Hair analysis by GC/MS/MS to verify abuse of drugs.

Because of its peculiar characteristics, hair analysis provides a way of obtaining information that cannot be acquired by other commonly used forensic medical analyses, such as blood or urine analysis. In the keratin matrix many xenobiotics are incorporated permanently, in contrast to the situation with blood or urine where they are generally only detectable for a few hours or days. Therefore hair analysis should be the method of choice in the clinical and forensic toxicology field when the assessment of repeated or chronic exposure to a drug is required, e.g. in the case of criminal responsibility, revocation/restoration of a driving licence or in workplace testing. Some factors that can affect the concentrations of drugs in hair, such as passive contamination, age, ethnicity and cosmetic treatment, must be considered. Analytical methodology is also very important: GC/MS/MS has proved to be a highly sensitive and specific technique for the detection of very low concentrations of such drugs in hair. In this study five cases of the application of hair analyses using this technique for the determination of abused drugs (opiates, cocaine, amphetamine, anabolic steroids) are described.