Determination of Salt in Miso and Soysauce by Argentometry

Abstract

Potentiometric titration with silver nitrate was applied to the determination of chloride in miso and soysauce. The titration with this method conducted on the dilute sample dispersions containing ca 0.35% nitric acid and 0.05% Tween 20 gave results in satisfactory precision and the relative error was 0.1-0.2%, while, Mohr's method constantly gave higher values on the same samples due to titration in excess, and its relative error fluctuated 2.6-6.1% on miso and 1.0-3.6% on soysauce. The loss of chlorine during ignition of miso ranged in 0.5-4.5% and such loss was greater in the samples made from higher ratio of rice. The average loss determined on soysauce was 1.2%.