Gas Chromatography-triple Quadrupole Mass Spectrometry Research Articles

Association of tricarboxylic acid cycle related-metabolites with hypertension in older adults: a community-based cross-sectional study.

Hypertension is still a common chronic disease worldwide and seriously affects human health. Aim of this study was to investigate the association between tricarboxylic acid (TCA) cycle-related metabolites and hypertension in older adults. A total of 1127 community-dwelling older adults were included in this cross-sectional analysis, of whom 609 were assigned to the hypertension group and 518 to the no-hypertension group. Plasma concentrations of 8 TCA cycle-related metabolites (citrate, cis-aconitate, isocitrate, 2-oxoglutarate, succinate, maleate, fumarate, and malate) were determined by gas chromatography-triple quadrupole mass spectrometry. Multivariate logistic regression was used to assess the association between these metabolites and hypertension risk. After adjustment for covariates, we found that the increased plasma concentrations of 2-oxoglutarate and malate were significantly associated with hypertension. These two associations remained unchanged after using the false discovery rate (FDR)-adjustment method (both FDR-adjusted P-trend <0.05). In stratified analysis, these two associations were not modified by overweight, physical activity, and current drinking (all P-interaction >0.05). In the multivariate diagnostic model, the inclusion of these two metabolites modestly and significantly improved the diagnosis of hypertension (AUC = 0.64, 95% CI: 0.60-0.67). These results indicated that plasma 2-oxoglutarate and malate might be the candidate metabolic markers of hypertension among older adults. However, further longitudinal and experimental studies are necessary to confirm this finding.

Occurrence Characteristics and Health Risk Assessment of Organophosphate Esters in Tap Water of Shanghai

To explore the occurrence characteristics and health risk levels of the new pollutants organophosphate esters （OPEs） in tap water in Shanghai, based on the water supply areas of the Qingcaosha Reservoir, Chenhang Reservoir, Dongfeng Xisha Reservoir, and Upstream Huangpu River water sources, a total of 52 large shopping malls in Shanghai were selected as tap water sampling sites. Solid phase extraction and gas chromatography-triple quadrupole mass spectrometry were used to determine eight types of OPEs in tap water from shopping malls, including three types of chlorinated OPEs, two types of alkyl OPEs, and three types of aryl OPEs. On this basis, the health risk assessment of the substances with high detection frequency and concentration was carried out. The results showed that six types of OPEs were generally detected, and the average levels of eight types of OPEs in tap water collected in summer and winter were 64.3 ng·L-1 and 60.5 ng·L-1, respectively. The concentration levels and detection rates of different types of OPEs in tap water followed the order of： chlorinated OPEs &gt; alkyl OPEs &gt; aryl OPEs. From the perspective of water sources, the average concentration of OPEs in tap water with Upstream Huangpu River water sources as the water source was the highest （132 ng·L-1 in summer and 170 ng·L-1 in winter）, and OPEs in tap water with Dongfeng Xisha Reservoir as the water source was the lowest （25.1 ng·L-1 in summer and 6.62 ng·L-1 in winter）. The average concentration of chlorinated OPEs in summer （62.1 ng·L-1） was higher than that in winter （53.9 ng·L-1）. Based on the reference dose of OPEs, there were no health risks to people of all ages through drinking water exposure. However, the OPE exposure in tap water of Shanghai was higher compared with that of other countries and regions, which requires further attention and research.

A direct immersion-solid-phase microextraction method for the automated determination of 3- to 6-ring polycyclic aromatic hydrocarbons in saliva by gas-chromatography-tandem mass spectrometry

This work presents a novel method for the analysis of polycyclic aromatic hydrocarbons (PAHs) in saliva samples using solid phase microextraction (SPME) coupled with gas chromatography-triple quadrupole mass spectrometry (GC-QqQ-MS). The protocol utilizes the latest commercially available overcoated fiber (PDMS/DVB/PDMS) for direct immersion extraction of the target analytes, enabling the determination of thirteen PAHs, including low-volatile compounds. The SPME extraction method was optimized using a central composite design (CCD). The evaluation of the fiber coating's robustness over time demonstrated excellent extraction performance with no significant degradation. The validation procedure confirmed good performance for all parameters, with LOQ values (100 ng/L for ten analytes and 500 ng/L for three analytes) comparable to other chromatographic methods. The environmental impact of the protocol was objectively assessed using two recently proposed metrics: the Green Analytical Procedure Index (GAPI) and the Analytical Greenness metric for sample preparation (AGREEprep). Both metrics indicated good overall environmental friendliness, with AGREEprep providing a satisfactory comprehensive score despite the use of highly impactful instrumentation. These characteristics make the developed method suitable for routine analysis in environmental and epidemiological monitoring.

