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One month before (T-1) and 12 months after (T12) controlled i.v. administration of pharmaceutical heroin-HCl (10-100 mg/day) in the context of a heroin maintenance program (HMP), concentrations of opiates and cocaine as well as its metabolites were determined in head hair (n = 46) using a validated gas chromatographic-mass spectrometric method. In addition, a patient collective of a methadone maintenance program (MMP, daily doses 15-260 mg) was examined (n = 35). The incidence of additional cocaine consumption decreased in both groups during the study period (T-1 to T12): in HMP from 64.6% to 45.8% and in MMP from 71.4% to 60.0%. A significant reduction of cocaine consumption was defined as an at least 30% reduction of analyte concentrations in hair (Deltac > 30%). Accordingly, in HMP, a decrease in 45.8% of initially (T-1) cocaine-positive patients was determined; in MMP, the reduction was 48.6%. In 22.9% of HMP and 37.1% of MMP, an increase of cocaine concentrations was detected. Codeine and acetylcodeine were found in 50.0% and 43.5% (T-1) and 13.0% and 10.9% (T12) of the samples of the HMP, as well as in 45.7% and 25.7% (T-1) and 17.1% and 5.7% (T12) in MMP, respectively. The missing of acetylcodeine, in particular at T-1, questions its applicability as a characteristic marker of a preceding consumption of illicit heroin in hair analysis.

The objective of this study was to develop a two-step strategy for analysis of opiates and cocaine in hair samples involving an immunological screening procedure followed by confirmation of results using gas chromatography-mass spectrometry (GC-MS). A semi-quantitative automated competitive enzyme-linked immunosorbent assay (ELISA) methodology using Oral Fluid Micro-Plate Enzyme Immunoassays (Orasure Technologies, Inc.) was developed and validated. Applicability was proven by analysis of authentic head hair samples from drug users (n=103) and from opiate associated fatalities (n=21). The optimum cutoff values for the ELISA tests were 0.1 ng cocaine-equivalents/mg hair and 0.05 ng morphine-equivalents/mg hair using a 50 mg hair sample. Both ELISA tests had a sensitivity of 100%, the specificity was 66% for cocaine-equivalents and 42% for morphine-equivalents. The intraassay precision was 11% for the cocaine and 3% for the opiates ELISA, while interassay precision was 12% for the cocaine and 4% for the opiates ELISA test. The actual analyte concentrations in the hair samples were determined using GC-MS and were between 0.04 and 5.20 ng/mg for heroin (HER), between 0.04 and 30.01 ng/mg for 6-monoacetylmorphine (MAM), between 0.03 and 11.87 ng/mg for morphine (MOR), between 0.02 and 1.84 ng/mg for codeine (COD), between 0.02 and 2.48 ng/mg for acetylcodeine (AC), between 0.01 and 21.37 ng/mg for cocaine (COC), between 0.03 and 10.51 ng/mg for benzoylecgonine (BE) and between 0.05 and 1.26 ng/mg for cocaethylene (CE). The automated ELISA tests were proven to be valid screening procedures for the detection of cocaine and opiates in hair as confirmed by GC-MS. Screening methods provide rapid and inexpensive automated pre-test procedures to detect drugs in hair or other matrices. For forensic purposes screening therefore represents an ideal complement to routinely applied GC-MS procedures.