COMPARISON OF A TLC METHOD WITH EMIT AND GC MS FOR DETECTION OF CANNABINOIDS IN URINE

Urine specimens were analyzed in parallel with a new TLC method, an EMIT® assay, and a reference GC/MS method. At a 9-carboxy-THC cutoff of 20 ng/mL, the TLC method correctly identified 92% of the positive urines and 97% of the negative urines. In contrast, only 63% of the urine specimens shown by GC/MS to contain greater than 20 ng/mL of 9-carboxy-THC were identified as positive by the EMIT d.a.u. assay at the 100-ng/mL cannabinoid cutoff. © 1990 Oxford University Press.