Separation of gliadins from wheat flour by capillary gel electrophoresis: optimal conditions

Introduction. Gliadin proteins are one of the gluten fractions. They are soluble in alcoholic solution and divided into four groups (α + β, γ, ω1.2, and ω5-gliadins). In this paper gliadins were extracted from wheat flour, and optimal conditions for their separation were determined. Study objects and methods. The separation was performed by capillary gel electrophoresis on Agilent apparatus, CE 7100 (a capillary with an inner diameter of 50 μm, a total length of 33 cm, and an effective length of 23.50 cm). In order to determine the optimal conditions, different solvent concentrations (50, 60, and 70% ethanol), capillary temperatures (20, 25, 30, 35, and 40°C), and electrode voltages (–14.5, –16.5, –17.5 and –18.5 kV) were applied. Migration time and relative concentration of each protein molecules within gliadin fractions in the electrophoregram were analysed using Agilent ChemStation Software. Results and discussion. The optimal conditions for gliadin separation were: solvent 70% (v/v) ethanol, capillary temperature of 25°C, and electrode voltage of –16.5 kV. Under these conditions, the total proteins were indetified as Xav = 23.50, including α + β gliadin fraction (Xav = 7.50 and relative concentration RC = 28.29%), γ-gliadins (Xav = 5.00, RC = 26.66%), ω1.2-gliadins (Xav = 4.33, RC = 14.93%), and ω5-gliadins (Xav = 6.67, RC = 30.98%). Conclusion. The results of the research can be of fundamental importance in the study of gluten proteins and the influence of technological procedures on their change and the possibility of reducing the allergic effect of gluten during processing.

X-ray powder diffraction for charge density studies

Issues concerning optimal powder diffraction at synchrotron sources for charge density studies will be discussed. These include beam qualities (energy, bandwidth, brillance, flux) as well as sample environmnet (vaccuum, capillary, temperature) and detector type (image plate, crystal analyzer). Simple on-line analysis in obtaining structure factors will be presented.

Development of a Capillary Electrophoresis Method for the Enantioselective Estimation of Primaquine in Pharmaceutical Formulations

A capillary electrophoresis (CE) method has been developed that allows the separation and estimation of primaquine enantiomers using hydroxypropyl--cyclodextrin (HP--CD) as a chiral selector. The influence of chemical and instrumental parameters on the separation, such as type and concentration of CD, buffer concentration, buffer pH, applied voltage, capillary temperature, and injection time, were investigated. Good separation of the racemic mixture of primaquine was achieved using a fused-silica capillary (52.5 cm effective length 50 m id) and a background electrolyte composed of tris-phosphate buffer solution (50 mM, pH 2.5) containing 15 mM HP--CD as a chiral selector. The recommended applied voltage, capillary temperature, and injection time were 15 kV, 25C, and 6 s, respectively. Within-day and interday reproducibility of peak area and migration time gave relative standard deviation values ranging from 1.053.30. Good recoveries (range of 96.8104.9) were obtained from the determination of placebos that were spiked with 0.251.00 mg/L primaquine. The proposed CE method was successfully applied to the assay of primaquine diphosphate in pharmaceutical formulations (tablets).