ASSESSMENT OF AUTOMATED CAPILLARY ELECTROPHORESIS FOR THERAPEUTIC AND DIAGNOSTIC DRUG-MONITORING - DETERMINATION OF BUPIVACAINE IN DRAIN FLUID AND ANTIPYRINE IN PLASMA

In an effort to evaluate the use of electrokinetic capillary technology for therapeutic and diagnostic drug monitoring, samples were analysed batchwise with an automated, high-throughput capillary electrophoretic instrument coupled to an inexpensive PC data acquisition and evaluation system. Examples studied included the capillary electrophoretic (HPCE) determination of bupivacaine in drain fluid collected after pulmonary surgery and the micellar electrokinetic capillary chromatographic (MECC) determination of antipyrine in human plasma. Analyses for antipyrine could be accomplished without any sample pretreatment whereas bupivacaine required extraction prior to analysis. Antipyrine determination was effected through external calibration using either peak areas, relative peak areas or peak heights. The intraday and interday reproducibilities (n = 15) of the evaluated concentrations were 1.5-3% and 5-6%, respectively. For bupivacaine, determination based on internal and external calibration employing peak areas and peak heights was investigated. The intraday and interday reproducibilities (n = 5) of bupivacaine concentrations were about 1% and 2%, respectively, for internal calibration and both about 5% for external calibration. The electrokinetic capillary data compared well with data obtained by gas chromatography (bupivacaine) and high-performance liquid chromatography (antipyrine).