Hydroxycocaines as Metabolic Indicators of Cocaine Ingestion.

Hydroxycocaines in hair were investigated with many hundreds of head and body hair samples. All samples were washed by a published extensive aqueous method prior to confirmation by LC-MS/MS. Concentrations, percent of cocaine, and ratios of para- and meta-hydroxycocaines to ortho-hydroxycocaine are presented. Hydroxycocaines as percent of cocaine did not appear to be affected by cocaine concentrations, but were shown to increase with cocaethylene concentrations. Stability of hydroxycocaines over a year of ambient storage was demonstrated. Ortho-hydroxycocaine was shown to be formed by exposure of cocaine-positive hair to peroxide, while para- and meta-hydroxycocaines were not. Presence of para- or meta-hydroxycocaine at > 0.05% of cocaine is proposed as indicating ingestion of cocaine. This indicator prevents black hair from being more likely interpreted as positive for ingestion than lighter colored hair.