碘量法测定丙烯环氧化产物中双氧水质量分数的研究

模拟H2O2氧化丙烯的环氧化产物，利用正交实验方法得到了测定H2O2质量分数的最佳滴定条件。结果表明，滴定时被测样品质量对测定结果的影响很显著，KI和H2SO4。溶液的加入量的影响显著。当被测丙烯环氧化产物中H2O2的质量分数为0．5％～3．3％时，其最小的滴定样品质量，w由式m=0．170。（x代表被测环氧化产物中H2O2的质量分数）估计，且在滴定过程中KI和H2SO4溶液的加入量分别在3～8ml和2～7ml范围时，测定结果与真实值相吻合。在丙烯环氧化产物中H2O2质量分数相对较低（〈0．5％）时，应控制KI和H2SO4溶液的加入量不能超过8ml和7ml，而在H2O2质量分数相对较高（〉3．3％）时．应控制KI和H2SO4溶液的加入量不能低于3ml和2ml。该规律在后来的实验中得到了验证。

STUDY ON IODOMETRIC DETERMINATION OF H2O2 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.