Impact of salinity on PAH and halogenated PAH contamination and risks during the pickling of Chinese pickles

In this study, solid-phase extraction coupled with gas chromatography–triple quadrupole mass spectrometry was used for analyzing PAHs and XPAHs in pickles. The concentrations were 43.0±3.9 μg/kg for PAH24 (including EPA PAH 16 and EU PAH15+1) and 0.52±0.07 μg/kg for XPAH18 (including 11 chlorinated PAHs and 7 brominated PAHs) in commercially available xuecai, and 28.3±8.7 μg/kg for PAH24 and 0.25±0.11 μg/kg for XPAH18 in laboratory-pickled radish. Throughout the pickling process, concentrations of PAHs generally decreased, while XPAHs in xuecai and chlorinated PAHs (ClPAHs) in radish initially increased before declining. The elevated ClPAH levels in fermented radish compared to their unfermented counterparts, along with the newly formed 1-chlorinated pyrene in xuecai, highlighted the generation of ClPAHs during pickling. At lower salinity levels, the greater reduction in concentrations of PAHs corresponds with the largest increase in ClPAHs, suggesting potential chlorination of some PAHs into ClPAHs via microbial activity. Although concentrations of ClPAHs rose after pickling, the toxic equivalent quotients of PAH42 (including PAH24 and XPAH18) in pickles after fermentation were lower than those in both unfermented and fermenting samples, indicating that mature pickles did not increase the overall toxicity risk associated with PAHs and XPAHs.

Advancing Lung Cancer Diagnosis through NH2-MON-SPME-GC-MS/MS: Enhanced Sensitivity in Aldehyde Biomarker Detection from Exhaled Breath.

The sensitive detection of trace biomarkers in exhaled breath for lung cancer diagnosis represents a critical area of research in life analytical chemistry, with profound implications for early disease detection, therapeutic intervention, and prognosis monitoring. Despite its potential, the analytical process faces significant challenges due to the ultratrace levels of disease biomarkers present and the complex, high-humidity composition of exhaled breath. This study introduces a highly sensitive method for detecting aldehyde biomarkers in exhaled breath by integrating the use of amino-functionalized microporous organic networks (NH2-MON) as a solid-phase microextraction (SPME) fiber coating with gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS) analysis. The method innovatively combines sample collection and extraction, achieving a dual-step enrichment process that significantly enhances both the enrichment efficiency and reproducibility of biomarker detection while effectively mitigating the interference caused by water vapor in exhaled breath. The NH2-MON, utilized as an SPME fiber coating, demonstrates exceptional enrichment capacity for five key aldehyde biomarkers, facilitating the development of a highly sensitive detection approach for these biomarkers in exhaled breath. Compared to previously reported methods, the proposed technique exhibits significantly lower limits of quantification, ranging from 0.77 to 11.89 pg mL-1, and achieves substantially higher enrichment factors, ranging from 9156- to 35723-fold. The practicality and feasibility of the method were validated through the analysis of exhaled breath samples from lung cancer patients, underscoring its potential application in the early diagnosis and monitoring of lung cancer.

Enrichment characteristics of polycyclic aromatic hydrocarbons in coal gangue of the Huaibei Coalfield, China

Coal gangue, a by-product of coal mining, deteriorates and oxidizes, causing environmental pollution. Despite extensive research on polycyclic aromatic hydrocarbon (PAHs) pollution in soil, aerosols, and water, studies on PAHs in coal gangue remain limited. This study aimed to fill this research gap by analyzing gangue samples from three areas in Huaibei. Sixteen priority parent polycyclic aromatic hydrocarbons (16PAHs) and alkyl polycyclic aromatic hydrocarbons (aPAHs) in the samples were analyzed qualitatively and quantitatively via gas chromatography-triple quadrupole mass spectrometry. The results showed that PAHs existed naturally in coal gangue. The aPAHs concentration of multiple samples from the same area (587.88 ng/g, 2972.73 ng/g, and 13528.29 ng/g from Liuqiao, Suntan, and Tongting, respectively) was higher than the 16PAHs concentration (528.79 ng/g, 570.16 ng/g, and 2818.79 ng/g from Liuqiao, Suntan, and Tongting, respectively). Among the 39 samples, the aPAHs concentration after weathering was 7732.78 ng/g, which was higher than the value in the fresh state of 4765.43 ng/g. 16PAHs with low ring number were dominant in the fresh state, but aPAHs with high ring number were dominant after weathering. The diagnostic ratios revealed that traditional diagnostic ratios may confuse sources of PAHs and that gangue should be considered as a single class of source materials. Additionally, there was no significant difference in the ratio between the weathered and fresh state. TEQBaP analysis showed that there was a certain environmental risk in the area and that TEQBaP(weathered) > TEQBaP(fresh). Therefore, the pollution attributable to PAHs in coal gangue, especially weathered gangue, warrants attention.

