Identification of unique cocaine metabolites and smoking by-products in postmortem blood and urine specimens.

Toxicological investigation of suspected cocaine-related deaths routinely involves the identification of cocaine (COC) and its metabolites including benzoylecgonine (BE) and ecgonine methyl ester (EME) in postmortem specimens. We utilized solid-phase extraction followed by gas chromatography/mass spectrometry for the qualitative and quantitative analysis of cocaine and eight cocaine-related analytes. These analytes included anhydroecgonine methyl ester (AEME), a unique product formed during cocaine smoking, and cocaethylene (CE), formed by transesterification of cocaine in the presence of ethanol. Thirteen pairs of postmortem heart blood and urine specimens were analyzed from cases of death due to acute cocaine intoxication, multiple drug intoxication, or other non-drug related causes. COC, EME, and BE were detected in all specimens. The range of concentrations in blood were: COC, 23-2088 ng/mL; BE, 215-9195 ng/mL; and EME, 220-7275 ng/ mL. AEME was identified in 2 blood and 10 urine specimens, and CE was identified in 1 blood specimen and 4 urine specimens. The identification of AEME in the specimens indicated that "crack" cocaine had been smoked, and the presence of CE indicated co-administration of cocaine and ethanol. The presence of these unique cocaine analysis in postmortem specimens provides valuable information regarding the cause and manner of death.