oxylipins and their precursors in breast milk by solid phase extraction-ultra high performance liquid chromatography-triple quadrupole tandem mass spectrometry

Oxylipins and their precursors (long-chain polyunsaturated fatty acids, LCPUFAs) are key intercellular signaling molecules influencing the inflammatory response. Each oxylipin has pro- and/or anti-inflammatory effects, and the relative abundance of different oxylipins can alter the inflammatory balance, making it important to clarify the oxylipin profile of breast milk for optimal infant health. The extraction, identification, and simultaneous quantification of oxylipins in breast milk are challenging due to the structural similarity, limited stability, and the low endogenous concentration of oxylipins and the complex matrix of breast milk. This study aimed to develop a solid phase extraction-ultra high performance liquid chromatography-triple quadrupole tandem mass spectrometry (SPE-UPLC-MS/MS) method for the comprehensive and specific quantification of oxylipins and their precursors in breast milk. The LC conditions (including column, mobile phase, and gradient conditions) and SPE procedure (including SPE cartridges, elution solvent, and elution volume) were optimized to achieve accurate quantification and better analyte recovery. A single 18-minute chromatographic run allows for the quantification of 20 oxylipins and 5 PUFAs. The results showed good linearity (R2 > 0.99) over the concentration range of 2 to 100 ng/mL, with the instrument detection limits ranging from 0.01 to 0.90 ng/mL for oxylipins and 0.02 to 0.59 ng/mL for PUFAs. The method is rapid, sensitive, and reproducible (RSD ≤ 10%) and is suitable for the quantitative analysis of oxylipins and their precursors in infant formula samples.

Determination of glycidyl fatty acid esters in edible vegetable oils by HPLC-ESI-QQQ-MS/MS combined with cryo-degreasing tandem dispersive solid-phase extraction

Glycidyl fatty acid esters (GEs) have been identified as food contaminants that can form during the processing and heating of edible oils. Their widespread occurrence raises potential concerns for consumers. This study aimed to develop a simple and effective analytical method for molecular recognition using mass spectrometry fragmentation patterns. Furthermore, it sought to simultaneously and quantitatively determine five common GEs in highly complex fatty matrices (oils) using high-performance liquid chromatography-triple quadrupole tandem mass spectrometry (HPLC-ESI-QQQ-MS/MS). An extraction method using acetonitrile was used, and the purification of the extract was optimized using cryo-degreasing-tandem dispersive solid-phase extraction (d-SPE) to eliminate fatty interferents. The method validation yielded recoveries ranging from 81.17% to 109.28% and the method precision was < 10.00%. The limits of quantification ranged from 0.08 to 0.21 ng/g, which is below the current legal limits. This approach may play a crucial role in ensuring food safety.

Relationship between one-carbon metabolism and fetal growth in twins: A cohort study.

We investigated the associations of one-carbon metabolism (OCM)-related metabolites, including choline, betaine, dimethylglycine (DMG), and methionine with fetal growth of twins. This hospital-based cohort study included dichorionic twin gestations. Blood samples were collected at a median of 14.7 weeks of gestation. Blood plasma metabolite levels were measured using high-performance liquid chromatography-triple quadrupole mass spectrometry. Generalized estimating equations and mixed effects models were used to explore associations between plasma metabolite levels and fetal growth. In total, 115 women with dichorionic diamniotic pregnancies were included. The maternal plasma DMG level was negatively correlated with fetal birth weight (β = -43.5, 95% confidence interval [CI] = -74.1 to -12.8, p < .05) and head circumference (β = -0.23, 95% CI = -0.39 to -0.07, p < .05). Other metabolites were not significantly associated with birth weight, body length, head circumference (HC), or chest circumference. Analysis of the relationships between plasma metabolite levels and fetal biological parameters on ultrasound revealed that the maternal choline level was negatively correlated with fetal abdominal circumference (AC) (β = -0.12, 95% CI = 0.24 to -0.004, p < .05); the maternal DMG level was negatively correlated with fetal AC (β = -0.17, 95% CI = 0.28-0.07, p < .05), femur length (β = 0.02, 95% CI = 0.04-0.003, p < .05), and estimated fetal weight (β = 26.4, 95% CI = -41.6 to -11.2, p < .05), but not with HC. The maternal methionine level was negatively correlated with HC (β = -0.08, 95% CI = -0.14 to -0.02, p < .05). The plasma level of the OCM-related metabolite DMG during the second trimester was negatively correlated with fetal intrauterine growth and birth weight. However, further studies with larger samples are needed.

