Thin-layer chromatographic screening procedure for some drugs in horse plasma

A thin-layer chromatographic screening procedure for some basic, neutral and acidic drugs was developed using 3 ml of horse plasma. Chloroform-2-propanol (95:5, v/v) was used as the extraction solvent. The drugs were identified by a high-performance thin-layer chromatographic plate and spraying successively with some detection reagents. In this study, the extraction recovery rates and the detection limits were determined at the same time.     

Thin-layer chromatographic screening and confirmation of basic drugs of abuse in urine.

Thin-layer chromatographic procedures are presented for the positive identification of methodone, primary metabolite of methodone (2-ethylidine-1,5-dimethyl-3,3-diphenylpyrrolidine), propoxyphene, norpropoxyphene, cocaine, benzoylecgonine, methoqualone, and phencyclidine from urine specimens. Initial screening of specimens is done by developing plates in ethyl acetate-methanol-diethylamine (90:10:1.6). Samples screened positive are confirmed in methylene chloride-methyl ethyl ketone-concentrated ammonium hydroxide (74:25:0.8), depending on the drug(s) indicated by the screening procedure. The method is quite sensitive, detecting most of the listed drugs at levels of 1.0 mug/ml or less.     

Thin-layer chromatographic screening procedure for undeclared synthetic drugs in Chinese herbal preparations

A simple and rapid thin-layer chromatographic procedure was developed for the detection and presumptive identification of seventeen synthetic drugs previously reported as adulterants of Chinese herbal preparations. Depending on its complexity, the sample may be directly extracted into aqueous ethanol, or stepwise fractionated into acidic, basic, and neutral components. Extracts are analyzed on silica gel layers containing a fluorescent indicator with the aid of two solvent systems. Spots are visualized under short and long wavelength ultraviolet lights. The procedure was successfully tested on synthetic and commercial samples.     

Thin-layer chromatographic separation and identification of some anions on copper sulphate impregnated silica gel layers

Summary Thin-layer chromatographic behaviour of thirteen anions on plain silica gel and silica gel impregnated with copper sulphate solution has been investigated in aqueous-organic solvents containing acetone, some of which have achieved reliable and reproducible separations. The effect of copper sulphate concentration on the mobility of anions has been examined. The results obtained on plain silica gel have been compared with those obtained on copper sulphate impregnated layers. The impregnated layers dramatically change the selectivity and permit separations not possible on untreated silica. Aqueous sodium chloride-acetone (9∶1) and ammonium hydroxide-acetone (9∶1) were the most effective solvent systems for differential migration of anions. Better results in terms of clarity of detection and compactness of spots were found with HCOOH-acetone as compared to HCl-acetone. The effect of anion loading on R_F values has been investigated and identification limits on impregnated layers determined.