Using Specific Metabolites Originated from Illicit Heroin Impurities to Confirm the Administration of Illicit Heroin in Urine

In the forensic toxicology, it is a challenge to confirm heroin administration, especially for those who are only be confirmed the presence of morphine but no detectable 6-acetylmorphine in their biological samples. However, illicit heroin, different from pharmaceutical heroin with high purity, is manufactured from the capsules of Papaver somniferum with a plenty of alkaloid impurities. Thebaine, one of the alkaloids, can be acetylated during the manufacturing process, and forming unusual rearrangement products, which have been thought to be specific features of illicit heroin. To apply these impurities as a marker in biological fluid to confirm heroin administration, we in vitro synthesized the phase I and phase II metabolites with human liver subfractions, and established a method using liquid chromatography-mass spectrometry. Urine samples from heroin abuser were analyzed to verify if the metabolites from acetylated thebaines can be detected. There were 12 metabolites identified by accurate masses and fragmentation patterns, and 8 of which have never been reported before. Besides, metabolite – ATM4S was detected in the real urine samples: 9 out of 14 samples presented with 6-acetylmorphine; 2 out of 7 samples only presented with morphine. Keywords: Liquid chromatography-tandem mass spectrometry; high resolution mass spectrometry; forensic toxicology; illicit heroin; metabolite identification; acetylated thebaines; alkaloids of Papaver somniferum; in vitro metabolism