Comparison of Chemical and Sensory Profiles between Cabernet Sauvignon and Marselan Dry Red Wines in China.

The differences in chemical and sensory characteristics between Marselan and Cabernet Sauvignon in China were investigated with gas chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography-triple quadrupole mass spectrometry (HPLC-QqQ-MS/MS), combined with color parameters and sensory data. The paired t-test results showed that terpenoids, higher alcohols, and aliphatic lactones were significantly different according to the grape variety. Meanwhile, terpenoids could be considered as marker aroma compounds to distinguish Marselan wines from Cabernet Sauvignon, which could explain the distinct floral note in Marselan wines. The mean concentrations of the mv-vsol, mv-vgol, mv-vcol, mvC-vgol, mv-v(e)cat, mvC-v(e)cat, mv-di(e)cat, and cafA were higher in Marselan wines than Cabernet Sauvignon wines, and these compounds might confer Marselan wines with a deeper color, more red hue, and higher tannin quality. The phenolic profiles of Marselan and Cabernet Sauvignon wines were influenced by the winemaking process, mitigating the varietal differences. As for sensory evaluation, the intensities of herbaceous, oak, and astringency of Cabernet Sauvignon were more pronounced than Marselan, whereas the Marselan wines were characterized by a high color intensity and more redness, together with floral, sweet, and roasted sweet potato attributes, and tannin roughness.

Associations of prenatal PFAS exposure and early childhood neurodevelopment: Evidence from the Shanghai Maternal-Child Pairs Cohort

Epidemiological data on the effects of perfluoroalkyl and polyfluoroalkyl substances (PFAS) on infant neurodevelopment trajectories are far from being sufficiently addressed. In this study, 1285 mother–child pairs were recruited during 2016–2017. A high-performance liquid chromatography-triple quadrupole mass spectrometer was used to measure 16 PFAS levels in cord serum. Ages and Stages Questionnaires were used to examine children's neurodevelopment at 2, 6, 12, and 24 months of age. Group-based trajectory models were applied to derive the neurodevelopmental trajectories. Children with relatively low scores from 2 to 24 months were classified into a low-score group and were used as a risk group in each domain. Multiple linear regression, logistic regression, and quantile-based g-computation were performed to assess associations of single or mixture PFAS exposures with neurodevelopment and trajectories. Perfluorooctane sulphonate (PFOS), perfluorooctanoic acid (PFOA), perfluorohexanesulfonic acid (PFHxS), and 6:2 chlorinated polyfluorooctane ether sulfonate (6:2Cl-PFESA) were detected in over 90 % samples. PFOA had the highest concentration (median: 4.61 μg/L). Each ln-unit (μg/L) increase of PFAS (e.g., PFOA, PFOS, PFHxS, 6:2Cl-PFESA) was associated with poor scores of communication domain at 6 months, with the effect size ranging from −0.69 to −0.44. PFOS (OR: 1.14, (1.03, 1.26), PFDA (OR:1.08, (1.02, 1.15)), PFHxS (OR:1.31, (1.12, 1.56)), and 6:2Cl-PFESA (OR:1.08, (1.00, 1.16)) were associated with an increased risk of being in the low-score group in the early childhood communication domain's trajectory. Each mixture quartile increment was associated with a 1.60 (−2.76, −0.45) decrease in communication domain scores of 6-month-old infants, and the mixture effect was mainly attributed to PFOS. Each mixture quartile increase was associated with a 1.23-fold (1.03, 1.46) risk of being in the low-score group of the communication domain, and the mixture effect was mainly attributed to PFOS. In conclusion, PFAS and their mixtures might adversely affect childhood neurodevelopment. The gender-specific associations existed in the above associations.

