Thin-layer chromatographic detection and identification of methaqualone metabolites in urine

A procedure for detecting methaqualone and identifying methaqualone metabolites in urine by thin-layer chromatography is described and evaluated. Urine is hydrolyzed with HCl or NaIO4, adjusted to pH 9.5, and extracted with chloroform. The chloroform extract is evaporated, reconstituted in methanol, applied to fluorescent silica-gel plates, and developed with ethyl acetate:methanol:ammonium hydroxide (28%) (85:10:5 by vol). Methaqualone use is detected by a pattern of four metabolites, which can be seen under ultraviolet light or are made visible by acidified iodoplatinate reagent. Synthetic methaqualone metabolites are used for identification and to compensate for procedural variables. More than 250 positive urine specimens were correctly identified by this method. Hydrolyzed natural and synthetic metabolites were identical by several criteria.