Polarographic determination of folic acid in pharmaceutical preparations

Abstract

A.c. polarograms of folie acid recorded from acetate buffer pH 5.5 exhibit a very welldefined wave at the dropping mercury electrode. The current is diffusion-controlled and proportional to the concentration; the optimal range of measurement is 0-24̄ μg ml -1. Two electrons and two hydrogen ions are involved in the reduction. With the phase-sensitive a.c. polarographic method, the calibration graph is linear in the 2 × 10 -8—2 × 10 -6 M range. The method proposed for the determination of folic acid in tablets is very simple and rapid, and does not involve time-consuming separation of iron salts and insoluble constituents in the tablets.