Detection of cannabinoids in blood using EMIT

A procedure for the detection of cannabinoids in blood (1 mL) using enzyme multiplied immunoassay technique (EMIT) is described. The sensitivity of the method, determined using 11-nor-delta 8-THC-9-carboxylic acid is better than 20 ng/mL. Estimates of precision and a study of storage effects show the method is applicable to blood samples normally encountered in toxicology casework. The method should be useful in screening and selecting blood samples for more specific confirmational procedures.