INFLUENCE OF CHEMICAL STRAIGHTENING ON THE STABILITY OF DRUGS OF ABUSE IN HAIR

 

Jeanita S. Pritchett and Karen W. Phinney

 

                Hair analysis has become a popular method used in forensic and workplace settings to determine a subject’s illicit drug use. While it tends to be complementary to urine or blood analysis, it also offers the advantage of a longer detection window and can be used to distinguish between intermittent and chronic usage.  However, factors such as cosmetic treatments can alter the measured content thus leading to false negative or false positive results.  Chemical straightening, more commonly known as a relaxer, is ubiquitously used amongst African American women to obtain straighter hair compared to their natural tresses.  This poster demonstrates 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 Elements™) were applied in vitro to drug fortified hair (SRM 2379 and 2380) and hairs clipped from authenic drug users.    Target analytes (cocaine, benzoylecogonine, cocaethylene, phencyclidine, and tetrahydrocannabinol) were isolated using solid-phase extraction then analyzed with isotope dilution gas chromatography mass spectrometry with selective ion monitoring. After either treatment, drug concentrations were significantly (P<0.05) reduced in both the SRM sample and the hair from authentic abusers.  In the SRM groups, 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 cocaine, benzoylecoginine, and cocaethylene.