Issn Print: 1076-2752
Publication Date: 1997/04/01
Workplace Drug Testing by the Analysis of Hair
Excerpt
Hair analysis for drugs of abuse by immunoassay screening and gas chromatography/mass spectrometry confirmation provides retrospective information on an individual's drug use. The surveillance window for workplace drug testing is typically the most recent 90 days (4 cm of hair growth). Evasion by temporary abstention is therefore not possible; consequently pre-employment hair testing has identified up to seven times more drug users than urinalysis. Hair analysis is also more effective than urinalysis at differentiating between passive drug exposure and active drug use. Evidentiary false positives due to internal passive exposure are prevented by the use of more effective cut-off levels than those used by urinalysis. This is made possible by the constancy of drug levels in hair. Evidentiary false positives due to external contamination are avoided by: 1) application of highly effective wash procedures; and 2) measurement of metabolites. The heroin metabolite MAM (6-monoacetylmorphine) is trapped efficiently by hair; thus hair does not suffer from the problems of urinalysis where 95% of opiate-positive results are overturned because of the absence of MAM.
Facebook
Twitter
LinkedIn
Email