Effects of Naphtho[2,1-a]pyrene Exposure on CYP1A1 Expression: An in Vivo and in Vitro Mechanistic Study Exploring the Role of Posttranscriptional Modification.

Currently, many emerging polycyclic aromatic hydrocarbons (PAHs) have been found to be widely present in the environment. However, little has been reported about their toxicity, particularly in relation to CYP1A1. This study aimed to explore the toxicity of naphtho[2,1-a]pyrene (N21aP) and elucidate the mechanism underlying N21aP-induced expression of CYP1A1. The concentration and sources of N21aP were detected and analyzed by gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS) and diagnostic ratio analysis. Then the effects of CYP1A1 on the toxicity of N21aP were conducted in male wild-type (WT) and Cyp1a1 knockout mice exposed to N21aP (0.02, 0.2, and ) through intratracheal instillation. Further, the aryl hydrocarbon receptor (AhR) pathway was examined through luciferase and chromatin immunoprecipitation (ChIP) assays. -methyladenosine () modification levels were measured on global RNA and specifically on CYP1A1 mRNA using dot blotting and methylated RNA immunoprecipitation-quantitative real-time polymerase chain reaction (MeRIP qRT-PCR), with validation by inhibitors, DAA and SAH. sites on CYP1A1 were identified by bioinformatics and luciferase assays, and CYP1A1 mRNA's interaction with IGF2BP3 was confirmed by RNA pull-down, luciferase, and RNA binding protein immunoprecipitation (RIP) assays. N21aP was of the same environmental origin as benzo[a]pyrene (BaP) but was more stably present in the environment. N21aP could be metabolically activated by CYP1A1 to produce epoxides, causing DNA damage and further leading to lung inflammation. Importantly, in addition to the classical AhR pathway (i.e., BaP), N21aP also induced CYP1A1 expression with a posttranscriptional modification of in CYP1A1 mRNA via the METTL14-IGF2BP3-CYP1A1 axis. Specifically, in the two recognition sites of METTL14 on the CYP1A1 mRNA transcript (position at 2700 and 5218), a methylation site (position at 5218) in the 3'-untranslated region (UTR) was recognized by IGF2BP3, enhanced the stability of CYP1A1 mRNA, and finally resulted in an increase in CYP1A1 expression. This study systematically demonstrated that in addition to AhR-mediated transcriptional regulation, N21aP, had a new additional mechanism of -mediated posttranscriptional modification, jointly contributing to CYP1A1 expression. Given that PAHs are the metabolic substrates of CYP1A1, this study not only helps to understand the significance of environment-genetic interactions for the toxicity of PAHs but also helps to better understand the health risks of the emerging PAHs at environmental exposure levels. https://doi.org/10.1289/EHP14055.

Solid phase extraction coupled with gas chromatography-triple quadrupole mass spectrometry for the rapid and simultaneous determination of forty-nine parent and halogenated polycyclic aromatic hydrocarbons in human serum

Halogenated polycyclic aromatic hydrocarbons (H-PAHs) are the emerging organic pollutants in environment, which are ubiquitous in the atmosphere, soil and water. Some H-PAH congeners have been proven to have dioxin-like toxicity. However, the research on the human internal exposure of H-PAHs is still limited. A simple and efficient analytical method is essential for the study of human internal exposure, so a method for the rapid and simultaneous determination of 16 polycyclic aromatic hydrocarbons (PAHs) and 33 H-PAHs in human serum was established in this study. After 1.0 mL serum was extracted with ethyl acetate/acetonitrile (1:4) solution containing 1 % formic acid, samples were purified by Captiva EMR-Lipid solid phase extraction column, and then determined by gas chromatography tandem triple quadrupole mass spectrometer (GC-MS/MS). The results showed that the recoveries of PAHs and H-PAHs ranged from 71.2 % to 119 % and 68.8 % to 121 %, respectively. When 1.0 mL of serum sample is used, the method detection limit of PAHs and H-PAHs is 0.001–0.314 ng/mL. The method is simple and efficient, and suitable for the simultaneous determination of trace PAHs and H-PAHs in human serum. High concentrations of chlorinated polycyclic aromatic hydrocarbons were detected in pooled serum, of which 1,5-dichloranthracene was the main contributor congener, with a concentration of 204–328 ng/g lipid, which deserved more attention.

