STUDY ON IODOMETRIC DETERMINATION OF H_2O_2 MASS FRACTION IN PROPYLENE EPOXIDE

The orthogonal design was employed to research the optimized titration conditions for a simulated solution of propylene epoxides. It is concluded that the amount of sample gave the most significant influence to the titration result, while the amounts of both KI and H_2SO_4 solutions only provided significant influences. The mass fraction(x) of H_2O_2 measured by titration in propylene epoxide solution was well consistent with its true value if x was in the range of 0.5%-3.3%, and the minimal amount (m) of the solution being titrated was estimated by m=0.17/x and the amounts of KI and H_2SO_4 solutions used in titration were between (3-8 ml) and 2-7 ml respectively. It is shown that titration results of the solution with different H_2O_2 contents were always well consistent with their true value under these conditions. The maximum amounts of KI and H_2SO_4 solutions used in titration were not more than 8 ml and 7 ml respectively at the relative low mass fraction (0.5%) of H_2O_2 in propylene epoxide solution, and the minimum amounts of them are not less than 3 ml and 2 ml respectively at the relative high mass fraction (3.3%) of H_2O_2, which is then verified by further experiments.