Identification of cocaine-contaminated hair: Perspectives on a paper

John M. Mitchell; M Schaffer; V Hill; T Cairns; Peter Stout; JD Ropero-Miller; Michael Baylor; John M. Mitchell

Identification of cocaine-contaminated hair: Perspectives on a paper

Schaffer, M., Hill, V., Cairns, T., Stout, P., Ropero-Miller, JD., Baylor, M., & Mitchell, J. (2007). Identification of cocaine-contaminated hair: Perspectives on a paper. Journal of Analytical Toxicology, 31(3), 172-176. http://www.jatox.com/index.php/Articles/Letter-to-the-Editor-Identification-of-Cocaine-Contaminated-Hair-Perspectives-on-a-Paper.html

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Abstract

n the October 2006 issue of the Journal, Stout et al. (1) discuss results of an experiment by RTI International (RTI) and three commercial laboratories that analyzed hair contaminated with cocaine (COC). Equivalent sets of samples were 1. decontaminated by RTI, 2. decontaminated by the commercial labs, and 3. not decontaminated by any method. The original study design directed the labs to analyze only for COC and benzoylecgonine (BE) (2). As a participating laboratory, Psychemedics has verified that our lab identified correctly and reported to RTI the contaminated samples washed by our method as either negative or contaminated using cutoff, metabolite ratio, and wash criterion. Stout and colleagues also state that the use of our wash method (3) by the RTI laboratory correctly identified 65 of 65 contaminated samples as negative by cutoff, BE/COC ratios, or wash criterion, validating both our results and our reported experience in identifying environmental contamination using extended aqueous washing and a wash criterion (3).