The capillary electrophoresis separation of benzodiazepine drug using dextran sulfate and SDS as running buffer

Abstract

Capillary electrophoresis has been applied the analyses of many clinical drugs due to its rapid, high-resolution separation. In this study, electrokinetic chromatography involving the combination of SDS and dextran sulfate, which are synthetic polymers, was examined in order to obtain high resolution. Use of 2% dextran sulfate (10,000 molecular weight), 20 mm SDS running buffer containing boric acid solution (pH 9.2) and a silica capillary (inner diameter of 75 micro m, effective length of 50 cm, 57 cm overall length) afforded separation of 10 kinds of benzodiazepines. The detection limit was 0.2 micro g/mL; additionally, reproducibilities were de fi ned as the peak height and migration time. The average peak height was 5.92% (2.46-17.61), whereas the average migration time was 0.44% (0.18-0.76; n = 5). This separations system can be applied to the analysis and measurement of other pharmaceuticals as well.

Response surface methodology for the modelling of copper removal from aqueous solutions using micellar-enhanced ultrafiltration

“…The regenerated cellulose membrane with 10,000 was applied since according to theory the feed solution contains bigger aggregates (polymer-surfactant micelles) comparing to surfactant micelles alone. It must be noted that SDS micelle has an aggregation number equal to 62 [30] so the micellar molecular weight is equal to 62 × 288.38 ∼ =18,000.…”

Quantification of chlordesmethyldiazepam by liquid chromatography–tandem mass spectrometry: application to a cloxazolam bioequivalence study

“…Numerous protocols for CDDZ determination considering different purposes and techniques have been reported: forensic (Miyaguchi et al, 2006), pharmaceutical (Ellaithy et al, 2001;Suzuki et al, 2004), environmental (El-Baqary et al, 2007), drug monitoring and pharmacological (Otsubo et al, 1995;Inoue et al, 2000;Aresta et al, 2002;Laloup et al, 2005;Stanley and Foo, 2006). However, these articles present limited throughput and restrict sensitivity.…”

A rapid CZE method for the analysis of benzodiazepines in spiked beverages

“…The EOF decreases rapidly below pH 6 and, at pH 2-3, it is almost completely eliminated, resulting in increased analysis times for cationic compounds [12]. Considering this, and given the low pK a 's of benzodiazepines, which makes them difficult to ionise and therefore difficult to analyse by CZE, the majority of benzodiazepine analyses are performed with micellar EKC (MEKC) [13][14][15][16][17][18][19][20]. CEC on octadecyl stationary phases [21] and on novel stationary phases based on modified silyl silica gel [22] have also been developed.…”