A simple liquid chromatography-tandem mass spectrometry (LC-MS-MS) method has been developed and validated for simultaneous identification and quantification of γ-hydroxybutyrate (GHB), γ-butyrolactone (GBL), 1.4-butanediol (1.4-BD), and γ-valerolactone (GVL) in whole blood from forensic cases. The sample preparation of whole blood involved protein precipitation by acidic methanol. Urine samples were diluted and evaluated in relation to a control at the cutoff concentration. Hexadeutero GHB (GHB-d(6)) was used as the internal standard. Separation was achieved by reversed-phase chromatography, and detection was by MS-MS in MRM mode. The linear range for all compounds was from 1.0 to 100 mg/kg in whole blood with a limit of quantification of about 1 mg/kg. The method was validated with regards to selectivity, recovery, accuracy and precision, and stability. The method is currently applied to investigations on suspected drug-facilitated sexual assaults, driving under the influence of drugs, and general intoxication with these substances.
A fully automated solid-phase extraction (SPE) and ultra-performance liquid chromatography time-of-flight mass spectrometry (UPLC-TOF-MSE) method for screening of 30 acidic and neutral pharmaceuticals in whole blood was developed and validated.
The stability of γ-hydroxybutyrate (GHB) was determined in 50 blood samples from impaired drivers after storage at 4°C for up to 12 months. GHB was determined in whole blood by gas chromatography–flame ionization detector (GC–FID) after conversion into γ-butyrolactone (GBL) and results were compared with LC–MS-MS. Both analytical methods showed a linear response (R2 > 0.99) to GHB concentrations from 2 to 250 mg/kg. The mean decrease in concentration after storage was 4.8 mg/kg, with extreme changes of +13 mg/kg or −29 mg/kg. Results by the GC–FID–GBL method (y-variate) and the LC–MS-MS method (x-variate) were highly correlated (R2 = 0.974). The regression equation was y = 0.85x + 2.2 and residual standard deviation (SD) was 7.8 mg/kg. The y-intercept (2.2 mg/kg) was not significantly different from zero (P > 0.05), although the slope of the regression line (0.85) differed from unity (P < 0.001), indicating a proportional bias of 15%. The LC–MS-MS method tended to give higher results than the GC–FID–GBL method. The mean difference (bias) was 12 mg/kg (P < 0.001). The SD of individual differences was 11.3 mg/kg and 95% limits of agreement were −11 to +33 mg/kg. The results of this study show that concentrations of GHB in whole blood are stable during storage at 4°C for up to 6 months.
An isocratic reversed-phase high-performance liquid chromatography (HPLC) method is developed and validated for the quantitation of 3,4-methylenedioxymethamphetamine (MDMA) in tablets. The chromatographic separation is achieved with potassium phosphate buffer (pH 3.2)-acetonitrile (9:1, v/v) as mobile phase, a Chromspher B column, and UV detection at 210 nm. The calibration curve is linear from 1.4 to 111 µg/mL. The percent relative standard deviation for intra- and interday precision studies is 2.7% each. The measurement uncertainty is estimated to 9%. The method is specific and successfully used for routine quantitation of MDMA in tablets.
A LC/MS/MS application for identification and quantification of gamma-hydroxybutyrate (GHB), gamma-butyrolactone (GBL), 1.4-butanediol (1.4-BD) and gamma-valerolactone (GVL) in biological samples from forensic cases is developed. Sample preparation is a simple protein precipitation (whole blood) or dilution (urine). Chromatographic separation is achieved on a Zorbax SB C18 column and detection by a tandem mass spectrometer in MRM mode. The linear range in whole blood is from 0.5 mg/kg to 250 mg/kg for all compounds. The upper limit for the linear range in urine is 250 mg/L or 1000 mg/L depending on the compound. The accuracy is determined to ≥89 % and precision to ≤17 % for all analytes in both matrices. The method is applied in investigations on suspicion of drug rape and/or intoxication with these substances.
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