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关于铜合金中锡的络合滴定,已有人提出过.成都无线电厂及贵州省科委计量中心试验室提出:在PH=2～2.5时,用二甲酚橙作指示剂,用硝酸铋或硝酸钍反滴定.此时除Cu~(+2)、Fe~(+3)、Bi~(+3)及大量Ni~(+2)外,其余元素均不干扰.虽然铜可以用硫脲掩蔽,铁的干扰用抗坏血酸消除,但镍和铋的干扰无法消除. 武汉汽车配件厂提出的另一方案是当PH≥1时,使锡与过量的EDTA络合,然后调整PH=5.5～6,
On the complexation of tin in copper alloy titration, has been proposed.Chengdu radio factory and Guizhou Science and Technology Commission measurement center laboratory proposed: PH = 2 ~ 2.5, with xylenol orange as an indicator, with bismuth nitrate or In addition, all the other elements except Cu ~ (+2), Fe ~ (+3), Bi ~ (+3) and a large amount of Ni ~ (+2) Masking, iron interference with ascorbate to eliminate, but the interference of nickel and bismuth can not be eliminated.Wuhan Auto Parts Factory proposed another solution is when PH ≥ 1, the tin and excess EDTA complexation, and then adjust the PH = 5.5 ~ 6 ,