Covalent organic framework-functionalized magnetic MXene nanocomposite for efficient pre-concentration and detection of organophosphorus and organochlorine pesticides in tea samples before gas chromatography–triple quadrupole mass spectrometry analysis

In this study, a hydrophobic covalent organic framework-functionalized magnetic composite (CoFe2O4@Ti3C2@TAPB−TFTA) with a high specific area with 1,3,5-tris(4-aminophenyl)benzene (TAPB) and 2,3,5,6-tetrafluoroterephthalaldehyde (TFTA) was designed and synthesized through Schiff base reaction. An efficient magnetic solid-phase extraction method was established and combined with gas chromatography–triple quadrupole mass spectrometry to sensitively determine 10 organochlorine and organophosphorus pesticides in tea samples. The established method exhibited good linearity in the range of 0.05–120 μg/L and had low limits of detection (0.013–0.018 μg/L). The method was evaluated with tea samples, and the spiked recoveries of pesticides in different tea samples reached satisfactory values of 85.7–96.8%. Moreover, the adsorption of pesticides was spontaneous and followed Redlich–Peterson isotherm and pseudo-second-order kinetic models. These results demonstrate the sensitivity, effectiveness, and reliability of the proposed method for monitoring organochlorine and organophosphorus pesticides in tea samples, providing a preliminary basis for researchers to reasonably design adsorbents for the efficient extraction of pesticides.

Use of nitrogen markers to assess source rock paleodepositional environment of the Candeias (Recôncavo Basin) and Barreirinha (Amazonas Basin) formations

In this study nitrogen markers (N-markers) were employed to evaluate the depositional paleoenvironment of the Candeias and Barreirinha Formations, Recôncavo and Amazonas Basins, respectively. Towards this end, twenty-one N-markers from carbazole (CA), benzocarbazole (BCA), indole (IND), acridine (ACR), and quinolone (QUIN) classes were determined by highly selective and sensitive gas chromatography-triple quadrupole mass spectrometry (GC–MS/MS). Twenty-four (24) samples was collected in vertical sections of outcrops of the Candeias Formation and of the Barreirinha Formation. The N-markers were efficient in evaluating distinctions and similarities between the source rocks and were able to define the origin and input of organic matter, the depositional paleoenvironment conditions of the samples. The samples from the Recôncavo Basin presented low concentrations of CA, methyl carbazole (MCA), and dimethyl carbazole (DMCA), and high concentrations of QUIN and 4-methyl quinoline (4-MQUIN), indicating a lacustrine environment. Samples from the Amazonas Basin present high concentrations of CA, MCA, DMCA, 2,4-dimethyl quinoline (2,4-DMQUIN), benzo[c]quinoline (B[c]QUIN), and ACR, typical of the marine environment. Although the formations are from different paleoenvironments, the organic matter input is similar. The proportions of the 1-, 2- and 4-methyl carbazole (1-MCA, 2-MCA, and 4-MCA), in addition to the low values for the 4-MCA/2-MCA ratio, allowed to affirm that algal input was predominant in the Candeias and Barreirinha formations. The relative concentration of DMCA and of the B[b]CA isomer also indicate the supply of terrigenous material for both formations. BCA concentrations were affected by the conditions of depositional paleoenvironment. Samples deposited under redox conditions presented low concentrations of BCA, and those deposited in oxidizing environments had higher amounts.

New findings on the risk of hypertension from organophosphorus exposure under different glycemic statuses: The key role of lipids?

Background and objectiveConsidering the widespread use of organophosphorus pesticides (OPs) and the global prevalence of hypertension (HTN), as well as studies indicating that different glycemic statuses may respond differently to the biological effects of OPs. Therefore, this study, based on the Henan rural cohort, aims to investigate the association between OPs exposure and HTN, and further explores whether lipids mediate these associations. MethodsWe measured the plasma levels of OPs in 2730 participants under different glycemic statuses using gas chromatography-triple quadrupole mass spectrometry (GC–MS/MS). A generalized linear model, Quantile g-computation (QGC), adaptive elastic net (AENET), and Bayesian kernel machine regression (BKMR) models were used to assess the impact of OPs exposure on HTN, with least absolute shrinkage and selection operator (LASSO) penalty regression identifying main OPs. Mediation models were used to evaluate the intermediary role of blood lipids in the OPs-HTN relationship. ResultsThe detection rates for all OPs were high, ranging from 76.35 % to 99.17 %. In the normal glucose tolerance (NGT) population, single exposure models indicated that malathion and phenthoate were associated with an increased incidence of HTN (P-FDR < 0.05), with corresponding odds ratios (ORs) and 95 % confidence intervals (CIs) of 1.624 (1.167,2.260) and 1.290 (1.072,1.553), respectively. QGC demonstrated a positive association between OP mixtures and HTN, with malathion and phenthoate being the primary contributors. Additionally, the AENET model's Exposure Response Score (ERS) suggested that the risk of HTN increases with higher ERS (P < 0.001). Furthermore, BKMR revealed that co-exposure to OPs increases HTN risk, with phenthoate having a significant impact. Furthermore, triglycerides (TG) mediated 6.55 % of the association between phenthoate and HTN. However, no association was observed in the impaired fasting glucose (IFG) and type 2 diabetes mellitus (T2DM) populations. ConclusionsOur findings suggest that in the NGT population, OPs may significantly contribute to the development of HTN, proposing TG as a potential novel target for HTN prevention.

