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Liang C.,Shanghai Institute of Forensic Science | Ye H.,Shanghai Institute of Forensic Science | Wang R.,Shanghai Institute of Forensic Science | Ni C.,Shanghai Institute of Forensic Science | And 2 more authors.
Journal of Separation Science | Year: 2015

A liquid chromatography with tandem mass spectrometry method was developed for the simultaneous screening of 34 drugs and poisons in forensic cases. Blood (0.5 mL, diluted 1:1 with water) or 1.0 mL of urine was purified by solid-phase extraction. Gastric contents (diluted 1:1 with water) were treated with acetonitrile, centrifuged, and supernatant injected. Detection was achieved using a Waters Alliance 2695/Quattro Premier XE liquid chromatography tandem mass spectrometry system equipped with electrospray ionization, operated in the multiple reaction monitoring modes. The method was validated for accuracy, precision, linearity, and recovery. The absolute recovery of drugs and toxic compounds in blood was greater than 51% with the limit of detection in the range of 0.02-20 ng/mL. The absolute recovery of drugs and toxic compounds in urine was greater than 61% with limit of detection in the range of 0.01-10 ng/mL. The matrix effect of drugs and toxic compounds in urine was 65-117% and 67-121% in blood. The limit of detection of drugs and toxic compounds in gastric content samples were in the range of 0.05-20 ng/mL. This method was applied to the routine analysis of drugs and toxic compounds in postmortem blood, urine, and gastric content samples. The method was applied to actual forensic cases with examples given. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Wang R.,Shanghai Institute of Forensic Science | Wang X.,Shanghai Institute of Forensic Science | Wang X.,Shanghai Institute of Pharmaceutical Industry | Liang C.,Shanghai Institute of Forensic Science | And 5 more authors.
Forensic Science International | Year: 2013

A μElution solid-phase extraction (SPE) liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for simultaneous determination of diazepam, nordiazepam, oxazepam, oxazepam glucuronide, temazepam and temazepam glucuronide in human whole blood is presented. 200. μL of whole blood samples were loaded onto a Waters Oasis HLB 96-well μElution SPE plate using 75. μL of methanol as the elution solvent, and the eluents were injected into an Eclipse XDB C18 column. No hydrolysis, solvent transfer, evaporation or reconstitution was involved in the sample preparation procedures. Tandem mass spectrometric detection with Turbo Ion Spray was conducted via multiple reaction monitoring (MRM) under positive ionization mode. The method was validated and proved to be accurate (accuracy within 93-108%), precise (intra-day RSD. <. 9.9% and inter-day RSD. <. 7.2%) and sensitive with limits of detection (LOD) in the range of 0.05-0.25. ng/mL for all the compounds. Extraction recoveries were in the range of 31-80% for all the analytes. This method demonstrated to be reproducible and reliable. The applicability of the method was demonstrated by analysis of several forensic cases involving diazepam and its metabolites. © 2013. Source


Wang X.,Shanghai Institute of Pharmaceutical Industry | Wang X.,Shanghai Institute of Forensic Science | Wang R.,Shanghai Institute of Forensic Science | Zhang Y.,Shanghai Institute of Forensic Science | And 4 more authors.
Journal of Chromatography A | Year: 2012

A method for the simultaneous direct analysis of diazepam oxazepam glucuronide, temazepam glucuronide, oxazepam, nordiazepam, and temazepam in human urine was developed and validated. Urine sample was purified by solid phase extraction (SPE), and the analysis was achieved using a liquid chromatography-tandem mass spectrometry (LC-MS/MS) system equipped with an electrospray ionization source (ESI). Multiple reaction monitoring (MRM) mode was used to analyze the target compounds. Extraction recoveries were 65-122% for all the analytes. The method showed acceptable intra-assay and inter-assay precision (both relative standard deviation (RSD) ≤ 11.2%) for quality control (QC) samples. The limits of detections (LODs) were in the range of 0.1-2. ng/mL. The present assay was applied to analyze the urine obtained from three volunteers after oral administration of a single dose 5. mg of diazepam. The results showed that, the detection periods of oxazepam glucuronide and temazepam glucuronide were much longer than diazepam and other metabolites. © 2012 Elsevier B.V. Source


Xiong L.,Shanghai Institute of Pharmaceutical Industry | Xiong L.,Shanghai Institute of Forensic Science | Wang R.,Shanghai Institute of Forensic Science | Liang C.,Shanghai Institute of Forensic Science | And 7 more authors.
Analytical and Bioanalytical Chemistry | Year: 2013

Ecgonine is suggested to be a promising marker of cocaine (COC) ingestion. A combined mass spectrometry (MS) and tandem MS (MS/MS) method was developed to simultaneously determine ecgonine and seven other metabolites of cocaine in human urine and whole blood with ultra-high-pressure liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. The compounds were extracted from as little as 100 μL of sample by solid-phase extraction with a 96-well μElution solid-phase extraction plate. The protonated molecules or fragment ions at accurate mass acquired in MS mode were used to quantify specific analytes, following by dedicated MS/MS identification. The assay was linear in the range from 5 to 50-100 ng/mL for urine samples, except for ecgonine methyl ester (10-200 ng/mL) and ecgonine (40-400 ng/mL), and was linear from 1-2 to 50 ng/mL for whole blood samples, except for ecgonine methyl ester (20-1,000 ng/mL) and ecgonine (40-2,000 ng/mL). The correlation coefficients were all greater than 0.99. The limits of detection ranged from 0.2 to 16 ng/mL, and the lower limits of quantification ranged from 1 to 40 ng/mL. The repeatability and intermediate precision were 18.1 % or less. The accuracy was in the range from 80.0 to 122.9 %, process efficiencies were in the range from 8.6 to 177.4 %, matrix effects were in the range from 28.7 to 171.0 %, and extraction recoveries were in the range from 41.0 to 114.3 %, except for ecgonine (12.8 % and 9.3 % at low and high concentrations, respectively). This method was highly sensitive in comparison with previously published methods. The validated method was successfully applied to the analysis of real samples derived from forensic cases, and the results verified that, on the basis of data from four positive samples, ecgonine is a promising marker of cocaine ingestion. [Figure not available: see fulltext.] © 2013 Springer-Verlag Berlin Heidelberg. Source


Xiong Z.,East China University of Science and Technology | Zhang L.,East China University of Science and Technology | Zhang R.,Shanghai Institute of Forensic Science | Zhang Y.,Shanghai Institute of Forensic Science | And 2 more authors.
Journal of Separation Science | Year: 2012

A simple and effective preconcentration method based on magnetic core-shell silica nanoparticles with C18-modified surface was developed for the analysis of pesticide residues in environmental water samples by gas chromatography-mass spectrometry. Several kinds of organophosphorous and pyrethroid pesticides including methamidophos, dichlorvos, orthene, phorate, dimethoate, carbofuran, bifenthrin, fenpropathrin, cypermethrin, fenvalerate, and deltamethrin were used as model compounds to systematically evaluate the method. Various parameters, including the amounts of magnetic nanoparticles absorbents, extraction time, eluting solvent, eluting volume, and sample pH values were optimized. The optimized method affords low detection limits (signal-to-noise ratio = 3) from 0.001 to 0.008 μg/L, and shows good linearity with correlation coefficients over 0.9990 in the concentration range of 0.025-0.5 μg/L. Average recoveries at three spiked levels were in the range of 70.2-110.2% with relative standard deviations below 9.6%. A maximum enrichment factor of 1015 times was achieved. Analysis results of poisoned pond water indicate that this method is fast, convenient, and efficient for the detections of low-concentration pesticides in aqueous samples. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

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