An autoanalyzer method for determining hexachlorophene in soap

Abstract

An AutoAnalyzer method has been developed for determining hexachlorophene in soap. The free phenol group is condensed with 4‐amino‐antipyrine, and after oxidizing with alkaline potassium ferricyanide, the resulting quinonetype dye is colorimetrically measured at 480 mƁ. Internal standards are employed having known amounts of hexachlorophene. The method is applicable to the range that would be expected in a germicide soap, i.e. from 0‐2%. The overall precision was found to be ŷ0.022% (95% confidence limits) at the 1.00% level of hexachlorophene in soap. The presence of other germicide types such as for example, carbanilides or salicylanilides, should not interfere with the determination. This routinized method should prove useful in operations where numerous repetitive measurements are made.