Hair analysis: A powerful tool for the screening of drugs of abuse

Nowadays, the analysis of drugs of abuse in hair has become more and more important in most laboratories dealing with forensic toxicological analysis. In fact, hair analysis is considered to be complementary to urine analysis. In our laboratory, such analyses were first performed in 1995. Since then requests for hair analysis have increased and have become routine. A method was developed to analyze most drugs of abuse. This method consists of four important steps: Sample preparation, hydrolysis, automatic solid-phase extraction and gas chromatography-mass spectrometry analysis. Particular care has to be taken during sample preparation and in the interpretation of the analytical results. Two other methods were developed, one to confirm consumption of cocaine by the identification of metabolites and to avoid the risk of false-positive results and another to follow subjects under medical heroin treatment.