Determination of cocaine and benzoylecgonine by derivatization with iodomethane-D3 or PFPA/HFIP in human blood and urine using GC/MS (EI or PCI mode).

A method for the simultaneous detection and quantification of cocaine and benzoylecgonine from human blood and urine has been developed. Cocaine and benzoylecgonine were extracted from blood and urine with solid-phase columns containing C18 packing material. Clean, emulsion-free extracts were obtained. The analytes were derivatized with PFPA/HFIP or iodomethane-D3. The underivatized cocaine and derivatized benzoylecgonine were determined by GC/MS with positive chemical ionization (PCI) and the selected ion monitoring mode. Benzoylecgonine was derivatized with iodomethane-D3 to cocaine-D3. Both derivatives were chromatographed on a CP-SIL 5 capillary column. The recovery of extraction was greater than 70%. The detection limit for the PFPA/HFIP derivatives (20 ng/mL) was better than that for iodomethane-D3 derivatives (40 ng/mL). The procedure is simple, rapid, and reproducible. Standard curves were linear and the procedure was suitable for routine analysis. Using fluorescence polarization immunoassay (TDx, Abbott) (cutoff 100 ng/mL), along with one of the GC/MS methods described, we found no false positive or false negative results.