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Influence of Chemical Straightening on the Stability of Drugs of Abuse in Hair



Jeanita Pritchett, Karen W. Phinney


Chemical straightening, also known as a relaxer, is ubiquitously used among African American women to obtain straighter hair compared with their natural tresses. This study focused on the stability of drugs of abuse in hair after a single application of the relaxer. Commercially available ‘Lye' or ‘No-Lye' chemical straightening products (Silk ElementsTM) were applied in vitro to drug-fortified hair (standard reference materials (SRM) 2379 and 2380) and hairs clipped from established drug users. Target analytes (cocaine (COC), benzoylecgonine (BZE), cocaethylene (CE), phencyclidine and tetrahydrocannabinol) were isolated using solid-phase extraction and then analyzed with isotope dilution gas chromatography-mass spectrometry with selective ion monitoring. After either treatment, drug concentrations were significantly (P < 0.05) decreased in both the SRM sample and the hair from authentic abusers. In the SRMgroups, 6-67% of the original concentration remained after a single chemical treatment. Similarly, only 5-30%of the original concentration remained in authentic drug hairs that had formerly tested positive for COC, BZE and CE.
Journal of Analytical Toxicology


Hair Analysis, Illicit Drugs, ID-GC/MS, cosmetic treatment, Drug Stability


Pritchett, J. and Phinney, K. (2014), Influence of Chemical Straightening on the Stability of Drugs of Abuse in Hair, Journal of Analytical Toxicology, [online], (Accessed June 21, 2024)


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Created October 7, 2014, Updated November 10, 2018