Publications by authors named "Duoqi Xu"

A novel synthetic cannabinoid receptor agonist (SCRA), ADMB-FUBIATA, featuring an acetamide-linked structure, has emerged on the illicit drug market. To provide dependable verification of its consumption and identify reliable biomarkers, we investigated an in vitro metabolism study of ADMB-FUBIATA incubated with human primary hepatocytes (HPHs) for the first time and correlated our findings with those from human liver microsomes (HLMs). In this work, ADMB-FUBIATA (10 μM) was incubated with HLM and HPH for 1 and 5 h, respectively, and then subjected to LC-quadrupole-orbitrap MS.

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Estimation of drug ingestion time (event time) and distinguishing between drug ingestion and external contamination are important for interpreting hair analysis results in forensics practice. Here, we present a matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI) method for in situ analysis of intact hair. We applied a longitudinal cutting method for a single hair to analysis authentic hair samples from a victim of a drug-facilitated sexual assault (DFSA) case and zolpidem-soaked hair.

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Article Synopsis
  • The study analyzed etizolam, a commonly abused designer benzodiazepine, using UPLC-Q-Exactive-MS for a detailed look at its metabolism and pharmacokinetics in rats.
  • A new pharmacokinetic model based on Lorentz function was developed, improving the accuracy of drug detection and providing insights into etizolam's popularity in the new psychoactive substances market.
  • The research identified 21 metabolites, four of which are long-acting, enhancing detection capabilities and offering valuable information for forensic experts and drug policy development.
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Objectives: To establish an LC-MS/MS method based on single hair micro-segmental technique, and verify the detection of 42 psychoactive substances in 0.4 mm hair segments.

Methods: Each piece of single hair was cut into 0.

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Hair testing is well established for the assessment of past drug exposure; however, more research is needed to understand drug incorporation mechanisms and drug entry pathways into hair. In this study, a micro-segmental LC-MS/MS method was used to analyze a 0.4 mm segment of hair after a single oral administration of zolpidem.

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In recent years, an increasing number of new synthetic cannabinoids (SCs) have appeared in the drug trade market. A UPLC-MS/MS method was developed to simultaneously identify five synthetic cannabinoids in 1 cm segment hair samples. The method was fully validated and confirmed to have good selectivity, accuracy, and precision, as well as satisfactory linearity within the calibrated range.

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Purpose: In this study, an analytical procedure to identify trace amounts of drug in hair based on micro-segmental hair analysis was presented. The method also can be used to estimate the time of drug ingestion at daily precision by cutting a single hair into sub-millimeter segments which correspond to daily hair growth.

Methods: A method was established for efficient extraction of midazolam, one of the most frequently detected compound in drug-facilitated sexual assault (DFSA) cases, from each 0.

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The mechanism of estazolam incorporation into hair was investigated by studying the time course of estazolam along single-strand hair after two oral administration of estazolam at 28 days interval. Estazolam in single hair segments 0.4 mm in length was verified and quantified by ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS).

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The emergence of novel drugs and the continuous expansion of the scope of the types of drugs under control have greatly increased requests for screening of a range of drugs in hair. Here, a multi-analyte method for the detection and quantification of 88 psychotropic drugs in the hair of addicts in drug abstinence was developed and fully validated using liquid chromatography-tandem mass spectrometry (LC-MS-MS). Hair samples (25 mg) were washed, cut into pieces, cryogenically ground and extracted in methanol.

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In this study, in vivo metabolic studies of the synthetic cannabinoid 4F-MDMB-BICA were investigated using zebrafish models. The metabolites were identified and structurally illustrated by liquid chromatography-high resolution mass spectrometry. Fourteen phase-I metabolites and four phase-II metabolites were generated from zebrafish.

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MDMB-CHMINACA is a newly synthetic cannabinoid, which scoped in NMS Lab, USA. Since there are currently no published data on MDMB-CHMINACA metabolism, we aimed to identify its biotransformation pathways and major metabolites. Liquid chromatography Q-exactive HF hybrid quadrupole-orbitrap mass spectrometry (LC-QE-HF-MS) using full scan positive ion mode and targeted MS-MS (ddms2) techniques with accurate mass measurement were employed to analyze the metabolic sites and pathways.

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Flunitrazepam (FNZ) is a potent hypnotic, sedative, and amnestic drug used to treat severe insomnia. In our recent study, FNZ metabolic profiles were investigated carefully. Six authentic human urine samples were purified using solid phase extraction (SPE) without enzymatic hydrolysis, and urine extracts were then analyzed by liquid chromatography-Q exactive-HF hybrid quadrupole-Orbitrap-mass spectrometry (LC-QE-HF-MS), using the full scan positive ion mode and targeted MS/MS (ddms2) technique to make accurate mass measurements.

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In this study, the metabolic profiles of a new illicit drug AMB-FUBINACA were investigated using both human liver microsome and zebrafish models. Liquid chromatography Q Extractive HF Hybrid Quadrupole-Orbitrap mass spectrometry (LC-QE-HF-MS) was employed to analyze the metabolic sites and pathways. AMB-FUBINACA was added to the liver microsome incubation model to simulate the metabolic processes in human body.

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