The Evaluation of Ethyl Eosin

Suitable methods for the determination of eosin and ethyl eosin in samples of the latter dye are described. They depend upon the possibility of precipitating the color acid and measuring the same gravimetrically. What proportion of the dye is actually ethyl eosin and what proportion is eosin Y can be determined by making use of the great difference in solubility of the two dyes in water.