Analysis of Hair for Cocaine (From Hair Testing for Drugs of Abuse: International Research on Standards and Technology, P 91- 120, 1995, Edward J. Cone, Michael J. Welch, and M. Beth Grigson Babecki, eds. -- See NCJ-176397)

• NCJ Number: 176399
• Author(s): R T Jones; R T Jones; R T Jones
• Date Published: 1995
• Length: 30 pages
• Grant Number(s): RO1-DA082228
• Sponsoring Agency: National Institute on Drug Abuse
• Sale Source: National Institute on Drug Abuse; NCJRS Photocopy Services
• Language: English
• Country: United States of America

Annotation

There are several sensitive methods now available for the analysis of cocaine and metabolites in hair; however, until the testing technology is standardized, the mechanisms of cocaine incorporation into hair are better understood, and unequivocal procedures for distinguishing between drug ingestion and external contamination are developed, the results from hair tests for cocaine should be interpreted with caution.

Abstract

The findings from relevant research to date suggest that cocaine and benzoylecgonine (and probably other drugs) may be readily incorporated into hair from environmental exposure and not removed by any one of several decontamination techniques. The procedures outlined in this paper using radiotracers allow many specimens to be analyzed under a variety of conditions with high precision. Any new decontamination procedure could be tested through the use of these techniques. Metabolites of drugs in hair may distinguish active use from passive exposure; however, for cocaine, most of the metabolites may be produced by means other than drug ingestion. Several variables other than the decontamination procedure must be considered in the analysis of hair. The most important is the method by which drugs are to be extracted from the hair matrix. Based on the discussion in this paper, dissolution of the hair matrix before extraction of the drug appears to be necessary to achieve complete removal. The evidence from the authors' laboratory and from others reviewed in this study reinforces and extends the serious concern that external contamination of hair by drugs of abuse can easily occur. Thus, any interpretation of hair analysis data should be tempered by the prospect that the sample could have been externally contaminated. Substantial additional information is needed on the mechanisms for incorporation of drugs into hair, the decontamination of hair, the differentiation between exposure to exogenous and endogenous drugs, and the meaning of the presence of metabolites in hair before hair analysis can be used in many forensic applications. 76 references, 25 figures, and 5 tables