Urine cannabinoid analysis: an integrated multi-method approach.

The Enzyme Multiplied Immunoassay Technique (EMIT) Urine Cannabinoid Assay (Syva) was adapted for automated analysis on a centrifugal analyzer allowing for cost-effective, rapid, high-volume urine testing. Confirmation of positive EMIT results was accomplished by a modification of a recently published high performance liquid chromatographic (HPLC) technique for 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid (THC-COOH). Further confirmation of the presence of THC-COOH was achieved by high efficiency thin layer chromatography (HETLC). The reported protocol was applied to urine samples obtained from an emergency toxicology population and a drug counseling population. Results indicated that specimens testing positive by all three methods suggest valid forensic evidence for the presence of THC-COOH.