Capillary electrophoretic separation of toxic drugs using a polyacrylamide-coated capillary

Abstract

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.

Miniaturized Sample Preparation and Separation Methods for Environmental and Drug Analyses

“…Combination of SPME preconcentration with MEKC separation was also examined 26,27 for the analysis of benzodiazepines. The SPME fiber was exposed to a 10 mL 13 ANALYTICAL SCIENCES JANUARY 2002, VOL.…”

Liquid-phase microextraction and capillary electrophoresis of acidic drugs

“…As an alternative to incapillary preconcentration, small sample volumes with a high sample-to-acceptor phase may allow solid-phase microextraction (SPME), where the drugs are preconcentrated into a very small solid polymeric phase of, e.g., polydimethylsiloxane [6±8]. SPME may be carried out both in the off-line mode [6,7] or on-line with a direct SPME-CE interface [8], but both concepts are of low popularity in combination with CE.…”

Poly(methacrylic acid‐ethylene glycol dimethacrylate) monolith in‐tube solid‐phase microextraction applied to simultaneous analysis of some amphetamine derivatives in urine by capillary zone electrophoresis

“…Also, an automated procedure has been used to concentrate and determine a tryptic digest of bovine serum albumin [37]. On-column interfaces for coupling SPME to CE have been constructed and evaluated for phenols [38] and antidepressant drugs [39]. Some advantages of on-line preconcentration methods compared with off-line ones are the speed, automation, and low detection limit [40][41][42].…”