This research evaluated the effects of cocaine (COC) composition, COC incorporation by ingestion and external contamination, and hair color (light and dark hair) on COC analytes and analyte-to-parent ratios found in hair.
The research concluded that the use of cut-off concentrations for any or all of the COC analytes would not be sufficiently reliable to discriminate a COC user’s hair from a nonuser’s hair contaminated with COC from the environment. The use of analyte ratios provides more information and some ability to discriminate user specimens from contaminated specimens; however, the use of cocaethylene (CE) and norcocaine (NCOC) concentrations and ratios does not discriminate any more efficiently than decision criteria using only benzoylecgonine (BE) and COC. All three analytes (CE, NCOC, and BE) can be present in varied concentrations in illicit COC as byproducts of the manufacturing process, which will confound the use of ratios in discriminating contaminated hair from user hair. Even after decontaminating the hair, the application of concentration and ratio decision points did not adequately discriminate contamination from drug use. These results have implications for the proposed Federal Mandatory Guidelines for laboratory testing, because the decision criteria as proposed in this study do not adequately discriminate contamination. This is of particular concern for individuals whose occupation (e.g., law enforcement) may put them in contact with large amounts of COC in their environment, which can then be transferred to samples of tested hair. A requirement for decontamination and further research are needed in order to determine the viability of comparative criteria using information from the decontamination. The study methodology involved the evaluation of COC and COC analyte concentrations and ratios in user hair from various populations, hair contaminated with various sources of COC, and an alternate external application of COC to hair (fortification). 18 figures, 31 tables, 62 references, a listing of publication and presentation on the findings, and appended detailed data on user population and contaminated hair