Rapid determination of 15 N-nitrosamines in air-dried yak meat using one-step QuEChERS-gas chromatography-triple quadrupole mass spectrometry

A method based on gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS) coupled with one-step QuEChERS technique was developed for the simultaneous determination of 15 N-nitrosamines in air-dried yak meat. The hydration volume, extraction solvent, extracting salt, and cleaning material were optimized according to the characteristics of the N-nitrosamines and sample matrix. The optimized conditions were as follows: 10 mL of purified water for sample hydration, acetonitrile as the extraction solvent for the sample after hydration, 4.0 g of anhydrous MgSO4 and 1.0 g of NaCl as extracting salts, 500 mg of MgSO4+25 mg of C18+50 mg of PSA as cleaning materials. Favorable recoveries of the 15 N-nitrosamines were obtained when the extraction solution was incompletely dried. Thus, the final extract was dried to below 0.5 mL under a mild nitrogen stream and then redissolved to 0.5 mL with acetonitrile. After filtration, 200 μL of the sample was transferred to an autosampler vial for GC-MS/MS analysis. The 15 N-nitrosamines were determined using GC-MS/MS on a DB-HeavyWAX column (30 m×0.25 mm×0.25 μm) with an electron impact ion source in multiple-reaction monitoring (MRM) mode, and quantified using an external standard method. Under the optimized experimental conditions, the results showed that the calibration curves exhibited good linearities for the 15 N-nitrosamines, with correlation coefficients (r2) greater than 0.9990. The limits of detection (LODs) and the limits of quantification (LOQs) ranged from 0.05 to 0.20 μg/kg and from 0.10 to 0.50 μg/kg, respectively. At spiked levels of 1LOQ, 2LOQ, and 10LOQ, the average recoveries were 79.4%-102.1%, 80.6%-109.5%, and 83.0%-110.6%, respectively, and the relative standard deviations were in the range of 0.8%-16.0%. The low matrix effects of the 15 N-nitrosamines indicated the high sensitivity of the proposed method. The method was applied to detect representative commercial air-dried yak meat samples obtained using different processing techniques. Seven N-nitrosamines, including N-nitrosodimethylamine, N-nitrosodiisobutylamine, N-nitrosodibutylamine, N-methyl-N-phenylnitrous amide, N-ethyl-N-nitrosoaniline, N-nitrosopyrrolidine, and N-nitrosodiphenylamine were detected in all samples. The average contents of the seven N-nitrosamines was 0.08-20.18 μg/kg. The detection rates and average contents of the N-nitrosamines in cooked air-dried yak meat samples were higher than those in traditional raw air-dried yak meat samples. Compared with the manual QuEChERS method, the one-step QuEChERS method developed integrated the extraction and clean-up procedures into one single run, and the detection efficiency was considerably improved. The developed method is simple, rapid, highly sensitive, and insusceptible to human errors. Thus, it is useful for the determination of N-nitrosamines in air-dried yak meat and can be extended to the qualitative and quantitative analysis of N-nitrosamines in other meat products. It also provides method support and a data reference for the general determination of N-nitrosamines, which is of great significance for food safety.

High enrichment and sensitive measurement of seventeen phthalates in beverages with metal organic framework functionalized magnetic MXene nanocomposite based on magnetic solid phase extraction prior to gas chromatography-triple quadrupole mass spectrometry

Phthalates (PAEs) are typical plasticizers, and widely used in various products. Because of their toxic effects such as carcinogenicity and endocrine disruption, they have become one of the most important public health hazards. It is vital to establish reliable methods for sensitively measuring PAEs at trace levels in the environment. In present study, a new magnetic metal organic framework functionalized MXene composite was designed (CoFe2O4@Ti3C2@MIL101(Cr)), in which NH2-MIL101(Cr) was successfully modified onto the surface of aldehyde-functionalized magnetic titanium carbide by Schiff base reaction. The prepared magnetic composite was used as the adsorbent for magnetic solid-phase extraction (MSPE) in combination with gas chromatography–triple quadrupole mass spectrometry (GC-MS/MS) for high-performance enrichment and sensitive measurement of seventeen PAEs. CoFe2O4@Ti3C2@MIL101(Cr) had favorable adsorption ability for PAEs, the adsorption of PAEs was multilayered and non-uniform, and followed the pseudo-second-order kinetic model and Redlich-Peterson isotherm model. Moreover, the results revealed that the lower temperature was more beneficial for the extraction of PAEs. The factors influencing the enrichment efficiencies of PAEs were investigated. Under the optimal experimental conditions, the constructed method exhibited prominent linearity over concentration range of 0.01–40 μg L−1, and the limits of detection (LODs) were very low over range of 0.003–0.018 μg L−1. The extraction efficiencies of seventeen PAEs were ranged from 44.2 % to 104 %. The established method was validated for determining PAEs in the different beverages, and DIBP (0.19 μg L−1) and DBP (0.44 μg L−1) were successfully detected in tea drinks, and the spiked recoveries of seventeen PAEs in real samples were in the range of 86.9 −100.2 %, with standard deviations less than 5.8 %. The enrichment factors were between 71 and 166. In short, the proposed method earned prominent sensitivity and high feasibility, and could be a credible, and valuable alternative for monitoring PAEs in the future.

