THIN-LAYER CHROMATOGRAPHIC DETECTION OF COCAETHYLENE IN HUMAN URINE

A thin-layer chromatographic method was developed for the detection of cocaethylene and cocaine in human urine. Following a standard solid-p hase extraction of urine buffered to pH 9.3, the concentrated extract was chromatographed in a solvent consisting of hexane:toluene:diethyla mine (65:20:5 mL). Both cocaethylene and cocaine were visualized with iodoplatinate spray. Exclusive of the type of extraction used, the det ection limit itself was 16 nmol (5 mu g) for either compound. The meth od was applied to urine samples of 13 patients who had ingested cocain e with ethanol. Statistically significant correlations were noted betw een the intensity of the urine thin-layer chromatographic detection an d the measured urine concentrations of cocaethylene and cocaine. The p lasma and urine concentrations of both drugs also showed statistically significant correlations. Incorporation of the proposed procedure int o commonly used clinical laboratory methodology is described.