【摘要】 本文提出了络合极谱双点滴定中置换滴定法的测定方法和定量公式。研究了以ＥＤＴＡ为络合剂，在ＨＡｃ－ＮａＡｃ缓冲溶液中，以乳酸置换与Ｓｎ￣（４＋）络合的ＥＤ－ＴＡ，以ＣｄＣｌ＿２标准溶液为滴定剂测定Ｓｎ。对于５×１０￣（－５）ｍｏｌ的Ｓｎ，回收申达９９．２％。应用该法于青铜样品中Ｓｎ的含量的测定，结果较为满意。更多还原

【Abstract】 A new method of polarographic double-point titration through displacement and com-plexation reactions was established. Thereagent CdCl₂ was used as titrant to determinethe EDTA in excess and that in Sn-EDTA.Lactic acid was used as the displacementreagent for EDTA in Sn-EDTA.The recoverywas 99.2%for 5×10￣（-5）mol Sn.The methodwas applied to the determination of Sn inbronze with satisfactory results更多还原