Validated assay for the determination of markers of illicit heroin in urine samples for the control of patients in a heroin prescription program

Abstract

A fully validated procedure for the simultaneous determination of morphine (MOR), morphine-3-glucuronide (M3G), morphine-6-glucuronide (M6G), 6-acetylmorphine (6AM), codeine (COD), codeine-6-glucuronide (C6G), acetylcodeine (AC), noscapine (NOS) and papaverine (PAP) based on liquid chromatography followed by electrospray mass spectrometry applying multiple reaction monitoring (LC-ESI-MS/MS) in urine samples is described. The extraction was carried out on a Zymark Rapid Trace Workstation using C18 solid-phase extraction cartridges. The separation was performed in 19 min on an Agilent 1100 HPLC system, using a Phenomenex C18 AQUA column (4 μm, 150 mm × 2 mm), which is coupled with an Applied Biosystems API 2000 mass spectrometer. Deuterated analogues were used as internal standards. The limits of detection were in the range of 0.1 ng/ml (PAP) to 7.4 ng/ml (M6G), the coefficients of correlation were higher than 0.996, the precisions ranged from 3% to 12% and the absolute recoveries were between 45% (M3G) and 98% (MOR). Analyses of samples from patients of a heroin prescription program demonstrated the usefulness of the procedure for the analytical differentiation between prescribed synthetic heroin (diamorphine) use and non-prescription heroin abuse on the basis of urine analysis. After the ingestion of pharmaceutical heroin only general markers for heroin use were detected, which are MOR, M3G, M6G and 6AM, respectively. When illicit heroin was abused, additionally to further general markers (COD, C6G) specific markers for non-prescription heroin abuse (AC, NOS, PAP) were found. However, it must be kept in mind that only AC may be regarded as absolute specific marker of non-prescription heroin, because all other compounds may appear in urine after ingestion of opiate alkaloids containing medicines or foods (e.g. poppy seeds). Therefore, patients of a heroin prescription program should be advised not to ingest such products.