COMPUTER-AIDED IDENTIFICATIONS OF THIN-LAYER CHROMATOGRAPHIC PATTERNSIN BROAD-SPECTRUM DRUG SCREENING

We have developed a systematic thin-layer chromatographic (TLC) techni que for detecting and identifying drugs and drug metabolites on 10-cm- long silica-gel plates with organic binder (fluorescent indicator); a computer program (SPOT CHEK) assists in matching the data from a parti cular chromatogram with those obtained for known drugs recovered from serum, urine, or other specimens. The plates are developed in a single mobile phase. Visualization and detection reagents used to characteri ze unknowns include fluorescamine, ferric chloride/perchloric acid/nit ric acid, Dragendorff, Marquis, Mandelin, and iodinated Dragendorff so lutions, 254 nm ultraviolet light, and vapor from chlorine or hydrochl oric acid. Detection limits of 5-200 ng per sample spot were obtained for drugs in the database. The computer program database is based on n ine reaction responses plus the plate zone locations for 243 drug subs tances but requires entry of only one TLC property to generate a match ing list. We ran the program with an IBM-compatible 386/486 PC using a n MS-DOS operating system (version 6.2).