Determination of Oxycodone and a Major Metabolite in Urine by Electron-Capture GLC

Abstract

An electron-capture gas chromatographic procedure has been developed for the analysis of oxycodone in human urine, using naloxone as internal standard. A major metabolite, tentatively identified as oxymorphone, was found to be excreted in conjugated form. From 33–61% of a single oxycodone dose was excreted in the 24-hour urine of two subjects as free (13–19%) and conjugated oxycodone (7–29%) and conjugated oxymorphone (13–14%). A second metabolite was observed by thin-layer chromatography, but was not identified.