Rapid quantification of urinary oxycodone and oxymorphone using fast gas chromatography-mass spectrometry.

Human urine specimens that were determined to be presumptively positive for oxycodone and its metabolite, oxymorphone, by immunoassay screening were assayed using fast gas chromatography-mass spectrometry to positively identify and quantify the oxycodone and oxymorphone present. Urine specimens were first spiked with deuterated internal standards, oxycodone-d(3) and oxymorphone-d(3), subjected to acid hydrolysis, and then extracted using a positive-pressure manifold and mixed-bed solid-phase cartridge extraction methodology. Extracts were derivatized using methoxylamine and acetic anhydride.