Identification of ozone-oxidation products of oxycodone by electrospray ion trap mass spectrometry

The products of oxycodone oxidized by ozone were characterized by electrosp ray ionization-tandem mass spectrometry (ESI-MS/MS). Liquid Chromatography( LC)-MS analyses revealed that the main constituents in the oxidation reacti on mixture included the protonated molecules m/z 316, corresponding to oxyc oclone, and m/z 332, m/z 348, m/z 366, corresponding to the oxidation produ cts. ESI-MS[MS and MSn spectra were used to study oxycodone fragmentation i n detail and to characterize the structures of oxidation products. The resu lts show that the oxidation products were formed by addition of one or two oxygen atoms or by addition of three oxygen and two hydrogen atoms to oxyco done. The fragmentation of the oxidation products also shows that the aroma tic ring oxidizes due to rupture of the C-3-C-4 bond during product formati on. Copyright (C) 2001 John Wiley & Sons, Ltd.