Integration of lipidomics and metabolomics reveals plasma and urinary profiles associated with pediatric Mycoplasma pneumoniae infections and its severity.

Mycoplasma pneumoniae is a significant contributor to lower respiratory infections in children. However, the lipidomics and metabolics bases of childhood M. pneumoniae infections remain unclear. In this study, lipidomics and metabolomics analyses were conducted using UHPLC-LTQ-Orbitrap XL mass spectrometry and gas chromatography-triple quadrupole mass spectrometry on plasma (n = 65) and urine (n = 65) samples. MS-DIAL software, in combination with LipidBlast and Fiehn BinBase DB, identified 163 lipids and 104 metabolites in plasma samples, as well as 208 metabolites in urine samples. Perturbed lipid species (adjusted p < 0.05) were observed, including lysophosphatidylethanolamines, phosphatidylinositols, phosphatidylcholines, phosphatidylethanol amines, and triglycerides. Additionally, differential metabolites (adjusted p < 0.05) exhibited associations with amino acid metabolism, nucleotide metabolism, and energy metabolism. Thirteen plasma metabolites, namely l-hydroxyproline, 3-phosphoglycerate, citric acid, creatine, inosine, ribitol, α tocopherol, cholesterol, cystine, serine, uric acid, tagatose, and glycine, showed significant associations with disease severity (p < 0.05) and exhibited distinct separation patterns in M. pneumoniae-infected bronchitis and pneumonia, with an area under the curve of 0.927. Nine of them exhibited either positive or negative correlations with neutrophil or lymphocyte percentages. These findings indicated significant systemic metabolic shifts in childhood M. pneumoniae infections, offering valuable insights into the associated metabolic alterations and their relationship with disease severity.

Comparison on volatile components between Artemisiae Verlotori Folium and Artemisiae Argyi Folium based on GC-MS and chemometrics

Artemisiae Argyi Folium is commonly used in clinical practice. Artemisiae Verlotori Folium, the dried leaves of Artemisia verlotorum, is often used as a folk substitute for Artemisiae Argyi Folium in Lingnan area. In this study, gas chromatography-triple quadrupole mass spectrometry(GC-MS) was used to detect the volatile oil components of 27 samples of Artemisiae Verlotori Folium and 13 samples of Artemisiae Argyi Folium, and the volatile components were compared between the two species. The internal standard method was combined with multi-reaction monitoring mode(MRM) to determine the content of six major volatile components. Hierarchical clustering analysis(HCA) and orthogonal partial least squares-discriminant analysis(OPLS-DA) were carried out for the content data. The results showed that the Artemisiae Argyi Folium samples had higher content and more abundant volatile oils than the Artemisiae Verlotori Folium samples. Artemisiae Argyi Folium mainly had the components with lower boiling points, while Artemisiae Verlotori Folium mainly had the components with higher boiling points. Terpenoids were the main volatile components in Artemisiae Verlotori Folium(mainly sesquiterpenoids) and Artemisiae Argyi Folium(monoterpenoids). In addition, Artemisiae Argyi Folium had higher content of oxygen-containing derivatives than Artemisiae Verlotori Folium. Furthermore, the stoichiometric analysis showed that the two species could be distinguished by both HCA and OPLS-DA, indicating that the volatile components of the two were significantly different. This study can provide a scientific basis for the quality evaluation and data support for the local rational application of Artemisiae Verlotori Folium in Lingnan.

High-throughput screening of 54 alternative plasticizers in sesame oil using gas chromatography-quadrupole time-of-flight mass spectrometry

