Evaluation of acetylcodeine as a specific marker of illicit heroin in human hair

In addition to acetylmorphine (6-AM), acetylcodeine (AC) has been suggested as a marker for the use of illicit heroin. Because no procedure was available for AC testing in hair, a new method was developed for the simultaneous identification and quantitation of morphine (MOR), codeine (COD), 6-AM, and AC. After decontamination, each hair specimen was cut into 1-mm pieces. A 50-mg aliquot was incubated overnight at 50°C in 1 mL Soerensen buffer (pH 7.6) in presence of 200 ng of MOR-d3, COD-d3, 6-AM- d3, and AC-d3. After pH adjustment to 8.4, the analytes were extracted in 5 mL of chloroform/isopropanol/n-heptane (25:10:65, v/v/v). The organic phase was removed and evaporated to dryness, and the residue was derivatized by silylation (BSTFA + 1 % TMCS). Drugs were analyzed by gas chromatography- mass spectrometry in electron impact mode. Limits of quantitation were set to 0.1 ng/mg. Fifty hair specimens obtained from subjects who died from fatal opiate overdose were analyzed. AC was detected in 22 samples in concentrations ranging from 0.17 to 5.60 ng/mg with a mean value of 1.04 ng/mg. 6-AM was also present in these samples at concentrations ranging from 1.35 to 41.10 ng/mg with a mean value of 7.79 ng/mg. Of the 28 specimens negative for AC, 21 were positive for 6-AM at concentrations ranging from 0.18 to 7.13 ng/mg. When detected, the AC concentrations were an average of 15.5% (2.8 to 32.6%) of the 6-AM concentrations. There was a positive relationship between AC concentrations and 6-AM concentrations (r = 0.915, p = 0.001). Neither AC nor COD was identified in hair specimens collected from 20 subjects taking part in a heroin-maintenance program in Switzerland and receiving pure pharmaceutical heroin hydrochloride daily. Although it is indicative of illicit heroin use, AC would not make a suitable biomarker in place of 6-AM because of its low concentration in hair compared with that of 6-AM and its absence in about 50% of the specimens that tested positive for 6-AM.