Preparation of chemically modified cellulose filter paper for extracting amphetamine-type stimulants from water followed by HPLC-MS/MS determination

A novel chemically modified cellulose filter paper (CMCFP) was prepared by a two-step reaction of esterification and thiol-ene click reaction with cellulose filter paper (CFP). The paper based CMCFP extraction material was used to extract amphetamine-type stimulants (ATSs) from water, followed by high-performance liquid chromatography-triple quadrupole mass spectrometry (HPLC-MS/MS) determination. The FT-IR, XPS, and SEM characterizations showed that the modifiers of 3-mercaptopropionic acid and sodium 4-vinylbenzenesulfonate were successfully covalently grafted onto the CFP. The recovery rates of the 7 target ATSs by CMCFP extraction had a maximum value in the pH range of 4.0–7.0. The kinetic experiments indicated that the main adsorption mechanism of CMCFP for ATSs was chemisorption. The adsorption capacity was greater than 37 ng·cm-2. Surface water and wastewater spike experiments revealed that the determination of 7 ATSs by CMCFP extraction coupled with HPLC-MS/MS method had recoveries of 80.5–116%. Meanwhile, the detection limits were 0.40–3.03 ng·L-1, and the linear range was 20–1000 ng·L-1 with relative standard deviations of 2.2–11%. The CMCFP extraction material obtained in this study is environmentally friendly and economical, and has the same good extraction efficiency as the commercial solid phase extraction cartridges.

Simultaneous determination of twenty-nine active compounds in fuzhengjiedu granules by HPLC-QQQ-MS/MS

As an empirical medicine of traditional Chinese medicine, Fuzhengjiedu Granules have shown an effect against COVID-19 in clinical and inflammatory animal models. It is formulated with eight herbs, including Aconiti Lateralis Radix Praeparata, Zingiberis Rhizoma, Glycyrrhizae Radix Et Rhizoma, Lonicerae Japonicae Flos, Gleditsiae Spina, Fici Radix, Pogostemonis Herba, and Citri Reticulatae Pericarpium. This study established a high-performance liquid chromatography-triple quadrupole mass spectrometry (HPLC-QQQ-MS/MS) method by simultaneously determining 29 active compounds in the granules with significant content differences. Separation by gradient elution using acetonitrile and water (0.1% formic acid) as mobile phases was performed on a Waters Acquilty UPLC T3 column (2.1 mm × 100 mm, 1.7 μm). A triple quadrupole mass spectrometer, operating in positive and negative ionization modes, was used for multiple reaction monitoring to detect the 29 compounds. All calibration curves showed good linear regression (r2 > 0.998). RSDs of precision, reproducibility, and stability of active compounds were all lower than 5.0%. The recovery rates were 95.4–104.9%, with RSDs< 5.0%. This method was successfully used to analyze the samples, and the results showed that 26 representative active components from 8 herbs were detected in the granules. While aconitine, mesaconitine, and hypaconitine were not detected, indicating that the existing samples were safe. The granules had the maximum and minimum content of hesperidin (27.3 ± 0.375 mg/g) and benzoylaconine (38.2 ± 0.759 ng/g). To conclude, a fast, accurate, sensitive, and reliable HPLC-QQQ-MS/MS method was established, which can simultaneously detect 29 active compounds that have a considerable difference in the content of Fuzhengjiedu Granules. This study can be used to control the quality and safety of Fuzhengjiedu Granules and provide a basis and guarantee for further experimental research and clinical application.

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.

Amino-functionalized metal–organic frameworks for efficient solid-phase microextraction of perfluoroalkyl acids in environmental water

The ubiquitous occurrence of perfluoroalkyl acids (PFAAs) in environmental water has drawn much attention due to their high persistence and bioavailability. However, it is difficult for the traditional adsorbents to extract PFAAs because of their unique hydrophobic and oleophobic properties. In this study, an amino-functionalized ZIF-8 (NH2-ZIF-8) was fabricated and used as the coating materials of the solid-phase microextraction fiber for the determination of PFAAs in water samples. The introduction of the amino group improved the extraction performance of PFAAs via electrostatic interaction and hydrogen bond, which exhibited better extraction efficiencies than those of ZIF-8 coated fiber and commercial fibers. The extraction efficiencies of PFAAs decreased with the increase of pH values, indicating that electrostatic interaction between the carboxylic acid group of PFAAs and the amino group of NH2-ZIF-8 played a dominating role in enrichment. The fabricated fiber coupled with high-performance liquid chromatography-triple quadrupole mass spectrometry (HPLC-MS/MS) was used for the detection of PFAAs in water samples, with a wide linear range (1–5000 ng L−1), low limits of detection (0.15–0.75 ng L−1), and good repeatability and reproducibility (1.9%-15.5%). The established method has been successfully applied in environmental water analysis, which provides a practical method for the determination of PFAAs in a convenient manner.

