An Evaluation of Selected Methods for Determining Cocaine and Benzoylecgonine in Urine

Abstract

Four analytical techniques, chromatographic and immunologic, were evaluated for their ability to detect cocaine and its metabolite benzoylecgonine in human urine. Each of the methods had advantages end limitations and was suited for specific laboratory requirements. The study showed that gas-liquid chromatography was the most precise method; thin-layer chromatography, the most applicable for determining a number of drugs simultaneously; and enzyme immunoassay, the method with the best turn-around time for analyzing small numbers of specimens. Radioimmunoassay was significantly the most sensitive method for both cocaine and benzoylecgonine and the most efficient for the analysis moderate to large numbers of specimens. Comprehensive evaluation studies were performed with a radioimmunoassay technique that has only recently been made available.