TY - JOUR AU - Heineman, William R AB - A rapid approach for estimating the pK(a) value of small organic molecules was developed using vacuum-assisted multiplexed capillary electrophoresis (VAMCE) with ultraviolet detection. The VAMCE method employed a 96-capillary array, arranged in a standard 8 x 12 microtiter plate configuration, with each row of capillaries filled with 12 individual running buffers of equal ionic strength (I = 50 mM) covering a pH range from 2.2 to 10.7. A separate compound was injected hydrodynamically into each row of capillaries allowing the estimation of pK(a) values for eight compounds in a single run. The application of a vacuum during the separation generated a bulk fluid flow and allowed the electrophoretic separation to be completed within 5 min. The complete VAMCE method, conditioning, and electrophoretic separation was optimized to allow the pK(a) estimation for between 128 to 168 compounds in an 8-h period. The VAMCE method provided a reliable approach for estimating pK(a) values both within- and between-day. The pK(a) values for a series of 96 compounds estimated by VAMCE agreed well with some of literature pK(a) values with an average absolute difference of 0.22 log units. TI - Rapid pKa estimation using vacuum-assisted multiplexed capillary electrophoresis (VAMCE) with ultraviolet detection. JF - Journal of Pharmaceutical Sciences DO - 10.1002/jps.20275 DA - 2005-07-21 UR - https://www.deepdyve.com/lp/pubmed/rapid-pka-estimation-using-vacuum-assisted-multiplexed-capillary-UcEU6gn9rs SP - 576 EP - 589 VL - 94 IS - 3 DP - DeepDyve ER -