Determination of 42 antibiotic residues in seven categories in water using large volume direct injection by ultra high performance liquid chromatography-triple quadrupole mass spectrometry

抗生素作为新型有机污染物在自然水体中被频繁检出,检出种类多且含量水平低,为了实现更加快速、全面、准确的高通量分析,研究开发了一种利用大体积直接进样测定水中7大类(磺胺类、林可酰胺类、喹诺酮类、大环内酯类、四环素类、头孢类及氯霉素类)42种抗生素的超高效液相色谱-三重四极杆质谱法。水样经0.22 μm滤膜过滤,加入Na2EDTA并调节pH值至6.0~8.0,加入内标混匀后,采用Phenomenex Kinetex C18柱(50 mm×30 mm, 2.6 μm),以0.1%(v/v)甲酸水溶液-乙腈作为流动相进行梯度洗脱,质谱智能化分时间段-多反应选择离子监测(Schedule-MRM)模式进行检测。42种抗生素在相关线性范围内线性良好(r=0.9949~0.9995),回收率为80.1%~125%,相对标准偏差为0.8%~12.2%,方法检出限为0.015~3.561 ng/L。将该方法应用于10份水源水和5份末梢水的检测,结果显示在42种抗生素中,12种抗生素有检出,包括磺胺类、大环内酯类、林可酰胺类和氯霉素类,其在水源水中的检出率达100%;林可霉素和氯霉素是检出质量浓度最高的两种抗生素,它们的质量浓度范围分别为3.83~13.8和24.8~33.6 ng/L。该方法从检出限和回收率两方面与标准方法和文献报道进行了比较,检出限及回收率均满足要求。该方法与传统前处理方法相比具有简单、快速、绿色、精密度高、准确度高、消耗样品量小的优点,能用于地表水、地下水、末梢水等较为洁净水体中42种痕量水平的抗生素测定。

The Screening Approaches for 34 Common Drugs and Metabolites in Biological Samples by Liquid Chromatography Orbital Trap Mass Spectrometry

To establish a high-performance liquid chromatography orbital trap mass spectrometry (HPLC-Obitrap MS) method for screening 34 common drugs and metabolites in biological samples. The target analytes in urine and blood samples were extracted with ethyl acetate, concentrated by nitrogen blowing and redissolved. The hair samples were washed with water and acetone, dried and cut into bits of about 1 mm, and then crushed in a freezing grinder. The analytes were extracted with methanol, and after filtration, the filtrate was used for instrumental analysis. Hypersil Gold PFP (2.1 mm×100 mm, 3 µm) column was used for chromatographic separation. Methanol and 5 mmol/L ammonium acetate solution were used as mobile phase with gradient elution at a flow rate of 400 μL/min. Mass spectrometry was done by electrospray positive and negative ion alternation mode. The data were collected using Full MS and Full MS/dd-MS2 mode. Xcalibur 4.0 software was used to control instruments and to collect data, and TraceFinder 3.3 was used for screening and identification. The method's detection limits for 34 drugs and their metabolites in blood, urine and hair samples were 3.30-10700 ng/L, 4.43-5440 ng/L, 0.0350-4.21 μg/kg, respectively. The intra-day and inter-day precisions of the spiked samples at the levels of 5.0, 10, and 20 μg/L were 3.50%-6.00% and 4.18%-9.90%, respectively. A total of 1125 biological samples of urine, blood and hair were collected and screened. The results showed that 96.7% of the drug users were taking a single drug, while 3.3% were mixed drug users. The main types of drug of abuse were methamphetamine (75.8%), heroin (18.5%), ketamine (2.4%) and other drugs (3.3%), and 87.9% of the positive samples were from male users. Compared with the results of high-performance liquid chromatography triple quadrupole mass spectrometry, this method can be used to identify more types of drugs in one run and to conduct retrospective analysis. The method established in the study is simple and sensitive and is well suited for the screening of common drugs and metabolites in biological samples.

Effect of childhood phthalates exposure on the risk of overweight and obesity: A nested case-control study in China.

