Simultaneous Determination of Vitamin B6,Nicotinamide and Calcium Pentothenate by RP-HPLC

The method of RP-HPLC was applied to simultaneous determination of vitamin B6,nicotinamide and calcium pentothenate in some vitamin nutriments. The sample was extracted ultrasonically with an extractant containing phosphate buffer solution (pH 3.0) and methanol for 5 min and then heated at 65-70 ℃ in a water bath for 10 min. The extract obtained was used for the HPLC analysis. The Inertsil pH-3 Phenyl column was used as stationary phase,and a mixed solution of 0.05 mol·L-1 KH2PO4,methanol and acetonitrile mixed in the ratio of 90 to 6 to 4 by volume,was used as mobile phase. UV detection was made at the wavelength of 210 nm. Linearity of the standard curves between the values of peak area and concentration of the 3 compounds was checked by regression analysis,giving values of correlation coefficients greater than 0.999 9. Test for recovery was made by standard addition method with a substantial sample as the matrix,the results of recovery were found to be 97.4% for vitamin B6,100.3% for calcium pentothenate and 102.4% for nicotinamide.