Combined high-performance liquid chromatography and radioimmunoassay method for the analysis of delta 9- tetrahydrocannabinol and its metabolites in plasma and urine.

A high-performance liquid chromatography-radioimmunoassay method for the measurement of cannabinoids in plasma and urine is described. The experimental procedure consists of chromatographing a plasma extract or hydrolysed urine sample by high-performance liquid chromatography and quantifying the eluting cross-reacting cannabinoids with radioimmunoassay. The concentrations of delta 9- tetrahydrocannabinol (THC), cannabinol, mono-hydroxylated metabolites, di-hydroxylated metabolites, delta 9-THC-11-oic acid, and delta 9-THC-11-oic acid ester glucuronide may be measured by this technique.