SummaryCapillary electrophoresis (CE) has recently become an attractive approach for the analysis of pharmaceuticals. In this study, capillary electrophoretic separation of anxiolytic drugs, including barbiturates and benzodiazepines, was carried out using polyacrylamide (PAA)-coated capillaries. The surface of the capillary inner wall was coated with a neutral layer, and separation was performed in the absence of electroosmotic flow (EOF). Both charged and neutral solutes were separated in the presence of sodium dodecyl sulfate (SDS) above its critical micelle concentration (CMC) in the running buffer. This kind of CE method provided fast and efficient separation of a total of 24 kinds of toxic drugs in a mixture. In addition, the analysis of toxic drugs in body fluids was attempted after the sample preparation using liquid-liquid extraction or solid-phase microextraction (SPME).hydrophobicities in order to pass through the cell membrane easily and get into the blood stream to provide the most effective treatment. Even though in our earlier work [9] MEKC provided successful separation of these analytes with bare and C8-and C18-coated capillaries, the hydrophobic benzodiazepines were strongly partitioned into the micelles and thus required an extremely long analysis time. Therefore, we had previously developed [11] a rapid and efficient capillary electrophoretic separation method for these solutes using a capillary coated with linear polyacrylamide (PAA) as proposed by Hjert6n [10]. As had been pointed out [11], this kind of CE method gave a successful separation of 7 barbiturates in solution without further additives, and afforded a fast and efficient separation of some of the electrically neutral solutes (benzodiazepines) in presence of the charged SDS surfactant above its CMC in the running buffer. In this study, we will describe the capillary electrophoretic separation of a mixture of charged and uncharged solutes with the PAA-coated capillary in the MEKC mode. Furthermore, as application of this separation method, the analysis of some toxic drugs in body fluids was attempted after sample preparation using liquid-liquid extraction or solid-phase microextraction (SPME). The simple and rapid SPME preparation technique with a solvent-free procedure for extraction and concentration makes it possible to analyze trace level drugs in biological fluids by CE methods.

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Toxic drugs, including barbiturates and benzodiazepines, were analyzed using polyacrylamide-coated columns in capillary electrophoresis (CE). The separations were carried out in absence of electroosmotic flow. Seven kinds of barbiturates were successfully separated with the coated columns in free solution without further additives. Benzodiazepines, the electrically neutral solutes were introduced onto the coated column, and separated in presence of sodium dodecyl sulfate above its critical micelle concentration in the running buffer. This CE method offered fast and efficient separation of more hydrophobic solutes, such as benzodiazepines. The separation of seven barbiturates was studied in linear (noncross-linked) polyacrylamide solutions and in acrylamide/N-isopropylacrylamide (AA/IPAA) copolymer solutions to explore the effect of isopropyl groups in the AA/IPAA copolymer chain.

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