Restrictions on the use of phthalates have led to the wide use of alternative plasticizers (APs) such as organophosphate, adipate, citrate, and sebacate. However, because plasticizers combine with polymers in plastic products via unstable noncovalent bonds, they can easily migrate out of these products, causing environmental pollution. In particular, their migration out of food packaging, containers, and other food-contact materials and into food has raised great concerns. Toxicological studies have shown that APs contain potentially toxic substances that can affect endocrine functions and cause neurotoxicity, genotoxicity, and other adverse effects. Thus, their potential risks to food should not be underestimated. Sesame oil is a necessity in daily cooking. The results of risk monitoring in recent years have indicated that sesame oil often contains phthalates in excess of the standard limits. However, the potential risks of APs in sesame oil have not yet been reported. Some common detection methods for APs include gas chromatography-mass spectrometry, gas chromatography-triple quadrupole mass spectrometry, and liquid chromatography-triple quadrupole mass spectrometry. Unfortunately, these methods use low-resolution mass spectrometry and are limited by the resolution, scan rate, and analysis mode. Gas chromatography-quadrupole time-of-flight mass spectrometry (GC-Q-TOF/MS) has the advantages of high resolution, sensitivity, and analysis speed. In full-scan mode, GC-Q-TOF/MS can accurately collect the full-spectrum mass number of target compounds with low content levels in complex substrates, thereby realizing efficient screening and quantitative analysis. It shows outstanding advantages in the trace analysis of pesticide residues and pollutants. Furthermore, it features strong qualitative and high screening abilities. Establishment of a personal compound database and library (PCDL) addresses limitations in the number of compounds that can be measured and enables the rapid identification of targets without the use of standard products. In addition, increasing the number of targets for synchronous screening enables the retrospective analysis of new targets. In this study, a method based on GC-Q-TOF/MS was developed for the determination of 54 APs in sesame oil. The samples were extracted with acetonitrile and purified using a PSA/silica solid-phase extraction column. The mass-spectral information of the samples was then collected by GC-Q-TOF/MS in full-scan mode, and the 54 APs were searched using an established high-resolution mass-spectrum database to simultaneously achieve the broad-spectrum screening, qualitative identification, and quantitative analysis of multiple targets. The effects of different extraction solvents and purification methods on sample extraction and purification were compared. The accuracy of the screening results was improved by optimizing the GC-separation conditions, quality-extraction window, retention-time deviation, and other screening parameters. The screening detection limits (SDLs) of the 54 APs ranged from 0.01 to 0.02 mg/kg; specifically, the SDL of 41 compounds was 0.01 mg/kg and that of 13 compounds were 0.02 mg/kg. The limits of quantification were in the range of 0.02-0.04 mg/kg. A total of 80 sesame-oil samples were rapidly screened using this method under optimal conditions. Five APs were identified from the 80 sesame-oil samples and quantitatively analyzed using the matrix-matched external-standard method. The results of this quantitative methodology showed that the five APs had good linear relationships in the range of 0.01-0.2 mg/L, with all correlation coefficients greater than 0.99. The accuracy and precision of the method were verified using a standard recovery test with blank sesame-oil samples. Under the three standard levels of 0.04, 0.08, and 0.2 mg/kg, the recoveries of the five APs ranged from 71.3% to 97.8%, and the relative standard deviations (RSDs) ranged from 0.4% to 6.1%(n=6). The developed method is fast, accurate, sensitive, and has high throughput. Thus, it can realize the efficient screening, qualitative identification, and quantitative analysis of the 54 APs in sesame oil and provides a potential solution for the monitoring of other contaminants in food.

Direct extraction with acetonitrile of hemp seed oil for the analysis of pesticides by using comprehensive two-dimensional gas chromatography-triple quadrupole mass spectrometry

The method herein described involves a rapid and limited-volume (0.5 mL of acetonitrile) solvent-extraction sample preparation process, for pesticide determination in hemp seed oil. The extraction method was characterized by the absence of both clean-up or pre-concentration steps. The extracts were directly analyzed through cryogenic-modulation comprehensive two-dimensional gas chromatography coupled to triple quadrupole mass spectrometry. The novelty characterizing the present research [compared to a previous one (Arena et al., 2023)] is related to the extension of the number of pesticides (97), and to the investigation of a more challenging matrix, contained in a vegetable oil of increasing interest among consumers.Linearity, limits of detection and quantification, accuracy, precision, recovery, and matrix effect were measured. Particular emphasis was devoted to the matrix effect, with the co-extracted matrix amount defined. Three international regulations (Canada, California, Europe) were considered, and the obtained limits of quantification were found to be too high in five (Canada) and twelve (Europe) cases, for a total number of 15 pesticides.The analysis of ten commercial samples showed the presence of seven pesticide residues in four of them, at concentration levels ranging from 0.02 to 0.98 mg kg−1, with most over the regulation residue limits.

