The Tijuana River Estuary (TRE) has been a public health hazard and point of contention between the United States and Mexico for decades, with sources of pollution on both sides of the border. The ...goal of our study is to determine the presence and dynamics of chemical contamination in the TRE. We sampled sediment from four TRE locations in the U.S. during stable dry conditions and immediately after a wet weather period. Organic chemicals were initially screened with non-targeted analysis using gas chromatography high-resolution mass spectrometry (GC/HRMS) that tentatively identified 6978 chemicals in the NIST 20 database. These tentative identifications were filtered using the USEPA CompTox database to guide quantitative targeted analysis at detection limits below 1 ng/g dry weight sediment. Quantitative targeted analysis of 152 organic pollutants and 18 inorganic elements via GC/HRMS revealed generally higher concentrations of contaminants in dry weather sediments compared to wet weather sediments. The highest concentrations of all chemical classes were detected at the site closest to the U.S.-Mexico border, followed by an urban area near Imperial Beach, California, U.S. All sites exhibited a mixture of petrogenic and pyrogenic polycyclic aromatic hydrocarbons (PAHs). Current-use pesticides were dominated by pyrethroid insecticides and the thiocarbamate herbicide s-Ethyl dipropylthiocarbamate (EPTC), while the U.S.-banned organochlorine pesticides were dominated by chlordanes, dieldrin, and dichlorodiphenyltrichloroethane (DDT) and its degradation byproducts. Polychlorinated biphenyl (PCB) concentrations were greatest at the site closest to the U.S.-Mexico border but in the low nanogram-per-gram range. Phthalates were only found at the same site, with relatively high concentrations of bis(2-ethylhexyl) phthalate. This study provides positive identification and quantitative concentrations for organic pollutants in TRE sediments. Our data suggest that there are multiple sources of chemical contamination in the estuary, including possible transboundary movement of pollutants from Mexico.
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•PAHs are the most abundant group of chemicals across all sampling sites.•U.S.-banned pesticides were detected at the site closest to the U.S.-Mexico border.•Phthalates, mainly DEHP, were only detected at the site closest to the border.•Upstream dry weather sediments overall contain higher concentrations of pollutants.
COVID-19 pandemic spread rapidly worldwide with unanticipated effects on mental health, lifestyle, stability of economies and societies. Although many research groups have already reported SARS-CoV-2 ...surveillance in untreated wastewater, only few studies evaluated the implications of the pandemic on the use of chemicals by influent wastewater analysis. Wide-scope target and suspect screening were used to monitor the effects of the pandemic on the Greek population through wastewater-based epidemiology. Composite 24 h influent wastewater samples were collected from the wastewater treatment plant of Athens during the first lockdown and analyzed by liquid chromatography mass spectrometry. A wide range of compounds was investigated (11,286), including antipsychotic drugs, illicit drugs, tobacco compounds, food additives, pesticides, biocides, surfactants and industrial chemicals. Mass loads of chemical markers were estimated and compared with the data obtained under non-COVID-19 conditions (campaign 2019). The findings revealed increases in surfactants (+196%), biocides (+152%), cationic quaternary ammonium surfactants (used as surfactants and biocides) (+331%), whereas the most important decreases were estimated for tobacco (−33%) and industrial chemicals (−52%). The introduction of social-restriction measures by the government affected all aspects of life.
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•Findings reflect the effects of pandemic and social distancing.•Wastewater-based epidemiology was used to assess the exposure to various chemicals.•Significant changes in illicit drug consumption were observed.•Surfactants and biocides showed a notable increase 196% and 152%, respectively.•Significant reduction of the industrial chemicals (52%) due to business closure
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•The first paper identifying and quantifying mycotoxins and metabolites in human breastmilk.•QuEChERS–UHPLC–HRMS allowed rapid and reliable quantitative analysis.•The exposure of ...mothers and infants to mycotoxins was evidenced using human milk.
Humans can be exposed to mycotoxins through the food chain. Mycotoxins are mainly found as contaminants in food and could be subsequently excreted via biological fluids such as urine or human breast milk in native or metabolised form. Since breast milk is usually supposed as the only food for new-borns, the occurrence of mycotoxins in thirty-five human milk samples was evaluated by a newly developed method based on QuEChERS extraction and UHPLC–HRMS detection. The method described here allows the detection of target mycotoxins in order to determine the quality of this initial feeding. The method has been fully validated, with recoveries ranging from 64% to 93% and relative standard deviations (RSD, %) being lower than 20%. Using the method described, non-metabolised mycotoxins such as ZEA, NEO, NIV, ENA, ENA1, ENB, ENB1 and metabolites, such as ZEA metabolites, HT-2, DOM and T-2 triol were detected in human milk samples. Results obtained help to estimate the exposure of mothers and infants to mycotoxins. Moreover, to the best of our knowledge, this is the first work describing the simultaneous detection, quantification and screening of mycotoxins and their metabolites in human mature milk.
