Analysis of peracetic acid solutions

In the estimation of peracetic acid in aqueous solution, hydrolysis of the peroxy group must be taken into account. The best volumetric method is an indirect one using cerium(IV) as the oxidant, followed by iodometric titration of the excess of cerium(IV). A spectrophotometric estimation of the hydrogen peroxide present, based on the peroxytitanium(IV) complex is satisfactory if measurements are made at known time intervals and extrapolated to zero time.