[The identification of ephedrine and its analogues in urine by gas chromatography].

A sensitive and reliable method of analysis for ephedrine and its analogues was established by using GC and GC-MS. The columns used for both GC and GC-MS were HP-5, and the carrier gas was helium. NPD was used as the detector for GC. The urine sample was extracted with ether and submitted to GC. If positive, it was then submitted to GC-MS to identify its structure. The detection limits for ephedrine and its analogues are lower than 200 ng/ml urine. The recoveries are above 80%.