Blood Levels of Organochlorine Contaminants Mixtures and Cardiovascular Disease

Cardiovascular toxic effects derived from high exposures to individual organochlorine compounds are well documented. However, there is no evidence on low but continuous exposure to combined organochlorine compounds in the general population. To evaluate the association of combined exposure to several organochlorine compounds, including organochlorine pesticides and polychlorinated biphenyls, with incident cardiovascular disease (CVD) in the general population. This prospective nested case-control study included data from 2 cohorts: the Swedish Mammography Cohort-Clinical (SMC-C) and the Cohort of 60-Year-Olds (60YO), with matched case-control pairs based on age, sex, and sample date. Baseline blood sampling occurred from November 2003 to September 2009 (SMC-C) and from August 1997 to March 1999 (60YO), with follow-up through December 2017 (SMC-C) and December 2014 (60YO). Participants with myocardial infarction or ischemic stroke were matched with controls for composite CVD evaluation. Data were analyzed from September 2020 to May 2023. A total of 25 organochlorine compounds were measured in blood at baseline by gas chromatography-triple quadrupole mass spectrometry. For 7 compounds, more than 75% of the samples were lower than the limit of detection and not included. Incident cases of primary myocardial infarction and ischemic stroke were ascertained via linkage to the National Patient Register (International Statistical Classification of Diseases and Related Health Problems, Tenth Revision codes I21 and I63). The quantile-based g-computation method was used to estimate the association between the combined exposure to several organochlorine compounds and composite CVD. Of 1528 included participants, 1024 (67.0%) were female, and the mean (SD) age was 72 (7.0) years in the SMC-C and 61 (0.1) years in the 60YO. The odds ratio of composite CVD was 1.71 (95% CI, 1.11-2.64) per 1-quartile increment of total organochlorine compounds mixture. Organochlorinated pesticides were the largest contributors, and β-hexachlorocyclohexane and transnonachlor had the highest impact. Most of the outcome was not explained by disturbances in the main cardiometabolic risk factors, ie, high body mass index, hypertension, lipid alteration, or diabetes. In this prospective nested case-control study, participants with higher exposures to organochlorines had an increased probability of experiencing a cardiovascular event, the major cause of death worldwide. Measures may be required to reduce these exposures.

A protocol based on solid phase microextraction -gas chromatography-tandem mass spectrometry for the monitoring of parabens and bisphenols in human saliva

The herein presented work aims to the development of an easy method for the quantitative determination of parabens and bisphenols in human salivabased on the use of methyl chloroformate as a derivatizing agent, followed by solid-phase microextraction (SPME) and gas chromatography-triple quadrupole mass spectrometry (GC-QqQ-MS) analysis with selected reaction monitoring (SRM). Using multivariate analysis, two derivatization strategies were compared and optimized, demonstrating that the use of methyl chloroformate led to better sensitivity than the classical derivatization by acetic anhydride. Good performance in the sorption process of the derivatized target analytes was obtained using the most recent commercialized overcoated fiber (PDMS/DVB/PDMS). The validation procedure of the final protocol led to satisfactory results in terms of linearity, limit of quantitation, accuracy, and precision. All parabens were quantified from 10 ng/L using the developed method, except for methylparaben, which was quantified from 100 ng/L along with all bisphenols. Intra- and inter-day accuracy and intra- and inter-day precision can be considered satisfactory for all analytes (values between 73% and 118%), except for the inter-day accuracy of BPF. Quite good results also in terms of matrix effect were obtained for the target compounds (range 71% to 118%, RSD% less than 13.6%), except for BPA at the middle concentration and MeP at the lowest concentration. The greenness of the method was evaluated and the results indicated that our approach is more eco-friendly than previously published methods. Based on its characteristics, the presented method can be considered a suitable approach to determine parabens and bisphenols in routine analysis for biomonitoring purposes.

Pesticide Residues in Mandarins: Three-Year Monitoring Results.

The demand of plant production product use has increased because of the current system of citrus production, which prioritizes high agricultural yields. Therefore, the monitoring of pesticide residues in citrus fruits and other agricultural products and their impacts on human health and food security are of great concern. This study aims to determine multi-class pesticides including highly polar residues in satsuma mandarins. A total of 226 mandarin samples were collected over three consecutive harvesting years from 2019 to 2021 in the Izmir region of Turkey. Targeted compounds included pesticides and metabolites with European Union (EU) regulatory levels, plus other non-approved residues and highly polar compounds. The residues excluding highly polar substances were analyzed by applying the quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction and liquid chromatography-triple quadrupole mass spectrometry (LC-MS/MS) determination for 434 analytes and gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS) determination for 71 analytes. For six highly polar pesticides, sample preparation was based on Quick Polar Pesticides (QuPPe) extraction. The polar residues were determined by LC-MS/MS using internal standards. Forty different residues, including two highly polar substances, were recorded in mandarin samples through three harvesting years. In 8.4% of the samples, no quantifiable residues were detected, whereas 207 samples contained at least one residue. The maximum residue level (MRL) exceedances were recorded for 22.1% of the samples. The two most frequently found pesticides were phosphonic acid and spirotetramat, with an incidence rate of 48.7% and 46.5%, respectively. The concentration of phosphonic acid and spirotetramat in mandarin samples varied from 0.026 to 39.386 mg kg-1 and from 0.010 to 1.485 mg kg-1, respectively. The results will enable researchers and regulatory authorities to assess the extent of pesticide presence, identify potential risks, and take necessary measures to ensure the safety of satsuma mandarins for consumers.