A micellar electrokinetic chromatography(MEKC) with multiwavelength switching was established for the simultaneous determination of vitamin B1

B2

B6

nicotinamide

calcium pantothenate and sodium benzoate in Five Vitamins Oral Solution.Factors affecting separation efficiency such as detection wavelength

concentration of sodium dodecyl sulfate(SDS)

separation voltage of sample

pH value and concentration of background buffer were optimized．An optimal separation of six compounds was obtained on an uncoated fused silica capillary column(75 μm×50 cm

effective length 42 cm)

with a background buffer composed of 40 mmol/L borax+40 mmol/L boric acid+20 mmol/L SDS(pH 9.0)

at a separation voltage of 20 kV and a column temperature of 25 ℃.The detection wavelength was set at 270 nm for vitamin B1

B2

B6

nicotinamide and sodium benzoate

and 200 nm for calcium pantothenate.The sample was electrokinetically injected at 10 kV for 10 s.Results indicated that the six analytes could be separated within 13 min

while their calibration curves showed good linear relationships in the respective concentration ranges

with correlation coefficients(r) not less than 0.998 9.The average recoveries at three spiked levels ranged from 97.0% to 103%

with relative standard deviations(RSD) of 0.60%-1.8%.The method is rapid

accurate and reliable

and could be used for the determination of vitamin B1

B2

B6

nicotinamide

calcium pantothenate and sodium benzoate in Five Vitamins Oral Solution.