TEMPERATURE PROGRAMMING IN OPEN-TUBULAR LIQUID-CHROMATOGRAPHY

We have examined the separation of test mixtures by linear and step te mperature gradients in open tubular capillary liquid chromatography, i n reverse and normal-phase modes. Separations using temperature gradie nts with the upper temperature limit of 433 K were compared to isother mal runs in terms of chromatographic efficiency, analysis time and sel ectivity. When a temperature gradient (363 K to 433 K in 12 min) was u tilized in reverse phase separation of chlorobenzenes, a 40 % reductio n in analysis time, compared to an isothermal separation at 363 K, was accomplished.