Propoxyphene and norpropoxyphene quantitation in the same solid-phase extraction using Toxi-Lab Spec VC MP3 system.

We have found that in using the Toxi-Lab Spec VC MP3 column we were able to easily identify and quantitate both propoxyphene and the major metabolite, norpropoxyphene, in a single extraction using urine as a matrix. Samples were screened using the Syva EMIT d.a.u. 1.0 assay for propoxyphene on the Olympus 5131, and all presumptive positives were prepared for confirmation by gas chromatography-mass spectrometry on Hewlett-Packard instruments. Urine (1.0 mL) was extracted and treated with a strong base (pH 11.0) in order to rearrange, by base catalysis, norpropoxyphene to norpropoxyphene amide, which chromatographs well on these columns.