Microcrystalline identification test of some amphetamines and hydrochlorothiazide: collaborative study

A previously described procedure for the identification of methamphetamine, dl-deoxyephedrine, dextroamphetamine, and amphetamine and a new procedure for hydrochlorothiazide identification have been subjected to collaborative study. The method for the amphetamines depends upon their volatilization from a strongly basic solution into a hanging drop containing gold chloride and the formation of characteristic crystals. The hydrochlorothiazide method is direct: the I2-KI solution is added to an alkaline solution of hydrochlorothiazide to cause the deposition of characteristic crystals. Of the 40 unknown drug dosage form powders supplied to 10 collaborators, 39 were correctly identified. The results indicate that the amphetamine procedure is capable of distinguishing between methampetamine and dl-deoxyephedrine. The age of the gold chloride reagent is important in these tests. The official final action tests for dl-deoxyephedrine and methampetamine were modified and Table 36:04 has been revised to reflect these changes. The hydrochlorothiazide test has been adopted as official first action and added to Table 36:05.