ABSTRACT

Chemicals in the bloodstream, including both licit and illicit drugs and their metabolites, diffuse from the circulatory system to the rapidly growing hair follicle, with subsequent encapsulation within the keratin fibers. The greatest challenge in the area of hair analysis has been the development of ultrasensitive Mass Spectrometry technologies to provide reliable confirmation of structure. The analysis of trace levels of drugs of abuse in hair has rapidly become the preferred method by many corporations to provide data on drug use of preemployment candidates stretching over the past 90 days rather than the 3 to 4 day time window provided by urine analysis. G. L. Henderson has suggested that there may be a more complex mechanism of drug incorporation into growing hair. Hair sampling possesses several unique advantages over traditional urine sampling. The cortex is the most predominant structural element of hair and primarily consists of tightly packed macrofibrils containing keratin.