Rapid determination of conditional partition constants in an FIA system

This paper presents a simple and rapid method for the screening of substances for their conditional partition constants in the chloroform-water system. Samples are injected in either aqueous or organic solution into the corresponding phase. After equilibration in segmented flow the amount of sample remaining is measured photometrically. Performing the measurements at a series of phase volume ratios enables calculation of conditional partition constants knowing neither the amount injected nor the absorptivity of the substance under study. The time needed for a determination is about 15 min per substance, in many cases even shorter and the sample consumption is, in most cases, less than 1 mg. These characteristics make the method suitable for screening purposes. A series of compounds has been examined with this method, and acceptable results for the conditional partition constants were obtained in the range 0.2 less than D' less than 100 (-0.7 less than log D' less than 2.0).