Identification and determination of ephedrine and its congeners in urine by gas chromatography

Abstract

A sensitive and specific assay for ephedrine-type compounds in urine is described. The procedure involves the removal of neutral and acidic compounds, then extraction of the bases with ether. This extract, after concentration, is injected into a flame ionisation gas chromatograph equipped with a 2% polyethylene glycol 6000, alkaline treated, column at 165°. Linear detector response between 5 and 100 μg base/ml urine was observed (peak height with respect to an internal marker) and replicate analyses indicated good reproducibility. No interfering compounds have been encountered nor any “on column” decomposition. The amines were further identified by chromatography of their acetone derivatives.