Detection and confirmation of cocaine use by chromatographic analysis for methylecgonine in urine.

Methylecgonine is a common metabolite of cocaine in man. We prepared methylecgonine and developed thin-layer chromatographic and gas-chromatographic methods for its detection in urine. Seventy urine specimens from our drug screening laboratory were tested by our method and by EMIT. Both methods were positive for 26 urines, and both were negative for 42 urines. The other two urines were shown to contain cocaine by GC/MS, and no detectable metabolites. We thus demonstrated that detection of methylecgonine and cocaine is as sensitive a test for cocaine use as EMIT.