A simple method for the routine determination of quercetin in biological samples was developed. The method consists of hydrolysis of bonded quercetin, its isolation and preconcentration on solid-phase extraction (SPE) column and a final analytical step using micellar electrokinetic capillary chromatography. The working range, linear range, the limit of quantification, and the measurement uncert...

A simple and sensitive on-chip preconcentration, separation, and electrochemical detection (ED) method for the electrophoretic analysis of food dyes was developed. The microchip comprised of three parallel channels: the first two are for the field-amplified sample stacking (FASS) and subsequent field-amplified sample injection (FASI) steps, while the third one is for the micellar EKC with ED (M...

Capillary electrokinetic separation techniques offer high efficiency and peak capacity, and can be very useful for the analysis of samples containing a large variety of (unknown) compounds. Such samples are frequently met in impurity profiling of drugs (detection of potential impurities in a pharmaceutical substance or product) and in general sample profiling (determination of differences or si...

The report of methicillin-resistant Staphylococcus aureus (MRSA) encoding a divergent mecA gene in 2011 was highly significant. This homologue, designated mecC, poses diagnostic problems with the potential to be misdiagnosed as methicillin-sensitive S. aureus, with important potential consequences for individual patients and for the surveillance of MRSA. mecC MRSA have now been reported from 13...

We report on the application of sweeping-MEKC, for the first time, using the Environmental Protection Agency Method 8330 stock standard (a mixture of 14 explosives). The use of a traditional MEKC mode provided the LODs (at S/N=3) ranging from 1.5 to 2.9 microg/mL for the 14 explosives standards, which were improved by as low as 3.1-6.5 ng/mL when a sweeping-MEKC technique was used. A set of 21 ...

The aim of the present study was to examine the effect of micellar systems on the absorption of beta-lapachone (b-lap) through different intestinal segments using a single-pass rat intestinal perfusion technique. B-lap was solubilized in mixed micelles composed of phosphatidylcholine and sodium deoxycholate, and in sodium lauryl sulfate (SLS)-based conventional micelles. Both mixed micelles and...

Micellar electrokinetic chromatography (MEKC) has been applied for the determination of 5-hydroxymethylfurfural in several foodstuffs. A 75mM phosphate buffer solution at pH 8.0 containing 100mM sodium dodecylsulphate was used as background electrolyte (BGE), and the separation was performed by applying +25kV in a 50μm I.D. uncoated fused-silica capillary. Good linearity over the range 2.5-250m...

The optical properties (absorption and fluorescence) of fluorescein sodium were investigated with changing the bulk pH value in aqueous, water-methanol mixed and dodecylammonium propionate reversed micellar solutions. A strong buffer action was found in the reversed micellar solutions. The pK a values for the equilibrium between fluorescein monoand di-anions in the ground and excited singlet st...