Analysis of toxic drugs by capillary electrophoresis using polyacrylamide-coated columns

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.