Thin layer chromatographic identification of phenothiazines in urine specimens

Two newly developed, thin layer chromatographic (TLC) solvent systems are presented to separate and identify commonly used phenothiazines in the presence of other drugs in urine specimens. These solvent systems are 1) ethyl acetate: n-butanol: concentrated ammonium hydroxide (89:10:1.5) and 2) ethyl acetate: O-dichlorobenzene: concentrated ammonium hydroxide (90:9:1.4). The phenothiazines are identified on the TLC plates both by Rf values and by colors produced with ethanolic sulfuric acid and palladium chloride sprays. With this method 0.025 mug/ml levels of unchanged phenothiazines can be detected in urine specimens.