Hair analysis for drugs of abuse

Abstract

The reliable analytical method for total morphine in hair was established by GC/MS-SIM. The calibration curve for morphine in hair showed linear over 0.5–100 ng/mg hair. Though the limit of detection was 0.1 ng/mg hair with an S/N >3 of the base ion(m/z 429) for morphine, the limit of confirmation by detection of three major ions was 0.5 ng/mg. The hydrolytic extraction of the morphine analogs in hair with 10% HCl for 1 h at 100° C gave quantitative recovery of morphine. The reproducibility of recovery of morphine spiked to the control hair was 2.9–7.3% in a concentration range between 2 and 50 ng/mg hair. The three monkeys were administered once a day with morphine at 10 mg/kg and heroin at 2.5 mg/kg, respectively, for 10 days and their back hair newly grown for 10 weeks was cut for analysis. The levels of total morphine in monkey hair intoxicated with morphine and heroin were 3.4 and 5.2 ng/mg, respectively. Taking their doses into account, it is concluded that the morphine level in hair from monkeys administered with heroin was 6 times higher than that with morphine. In hair from monkeys and humans intoxicated with heroin, 6-acetylmorphine was detected at the level of 0.7–7.2 ng/mg as a major component in hair together with morphine and no heroin. Drug concentrations of sectional hair shaft cut 2 cm each from the root side were compared with the self-reported drug histories of three cases. The results of sectional analysis of heroin abuser's hair suggested that the relationship between the distribution of morphine along hair shaft and the drug use history showed a good correlation, though the accumulation of heroin metabolites in body could result from chronic use of heroin.