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Bone marrow (BM) analysis is of forensic interest for postmortem toxicological investigations where blood samples are unavailable or unusable. Due to the lack of studies, it remains difficult to interpret concentrations of xenobiotics measured in this matrix. Based on a statistical approach published previously to interpret meprobamate concentrations in bile and vitreous humor, we propose here a diagnostic test for interpretation of BM meprobamate concentrations from analysis of 99 sets of autopsy data. The mean age was 48 years (range 18-80 years, one unknown) for males and 50 years (range 19-80 years, one unknown) for females, with a male/female ratio at 0.768. A BM concentration threshold of 11.3 μg/g was found to be statistically equivalent to that of a blood meprobamate concentration threshold of 50 μg/ml in distinguishing overdose from therapeutic use. The intrinsic qualities of this diagnostic test were good with sensitivity of 0.82 and specificity of 0.92. Compared to previous tests published with the same objective on vitreous humor and bile, this study shows that BM is a useful alternative matrix to reveal meprobamate overdose when blood, vitreous humor, and bile are not available or unusable.

We describe a simple method for the urinary identification and blood quantitation of meprobamate suitable for any toxicological laboratory. After urinary screening using GC-MS technology, quantitation is performed by GC-MS in the selected-ion monitoring mode. Isolation of the drug is achieved by solid phase extraction on a C-18 cartridge. A specific elution is obtained by three volumes of acetone:triethylamine (99:1 v/v). Lidocaine is used as internal standard. RSDs (%) of the within-day and between-day precision studies are always less than 7.2 on the entire range of calibration. Linearity is inspected using an analysis of variance ANOVA. Homogeneity of the variances is tested using Hartley's test. Weighted linear regression is then computed. Limits of detection and quantification are given by an analysis of the blanks. The present method was applied in our laboratory over a period of 1 year. Meprobamate appeared as a drug which still has a significant frequency (5.5%) and is the most frequently involved in fatal pharmaceutical overdoses (15.3%). Post mortem concentrations ranged from 41 to 397 mg/l (mean = 182) and are compared to those of the literature.

This gas chromatographic technique of determining meprobamate is based on a solid-phase extraction permitting a time reduction of the analysis and improving sensitivity. Quantification is realized on 500 microliters of plasma. The method uses etidocaine as internal standard and does not require derivatization. Thus it is simple, rapid, sensitive and applicable in forensic and clinical toxicological laboratories.