Abstract: A method using high performance liquid chromatography with diode array detector and fluorescence detector (HPLC-DAD-FLD) was established to simultaneously analyze seven water-soluble vitamins in starch-fortified foods. The sample was hydrolyzed by amylase at 60 ℃ for 45 min and ultrasonically extracted after pH adjustment. Chromatographic separation was carried out by gradient elution using 5 mmol/L sodium dodecyl sulfate solution containing 0.1% phosphoric acid adjusted to pH 3.0 with triethylamine as mobile phase A and acetonitrile as mobile B. Vitamin B1, niacin and nicotinamide were detected at maximum UV absorption wavelengths. Good linearity was observed for all analytes with correlation coefficients (r2) of 0.999 6–0.999 9. The recoveries for spiked samples were 90.5%–102.5%, the limits of detection (LODs) were 0.01-0.08 mg/100 g, and the limits of quantitation were 0.025–0.26 mg/100 g. The developed method is rapid, efficient and suitable for the simultaneous determination of the seven vitamins in bulk starch-fortified foods.

Key words: starch-fortified foods; water-soluble vitamins; high performance liquid chromatography with diode array detector and fluorescence detector; rapid determination