Determination of ethyl-glucuronide in hair for heavy drinking detection using liquid chromatography-tandem mass spectrometry following solid-phase extraction.

The detection of ethyl-beta-D-6-glucuronide (EtG), a stable phase II metabolite of ethanol, is of interest in both clinical and forensic contexts with the aim of monitoring alcohol abuse. We present a liquid chromatography-electrospray ionisation-tandem mass spectrometry method for the detection and quantification of EtG in hair. Thirty milligrams of washed and cut hair were cleaned up using solid-phase extraction graphite cartridges. Separation was then performed using an Uptisphere-3SI column, and the detection was operated in the negative mode. After validation, the method was applied to hair samples taken from four fatalities (F) with documented excessive drinking habits, 12 heavy drinkers (HD) and seven social drinkers (SD). The method exhibits limits of detection and quantification of 4 and 10 pg/mg, respectively. Intra- and inter-assay standard deviation and relative bias were less than 20% over the calibrating range (10 to 3,000 pg/mg). EtG hair concentrations in SD were <10 pg/mg and >50 pg/mg for F and HD (range, 54 to 497 pg/mg). The present assay appears convenient to carry out owing to the very small quantity of hair samples required to determine an effective heavy alcohol consumption (EtG hair concentration >50 pg/mg).

A fatal case of bupropion (Zyban) overdose.

A sensitive and reproducible method for the identification and the quantitative determination of bupropion (BUP) and its major metabolites, hydroxybupropion (OH-BUP) and threohydrobupropion (T-BUP), was developed in blood and urine. The three compounds were extracted with a solid-phase extraction procedure followed by LC-ESI-MS-MS separation and quantification using decadeuterated lidocaine as internal standard. BUP and its metabolites were satisfactorily identified by multiple reactions monitoring detection. The limits of detection and quantification were determined at 5 and 10 microg/L, respectively, for each analyte. The intraday and interday coefficients of variability were lower than 11.9% for BUP and its metabolites. This method was applied to the forensic case of a 35-year-old male who died after a suspected ingestion of 30 slow-release tablets of Zyban. As samplings were performed at least 72 h after the drug intake, BUP had disappeared from blood, but OH-BUP and T-BUP were present at the concentrations of 5.8 and 30.4 mg/L, respectively. In urine, concentrations ranged from 42.9 mg/L for BUP to 617 mg/L for T-BUP. These results agree with the hypothesis of a successful suicide attempt.

Ultra-performance liquid chromatography- tandem mass spectrometry method for the determination of bupropion and its main metabolites in human whole blood.

A selective and sensitive ultra-performance liquid chromatography (UPLC)-electrospray ionization-tandem mass spectrometry (MS) method for simultaneous determination of bupropion and its main metabolites, hydroxybupropion, erythrohydrobupropion, and threohydrobupropion, in human whole blood is presented. The sample preparation consists of cleanup protein precipitation with methanol combined with a solid-phase extraction on Oasis HLB cartridges. Analytes were separated on a Waters Acquity UPLC((R)) BEH phenyl column using a binary mobile phase consisting of ammonium formate buffer (2 mM, pH 4) and acetonitrile. Detection was performed on a Waters Acquity UPLC system coupled to a Quattro Premier triple-quadrupole MS in positive ion selected reaction monitoring. Internal standards were bupropion-d(9) and hydroxybupropion-d(6). Linearity was from 5 to 1000 ng/mL for bupropion and from 10 to 2000 ng/mL for metabolites. Accuracy profiles (80-120%), precision (< 15%), and limits of detection (1 ng/mL for bupropion and 2 ng/mL for metabolites) were also evaluated and responded to all criteria of validation. The aim of this study was to compare this presented method with a previously described method developed on a classic liquid chromatography-tandem MS system.