Application Of NanoLatex Coated Columns In Capillary Electrophoresis For Pharmaceutical And Food Analysis

Open tubular capillary electrochromatography(OT-CEC) is one of the most important methods in capillary electrochromatography(CEC). Nanoparticles(NPs) with high surface-to-volume ratio, have been successfully used as coating materials for OT-CEC. In this work, dimethylethanolamine aminated polychloromethyl styrene nanolatex and triethylamine aminated polychloromethyl styrene nanolatex coated capillary columns were successfully prepared and characterized. Compared with the bare column, the EOF values of these two kinds of nanolatex coated capillary columns were lower and more steady. On the basis of these advantages, the coated nanolatex columns were used as analytical column in electrophoresis analysis.1. Dimethylethanolamine aminated nanolatex and triethylamine aminated nanolatex coated capillary columns were prepared. And they were characterized from diameter, infrared absorption, EOF values, reproducibility and stability. From the characterization results, the modified columns were successfully prepared.2. The dimethylethanolamine aminated nanolatex coated column was used as analytical column by field amplified sample stacking method in capillary electrophoresis to determination of dopamine. The optimized determination conditions were as following: background electrolyte, 20 mmol L-1 HAc + 20 mmol L-1 Na Ac(p H 4.54); the coated capillary columns, 50 μm i.d. × 50 cm(effective length 41.5 cm); separation voltage, 13 k V; column temperature, 25 °C;UV detection wavelength, 224 nm; water-plug injection: 30 mbar × 10 s; sample electrokinetic injection, 20 k V × 25 s. Under the optimized conditions, the dopamine was analysis within 6 min, and the detection limits were 2 ng m L-1. The results demonstrate that the developed method is a simple, rapid, sensitive and inexpensive method for the determination of dopamine in real samples.3. The dimethylethanolamine aminated nanolatex coated columns was used as analytical column by field amplified sample stacking method in capillary electrophoresis to determination of three kinds of macrolide antibiotics. The optimized determination conditions were as following: background electrolyte, 10 mmol L-1 Na H2PO4 + 40 mmol L-1 Na2HPO4(p H 7.42); the coated capillary columns, 50 μm i.d. × 50 cm(effective length 41.5 cm); separation voltage, 20 k V; column temperature, 25 °C;UV detection wavelength, 210 nm; water-plug injection: 50 mbar × 10 s; sample electrokinetic injection, 13 k V × 20 s. Under the optimized conditions, three macrolide antibiotics were well separated within 5 min(Rs > 1.5), and the overall recoveries were more than 82.0%. The results demonstrate that the developed method is a simple, rapid, sensitive and inexpensive method for the determination of three kinds of macrolide antibiotics in real samples.4. The triethylamine aminated nanolatex coated columns was used as analytical column by field amplified sample stacking method in capillary electrophoresis to determination of benzoic acid and sorbic acid. The optimized determination conditions were as following: background electrolyte, 50 mmol L-1 Tris + 43 mmol L-1 HCl(p H 7.87); the coated capillary columns, 50 μm i.d. × 50 cm(effective length 41.5 cm); separation voltage,-25 k V; column temperature, 25 °C;UV detection wavelength, 224 nm; water-plug injection: 30 mbar × 10 s; sample electrokinetic injection,-15 k V × 20 s. Under the optimized conditions, benzoic acid and sorbic acid were well separated within 5 min(Rs > 1.5), and the detection limits were 12 ng m L-1 and 5 ng m L-1, respectively. The accuracy was tested by spiking standards in the soy sauce and vinegar samples, and the recoveries were 93.0%- 105.0 %. The results demonstrate that the developed method is a simple, rapid, sensitive and inexpensive method for the determination of benzoic acid and sorbic acid in the soy sauce and vinegar samples.