Abstract
Barium rhodizonate liberates rhodizonic acid when reacts with sulfate ion in aquous solution. The sulfates contents of bittern, sea brine and common salts were determined by measuring the absorbancy of thus liberated rhodizonic acid. The measurments were made at 530mμ, adding iso-propylalcohol or ethyl-cellosolve as color stabilizer, in pH range 4-7. Good results were obtained for each sample, and Ca++, Mg++ or Al+++ did not interfer.
