Distribution of concentrations of cocaine and its metabolites in hair collected postmortem from cases with diverse causes/circumstances of death.

The concentrations and ratios of cocaine, benzoylecgonine (BE), and ecgoninemethylester (EME) in 360 head hair segments and 34 pubic hair samples collected at coroner's postmortem examinations were reviewed. The cases included diverse histories and causes/circumstances of death. The hair was analyzed using a validated method published previously; hair was shampoo washed, solvent washed, followed by extraction using 0.1 M hydrochloric acid and SPE clean-up, and quantitative analysis by gas chromatography-mass spectrometry in selected ion monitoring mode. A statistical evaluation demonstrated that, in head hair, the respective lower, middle, and upper concentration (ng/mg) ranges were < 10 ng total-0.8, > 0.8-18.9, and > 18.9-384.7 cocaine; < 10 ng total-0.6, > 0.6-7.9, and > 7.9-142.2 BE; and < 10 ng total-0.3, > 0.3-0.9, and > 0.9-39.5 EME. In pubic hair, the concentrations (ng/mg) detected were 0.2-236.2 cocaine, < 10 ng total-74.0 BE, and < 10 ng total-3.2 EME. The BE/cocaine ratio range in head hair was 0.01-43.00 (mean 1.39, median 0.28), and in pubic hair it was 0.31-2.67 (mean 0.59, median 0.31). The EME/cocaine ratio in head hair ranged from < 0.01 to 0.46 (mean 0.04, median 0.02), and in pubic hair, it ranged from < 0.01 to 0.32 (mean 0.07, median 0.04). Results reported as < 10 ng total were above the limit of detection and below the limit of quantitation (LOQ) (LOQ = 0.2 ng/mg for 50 mg of hair).