There was growing interest in endocrine disrupting chemicals that might have effect on the obesity epidemic, but few studies on the association of phthalates (PAEs) with childhood overweight and obesity in China based on longitudinal cohort study were available, which was the purpose of the present study. A nested case-control study was conducted in a prospective cohort of 2298 children aged 7-13years from October 2017 to October 2020 with five waves visits in Xiamen city, China. A total of 829 children remained in the first wave of follow up with collection of urine for measuring seven PAEs metabolites, including mono-methyl phthalate (MMP), mono-ethyl phthalate (MEP), mono-n-butyl phthalate (MBP), mono-iso-butyl phthalate (MiBP), mono-2-ethylhexyl phthalate (MEHP), mono-2-ethyl-5-oxohexyl phthalate (MEOHP) and mono-2-ethyl-5-hydroxyhexyl phthalate (MEHHP), utilizing ultra high performance liquid chromatography-triple quadrupole mass spectrometry. Overweight and obesity, defined by WHO classifications, were allocated to the cases group, and those of all normal weight and matched cases with normal weight in each wave of follow-up as two control groups. Logistic regression models after adjusting for confounders were utilized to analyze the effect of PAEs on overweight and obesity in children with divided four groups based on the quartile distribution of each and total PAEs concentration. The detection rates of children for each PAEs metabolite were 99.4% for MMP, 99.4% for MEP, 99.8% for MBP, 54.5% for MEHP, 84.4% for MEOHP, 99.9% for MEHHP, and 97.2% for MiBP. The geometric mean of concentrations of PAEs, MMP, MEP, MBP, MEHP, MEHHP, and MiBP were 310.085, 34.658, 9.127, 166.347, 7.043, 3.400, 18.571, and 24.093 (ng/ml), respectively. The total PAEs and seven metabolites concentrations were positively associated with childhood BMI Z-Scores with statistically significant slope rates and correlation coefficients, and were higher in the cases group than those in two controls groups in each wave of follow-up. The PAEs concentrations in the cases group was 5.90 (95%CI: 5.79, 6.01) ng/ml in the first wave of survey, which was higher than those normal controls group (5.68 (95%CI: 5.61, 5.75) ng/ml, P<0.001) and matched controls group (5.72 (95%CI: 5.61, 5.84) ng/ml, P=0.018). The prevalence and ORs of overweight and obesity increased with quartile group of each and total PAEs concentrations accompanying a dose-response relationship. Compared with the quartile1 reference group with lowest total PAEs concentrations, the ORs of overweight and obesity in quartile2, quartile3 and quartile4 group increased gradually and reached at 1.20 (0.74-1.95), 1.49 (0.93-2.38) and 2.22 (1.41-3.48), respectively (Ptrend<0.001). The strength of the associations between PAEs and overweight and obesity was sex-specific in children. Children in China were extensively exposed to PAEs, and the exposure to PAEs during childhood could significantly increase the risk of overweight and obesity with a dose-response relationship, particularly in girls. While limiting the exposure of PAEs products, the determination of exposure limit of plasticizer should be further strengthened.

Observations of Gas-Phase Alkylamines at a Coastal Site in the East Mediterranean Atmosphere

Atmospheric amines are ubiquitous compounds in the atmosphere, having both natural and anthropogenic origin. Recently, they have been identified as important contributors to new particle formation in the atmosphere, but observations of their atmospheric concentrations are scarce. In the present study we introduce the first systematic long-term observations of gas-phase amines measurements in the East Mediterranean atmosphere. Air samples were collected at the Finokalia monitoring station of the University of Crete during a 3.5-year period from January 2013 to July 2016, and analyzed after extraction using a high-performance liquid chromatography triple quadrupole mass spectrometer. The detected alkylamines were the sum of dimethylamine and ethylamine (DMA+EA), trimethylamine (TMA), diethylamine (DEA) and triethylamine (TEA). DMA+EA and TMA were the most abundant alkylamines, with concentrations spanning from the detection limit to 78.0 and 69.8 pptv, and average concentrations of 7.8 ± 12.1 and 7.5 ± 12.4 pptv, respectively. Amines showed pronounced seasonal variability with DMA+EA and TMA concentrations being higher in winter. Statistical analysis of the observations showed different sources for each of the studied amines, except for DMA+ΕA and DEA that appear to have common sources in the region. This analysis points to a marine source of TMA and animal husbandry in the area as a potential source of TEA. None of the alkylamines is correlated with other anthropogenic sources. Furthermore, no clear association was found between the seasonality of NPF events and alkylamines concentrations, while a clear correlation was detected between the seasonality of nucleation mode particle (dp &lt; 25 nm) number concentrations and alkylamine concentrations, indicating that amines may contribute to nucleation mode particles’ production.

