Cocaine contamination in pubic hair: Analysis of the decontamination method

Even if pubic hair represents a reliable and widely accepted alternative hair matrix to identify drug abusers, it might produce false positive results due to external contamination.The aim of this study was to verify whether the external contamination of pubic hair with cocaine could influence the discrimination between active users and false positive subjects. The analysis was performed on in vivo and in vitro samples; the contamination was carried out by rubbing pubic hair with cocaine hydrochloride contaminated hands for three consecutive days. Five days after the beginning of the contamination, the pubic hair was collected and analysed at different times for two months.Data from our studies show that all in vivo samples yielded false positives; the in vitro samples were negative only for 10 days and then yielded false positives.