Abstract An improved method was developed for preparation of 5, 6, 7, 8-tetrahydrofolic acid (THF) and calcium-5-methyltetrahydrofolate (5-MTHF-Ca) by reduction of folic acid using KBH 4 catalyzed by Pb (NO 3) 2. The yields of THF and 5-MTHF-Ca were 56.5 and 42.7%, respectively. A convenient method for measurement of THF and 5-MTHF-Ca using liquid chromatography–mass spectrometry (LC–MS) was also established, enabling analysis of ...
