Comparative evaluation of the performance of silica gel TLC plates and irregular and spherical-particle HPTLC plates

Commercial precoated thin-layer chromatography (TLC) and highperformance TLC (HPTLC) plates with spherical or irregular particles have been compared on the basis of theoretical plate number (N), resolution (R), linearity, development time, and limit of sensitivity for analysis of a multicomponent analgesic tablet in the fluorescence quenching mode and analysis of a five-component dye mixture in the visible mode. Standardized plate preparation, sample application, and development procedures were used, and separations were conducted over the usual development distances of 12.0 cm for TLC and 6.0 cm for HPTLC. It was found that TLC often gave the best N and R values, but that development time, sensitivity, and linearity were better for HPTLC. Spherical-particle HPTLC plates performed better for the drug mixture and irregular HPTLC plates performed better for the dye mixture. Some results are also given for preadsorbent irregular-particle HPTLC and ultra-TLC plates.