•“Tranq-dope”, xylazine-adulterated opioids, has caused many overdose deaths in the US.•Xylazine and opioids act in synergy, increasing the lethality of one another.•We report the first fatal case of ...xylazine-adulterated heroin in the EU.•Xylazine and its main metabolite were detected in blood and urine by LC-HRMS/MS.•Xylazine should be strictly controlled by public health authorities and toxicologists.
The number of xylazine-involved overdose deaths tremendously increased from 2019 onwards in the US. This is due to the “tranq-dope” trend consisting in mixing opioids with the sedative to reduce drug manufacturing costs and enhance their effects. In this study, we report the first fatality involving xylazine-adulterated heroin in the EU.
The subject was a 33-year-old Caucasian male with a documented history of drug abuse who was found dead in a public area with puncture marks at the elbow. Peripheral blood and urine were collected at the autopsy and analyzed by liquid chromatography-high-resolution tandem mass spectrometry (LC-HRMS/MS) after protein precipitation.
6-Monoacetylmorphine, total/free morphine, and codeine blood concentrations of 20.3, 236/105, and 38.3 ng/mL, respectively, indicated recent heroin consumption. Methadone blood concentration was below 10 ng/mL. Alprazolam, nordiazepam, and flurazepam blood concentrations were 23.9, 61.4, and 55.0 ng/mL, respectively. Benzoylecgonine blood concentration was below 5 ng/mL. Xylazine blood and urine concentrations were 105 and 72.6 ng/mL, respectively.
The combination of central nervous system depressants, i.e., opioids, benzodiazepines, and xylazine, was the principal cause of death by cardiorespiratory failure. The case was promptly reported to the UE Early Warning System on drugs.
This review summarizes the advances in environmental analysis by liquid chromatography–high-resolution mass spectrometry (LC–HRMS) during the last decade and discusses different aspects of their ...application. LC–HRMS has become a powerful tool for simultaneous quantitative and qualitative analysis of organic pollutants, enabling their quantitation and the search for metabolites and transformation products or the detection of unknown compounds. LC–HRMS provides more information than low-resolution (LR) MS for each sample because it can accurately determine the mass of the molecular ion and its fragment ions if it can be used for MS–MS. Another advantage is that the data can be processed using either target analysis, suspect screening, retrospective analysis, or non-target screening. With the growing popularity and acceptance of HRMS analysis, current guidelines for compound confirmation need to be revised for quantitative and qualitative purposes. Furthermore, new commercial software and user-built libraries are required to mine data in an efficient and comprehensive way. The scope of this critical review is not to provide a comprehensive overview of the many studies performed with LC–HRMS in the field of environmental analysis, but to reveal its advantages and limitations using different workflows.
Gas chromatography coupled to high‐resolution mass spectrometry is a powerful analytical method that combines excellent separation power of gas chromatography with improved identification based on an ...accurate mass measurement. These features designate gas chromatography with high‐resolution mass spectrometry as the first choice for identification and structure elucidation of unknown volatile and semi‐volatile organic compounds. Gas chromatography with high‐resolution mass spectrometry quantitative analyses was previously focused on the determination of dioxins and related compounds using magnetic sector type analyzers, a standing requirement of many international standards. The introduction of a quadrupole high‐resolution time‐of‐flight mass analyzer broadened interest in this method and novel applications were developed, especially for multi‐target screening purposes. This review is focused on the development and the most interesting applications of gas chromatography coupled to high‐resolution mass spectrometry towards analysis of environmental matrices, biological fluids, and food safety since 2010. The main attention is paid to various approaches and applications of gas chromatography coupled to high‐resolution mass spectrometry for non‐target screening to identify contaminants and to characterize the chemical composition of environmental, food, and biological samples. The most interesting quantitative applications, where a significant contribution of gas chromatography with high‐resolution mass spectrometry over the currently used methods is expected, will be discussed as well.
