Specificity of the cannabinoid metabolite and phencyclidine EMIT d.a.u. assays

An investigation to determine the specificity of the EMIT d.a.u. assays was conducted. Samples of drug-free urine from healthy volunteers were spiked individually with one of 162 drugs to a concentration of 1000 mg/L. These samples were analyzed with the EMIT d.a.u. assays for phencyclidine and cannabinoids. Although some of the assays yielded positive results at this concentration, negative results were obtained in all samples diluted to 100, 10, and 1 mg/L.