Purification Of Folic Acid Candidate Reference Material By Preparative High-Performance Liquid Chromatography

An effective process for the purification of folic acid candidate reference material with preparative high-performance liquid chromatography (Pre-HPLC) was developed in this study. During the process of experimental operation, parameters including the influences of mobile phase, flow rate, and injection volume on the purity and yield were investigated, and the optimized conditions were as follows: the mobile phase was acetonitrile and water in a gradient mode with flow rate of 16mL/min and injection volume of 2.0mL at concentration of 10mg/mL. Under the conditions, the purity and yield of folic acid product were up to 99.4% and 21.0%, respectively, whereas the purity of folic acid raw material was 95.2%. The purified folic acid product was characterized by LC-MS, HPLC, Karl Fischer coulometer, and quantitative nuclear magnetic resonance (qNMR). Results proved that the main component of the product was folic acid and the purities determined by HPLC and qNMR were consistent. Two impurities including N-(4-aminobenzoyl)-L-glutamic acid and pteroic acid were further quantified by LC-MS. Compared with the recrystallization approach, the purity of folic acid obtained by Pre-HPLC increased from 98.2% to 99.4%.[GRAPHICS]