选择性螯合滴定法测定钛钼合金中的钛

SELECTIVE CHELATOMETRY TITRATION TITANIUM IN TITANIUM-MOLYBDENUM ALLOYS

用磷酸三钠作释放剂，选择性螯合滴定济测定钛。在样品溶液中，加入过量的EDTA（螯合Ti4＋和其它金属离子），剩余的EDTA在pH5～6时，用锌标准溶液进行返滴定，以XO－CTMAB为混合指示剂，终点变化额外敏锐。用磷酸三钠为释放剂，分解TiEDTA螯合物，释放出的EDTA再用锌标准溶液进行滴定。曾对多种阳离子可能存在的干扰做了研究。一般金属离子均不干扰。此法已用于测定钛钼合金、钛基合金中的钛。

A method is proposed for selective chelatometry titration of titanium therein trisodium phosphatebeing used as releasing agents, An excess of EDTA (chelate of Ti4+ and other metal ions)is added to tbe sample solution and the surplus EDTA is back-titratedat pH 5~6 with zinc standard solution,while the xylenol orange (XO)-cetyltrimethy lammonium,bromide (CTMAB) being used as mixed indicator,the end point change is more sensitive. Trisodium phosphate is then added to decompose the Ti-EDTA chelates and the liberated EDTA is againtitrated with zinc standard solution. The possible interference of various cations has been studied..Metal ions in general have no interference. The method has been used for the determination of titanium in titaniummolybdenum alloys and titanium base alloys.