混合金属离子络合滴定条件的讨论

混合金属离子络合滴定条件的讨论 DISCUSSIONS ON COMPLEXOMETRIC TITRATION OF MIXED METAL IONS 王志铿 Wang Zhikeng and Zhao Zaofan first-author 赵藻藩 本文进一步对混合金属离子络合滴定的条件进行讨论,并用实验证明:国内长期流行的根据log C N K′ NY ≤1来判断最低允许酸度的理论是不正确的。只要指示终点方法选择适当,当log C N K′ NY ≥1时,N离子并不干扰M离子的滴定。 In this paper, Complexometric titration of mixed metal-ions has discussed theoritically and proved by experiments that theory of so Called "lowest allowable acidity" Calculated from log C N K’ NY ≤1 which was very popular in our country is incorrect. In dilute ammonia solution pH≈10 by using of chrome azurol S（CAS） and Eriochrome black T（EBT） as indicator, or by potentiometric titration by using of Cu-selective electrode as indicator eleetrode, Cu 2+ and Mg 2+ can be titrated successively without being interfered each other. But they are considered imposible to be titrated according to theory of logC N K’ NY ≤1. 1982-03-01 2021-04-01 3