The detection of acetylcodeine and 6-acetylmorphine in opiate positive urines

Acetylcodeine (AC), an impurity of illicit heroin synthesis, was investigated as a urinary biomarker for detection of illicit heroin use. One hundred criminal justice urine specimens that had been confirmed positive by GC/MS for morphine at concentrations > 5000 ng/ml were analyzed for AC, 6-acetylmorphine (6AM), codeine, norcodeine and morphine. The GC/MS analysis was performed by solid phase extraction and derivatization with propionic anhydride. Total codeine and morphine concentrations were determined by acid hydrolysis and liquid/liquid extraction. AC was detected in 37 samples at concentrations ranging from 2 to 290 ng/ml (median, 11 ng/ml). 6AM was also present in these samples at concentrations ranging from 49 to 12 600 ng/ml (median, 740 ng/ml). Of the 63 specimens negative for AC, 36 were positive for 6AM at concentrations ranging from 12 to 4600 ng/ml (median, 124 ng/ml). When detected, the AC concentrations were an average of 2.2% (0.25 to 10.2%) of the 6AM concentrations. There was a positive relationship between AC concentrations and 6AM concentrations (r = 0.878). Due to its very low concentration in urine, AC was found to be a much less reliable biomarker for illicit heroin use than 6AM in workplace or criminal justice urine screening programs. However, AC detection could play an important role in determining if addicts in heroin maintenance programs are supplementing their supervised diacetylmorphine doses with illicit heroin.