Cocaine Exhibits Containing Diltiazem

A new, highly specific color test for the screening/presumptive identification of diazepam is reported. The test is a variant of the McKibben test for flunitrazepam. Treatment of diazepam with alkaline dimethylsulfoxide produces a reddish color which gradually changes to yellow with passage of time. The color instantly vanishes upon addition of water or attempted extraction with organic solvents, suggesting that the color is due to a transient charge-transfer complex. Somewhat unexpectedly, the test does not produce color with powder scraped from diazepam-containing tablets in such cases, a chloroform extraction is required. The test is negative for other controlled substances, including other benzodiazepines, and also for various diluents and binders typically present in tablets (62 compounds were tested). The LODs were 20 :g for diazepam extracted from tablets, and 2 :g for diazepam standard. The test is particularly useful for the rapid screening of illicit Lemmon 714 (Quaalude) mimic tablets, which contain diazepam as a substitute for methaqualone.