Simultaneous determination of vitamin A,D_3 and E in infant formula milk powder and rice flour by two-dimensional liquid chromatography / double detector

The aim was to establish a simultaneous determination method for infant formula milk powder and infant rice in vitamin A,D_3 and E using line two- dimensional liquid chromatography.At first,to choose ultra- efficient C_(18) and C_(18) bonded polymeric bonded phase column PHA used as one- dimensional and two- dimensional separation column separately. One dimension with methanol and water acted as the mobile phase by reverse- phase chromatography method,and the two- dimension with acetonitrile and isopropanol as the mobile phase. Using quaternary LC pump as a one- dimensional analysis,complete quantitative of vitamin A,E and purification of vitamin D_3. The other two binary pumps put vitamin D_3 fraction in SPE column to a two- dimensional chromatographic column and to complete quantitative analysis of vitamin D_3. Run the entire two- dimensional chromatographic system consists of two pumps driven chromatography with high degree of automation,only a six- way valve was switched,and the detection time was short,only 10 minutes to complete separation of all the peaks.3 kinds of vitamins of infant formula and infant formula rice were detected under these optimal conditions.The standard addition recovery of vitamin D_3 by this method was 90.1% to 99.7%.And the measured results were compared with the national standard method that suggest that vitamin A,D_3 and E deviations were small and < 5%.It was showed that the method was simple,fast and accurate.