This study presents the validation of a sensitive method for the determination of 6‐nitrodopa, 6‐nitrodopamine, 6‐nitroadrenaline and 6‐cyanodopamine in Krebs–Henseleit solution by LC–MS/MS with ...ESI+. HRMS was used to precisely characterize the structures of the fragment ions. The method was applied to investigate the catecholamine basal release from rabbit isolated atria and ventricles. The atria and ventricles were suspended separately in a 5 ml organ bath containing Krebs–Henseleit solution with ascorbic acid (3 mM), gassed (95%O2/5%CO2) at 37°C for 30 min. Strata‐X 33 μm SPE cartridges were employed for the extraction of the catecholamines and the internal standard 6‐nitrodopamine‐d4. The catecholamines were separated employing a 150 × 3 mm Shim‐pack GIST C18‐AQ (3 mm particle size), placed in an oven at 40°C and perfused by 65% of mobile phase A (MeCN/H2O; 90/10, v/v) + 0.4% CH3COOH and 35% mobile phase B (deionized H2O) + 0.2% CH2O2 at 320 μl/min in isocratic mode. The method was linear at 0.1–20 ng/ml. The method was used to identify for the first‐time basal release of the three nitrocatecholamines mentioned above and a member of a novel class of catecholamines, the cyanocatecholamines.
Database-driven suspect screening has proven to be a useful tool to detect new psychoactive substances (NPS) outside the scope of targeted screening; however, the lack of retention times specific to ...a liquid chromatography (LC) system can result in a large number of false positives. A singular stream-lined, quantitative structure-retention relationship (QSRR)-based retention time prediction model integrating multiple LC systems with different elution conditions is presented using retention time data (n = 1281) from the online crowd-sourced database, HighResNPS. Modelling was performed using an artificial neural network (ANN), specifically a multi-layer perceptron (MLP), using four molecular descriptors and one-hot encoding of categorical labels. Evaluation of test set predictions (n = 193) yielded coefficient of determination (R2) and mean absolute error (MAE) values of 0.942 and 0.583 min, respectively. The model successfully differentiated between LC systems, predicting 54%, 81% and 97% of the test set within ±0.5, ±1 and ±2 min, respectively. Additionally, retention times for an analyte not previously observed by the model were predicted within ±1 min for each LC system. The developed model can be used to predict retention times for all analytes on HighResNPS for each participating laboratory's LC system to further support suspect screening.
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•A retention time prediction model was developed incorporating multiple LC systems.•The model was trained using the retention times of new psychoactive substances.•Retention times were obtained from the crowd-sourced database, HighResNPS.•A singular model demonstrated improved performance over individual models.•The model can be used to predict retention times for unique entries on HighResNPS.
Post-mortem toxicology constantly deals with the research of reliable alternative matrices to be applied in case of highly damaged corpses (such us carbonized, skeletonized, human remains, etc.). ...Teeth represent a promising alternative matrix since dental tissues are endowed by different features, resistance and stability after death.
Since scant literature reported on the pharmacokinetics and mechanism of incorporation of xenobiotics into dental tissues, this pilot research aims to investigate whether in the pulp can be detected the same substances found in blood in drug related death cases. Secondly, the study is addressed to disclose the possible deposit of drugs in dental hard tissues (dentine and/or enamel), thus contributing to reconstruct the drug abuse history (timing, e.g.).
The study experimented with a novel method to separately analyse dental enamel, dentin, and pulp, applied to 10 teeth collected during autopsies of drug-related deaths along with blood and hair samples for classic toxicological analyses. Each tooth was prepared by “pulverization technique” and then analysed by gas chromatography paired with mass spectrometry (GC-MS) and ultra high performance liquid chromatography coupled to high resolution mass spectrometry (UHPLC/HR-MS) for searching cocaine, opiates, and metabolites. The results were then compared with those obtained from blood and hair samples.
Preliminary results demonstrated that teeth differ from any other classic matrix (blood and hairs) since the qualitative correspondence of the detected substances between pulp and blood as well as dental hard tissues and hair suggests that they can be useful in post-mortem evaluation as a unique matrix for both acute and chronic assumptions of drugs. The mechanism of accumulation of substances in mineralized dental tissues emerged the most significant result, being influenced by the type of molecule and the method of assumption. The main limitation of this study is the limited availability of the sample and the absence of anamnestic information of the time, rates and method of drug assumption during life. Further research is necessary to systematically investigate the distribution of different substances within the different tissues of the tooth.
•Post-mortem toxicology deals with reliable alternative matrices.•Teeth represent a promising alternative matrix.•Teeth show the qualitative correspondence of substances with blood or hair.•Teeth can be a useful matrix for both acute and chronic assumptions of drugs.•The mechanism of adsorption in teeth is influenced by the method of assumption.
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