Analysis of Drugs of Abuse in Human Hair: Surface Contamination and Localization of Analysis
Authors: Megan Grabenauer, Nichole D. Bynum, Katherine N. Moore
For more than two decades, researchers and scientists have utilized hair testing for drug abuse in addition to blood and urine tests.
Despite considerable research and current analytical technologies and interpretive methods, environmental contamination remains an unresolved issue for hair, and controversy exists over the source of drug residues found in hair and the potential for environmental contamination to cause false-positive test results.
The purpose of this study was to examine the effects of environmental contamination of human hair leading to external deposition of methamphetamine and heroin on drug tests designed to identify drug use.
The goals of this project were to determine:
1. The likelihood of whether methamphetamine and heroin can be adequately removed by an extended aqueous phosphate buffer decontamination procedure;
2. If, over time and with normal hygienic treatment of the hair, the drug will be removed from the hair or prove resistant to removal;
3. The extent to which normal hygienic treatment and the extended aqueous phosphate buffer decontamination procedure affect measurable levels of methamphetamine and heroin in hair from drug users who have ingested those compounds;
4. Whether several imaging techniques could be used to localize the site of incorporation of the drugs into hair as an indicator of the route of incorporation.
Prior studies have raised significant concerns about the potential for contamination to confound hair testing results, which could have direct consequences, either supporting or refuting claims of contamination being the source of positive hair results. The results from this study continue to raise such concerns.
Many hair testing laboratories have decontamination procedures prior to analysis in an attempt to remove and contribution from external contamination. This study shows that a decontamination step alone is likely not sufficient to remove contributions from external contamination.