Simultaneous determination of triazine herbicides and their metabolites in shellfish by HPLC-MS/MS combined with Q/E-Orbitrap HRMS.

Triazine herbicides are used extensively in agriculture and aquaculture worldwide because of their broad effectiveness in weed control. However, after they are discharged into the sea, they seriously contaminate aquatic ecosystems and threaten aquatic organisms, especially shellfish. Currently, there are no established methods for the detection and confirmation of triazine herbicides and their metabolites in biological matrixes. Hence, the food safety of aquatic products cannot be accurately evaluated, which creates a technical barrier against international aquatic product trade. In this study, for the first time, a method was developed for the analysis and confirmation of seven triazine herbicides and 13 metabolites in shellfish, based on alkaline acetonitrile extraction and neutral Al2O3 cartridge purification coupled with internal standard calibration. Specifically, quantitative and qualitative analysis was conducted using high-performance liquid chromatography-triple quadrupole mass spectrometry (HPLC-MS/MS), and accurate identification was carried out by quadrupole orbitrap high-resolution mass spectrometry (Q/E Orbitrap HRMS). The results showed that target analytes demonstrated good linearity within the corresponding range (R2 > 0.995). The limit of detection and limit of quantitation of the proposed method were 0.1 and 0.3 μg/kg, respectively. The average recoveries of analytes were between 70.0% and 120% when spiked at three levels with blank oyster (Crassostrea gigas) as the matrix, and the relative standard deviations (RSDs) were all less than 12% (n=6). The proposed method was successfully applied for the detection of triazine herbicide residues in oyster samples during actual breeding, and the presence of DIP, HP, DEHA, and other metabolites in positive samples was confirmed by Q/E Orbitrap HRMS. This method exhibits high accuracy, high sensitivity, and good reproducibility. It has promising application prospects in the field of hazard analysis and the positive identification of aquatic products.

A Multidimensional Mass Spectrometry-Based Workflow for De Novo Structural Elucidation of Oligosaccharides from Polysaccharides.

Carbohydrates play essential roles in a variety of biological processes that are dictated by their structures. However, characterization of carbohydrate structures remains extremely difficult and generally unsolved. In this work, a de novo mass spectrometry-based workflow was developed to isolate and structurally elucidate oligosaccharides to provide sequence, monosaccharide compositions, and glycosidic linkage positions. The approach employs liquid chromatography–tandem mass spectrometry (LC–MS/MS)-based methods in a 3-dimensional concept: one high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (HPLC-QTOF MS) analysis for oligosaccharide sequencing and two ultra high performance liquid chromatography-triple quadrupole mass spectrometry (UHPLC-QqQ MS) analyses on fractionated oligosaccharides to determine their monosaccharides and linkages compositions. The workflow was validated by applying the procedure to maltooligosaccharide standards. The approach was then used to determine the structures of oligosaccharides derived from polysaccharide standards and whole food products. The integrated LC–MS workflow will reveal the in-depth structures of oligosaccharides.

Simultaneous Quantification of Four Compounds in Rat Plasma by HPLC-MS/MS and Its Application to Pharmacokinetic Study after Oral Administration of Pomegranate Flowers.

Pomegranate flowers (PFs) were reported to possess various biological activities such as antidiabetic, anti-inflammatory and hepatoprotective activities, and using to treat diabetes. Although chemical constituents and pharmacological activities of PFs have been studied, unfortunately, there was no report on the pharmacokinetic profile of PFs in vivo. In this study, a selective high-performance liquid chromatography triple quadrupole tandem mass spectrometry (HPLC-QQQ-MS/MS) method was developed and validated for simultaneous quantification of four compounds (corilagin, ellagic acid, gallic acid and brevifolincarboxylic acid) in rat plasma after oral administration of PFs. The good linearity concentration ranges for the four analytes were from 2.5 to 3000ng/mL with coefficient value R2 > 0.99 in calibration curves. The intra- and inter-day accuracy of the four analytes was in the range of 85.33-102.50%, with relative standard deviation (RSD) of <14.81%. The stability results showed that accuracy of the four analytes was in the range of 81.88-104.74%, with RSD of <14.86%. The validation method was successfully applied to pharmacokinetic profiles of the four analytes in rats after oral administration of PFs extract. This pharmacokinetic study can provide better understanding to clarify in vivo mechanisms of PFs and may facilitate its further development as therapeutic agent.