Evaluation of Acetonitrile Deproteinisation of the Serum Samples for the Analysis of Drugs in Serum Using Capillary Zone Electrophoresis

Deproteinisation with acetonitrile (along with methanol or other reagents) is a useful and rapid technique in analysis of drugs or their metabolites in human serum. In this paper application of this simple technique in biopharmaceutical analysis using capillary electrophoresis (CE) is evaluated. Some drugs with different ionic and protein binding properties were selected and dissolved in human serum. The efficiency of deproteinisation of spiked serum samples with acetonitrile and further analysis with CE was evaluated for each sample with special interest on the neutral drugs. The results showed that deproteinisation method is more efficient for charged molecules with low protein bindings. For neutral, relatively non-polar compounds (such as praziquantel), a MEKC method is preferred. For neutral, highly polar molecules (such as methimazole) other means of sample preparation must be considered.