Quantitation of cocaine and benzoylecognine after JETUBE extraction and derivitization

A procedure is described for the extraction of cocaine and benzoylecognine from whole blood using a modified JETUBE procedure in which only one-fourth of the JETUBE is used for the extraction. The benzoylecognine is derivitized using 0.025 mol/l tetrabutylammonium hydrogen sulfate (TBAHS) in 0.2 mol/L trimethylanalinium hydroxide (TMAH) and ethyl iodide at 100 degrees C for 8 minutes to given its corresponding ethyl ester. Cocaine and ethylbenzoylecognine are then quantitated on a gas chromatograph, equipped with a nitrogen-phosphorous detector (NPD), using the propyl ester of benzoylecognine as the internal standard. Twenty forensic toxicology cases are presented that were quantitated for cocaine and benzoylecognine. In the cases where the cause of death was not directly attributable to cocaine, only benzoylecognine was found.