Application of differential pulse polarography to the assay of vitamins

Abstract

The determination of low concentrations of the vitamins B₂, nicotinic acid, nicotinamide, ascorbic acid, K₁ and K₃ in pure solutions by use of differential pulse polarography has been studied. The approximate limits of detection achieved for the different vitamins varied from 0·01 to 1 p.p.m., which is 10 to 100 times better than for d.c. polarography. A comparative determination of vitamin B₂ and nicotinamide in three complex multivitamin preparations showed that differential pulse polarography is more selective than d.c. polarography. With the former method the nicotinamide can be determined directly, i.e., without prior separation of interfering substances.