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本刊1983第4期17页介绍了用氨水溶解洗脱附有AgCl沉淀的吸管。此法虽然可行,但氨水臭味大,对鼻、眼粘膜有很大刺激性。我们对管壁附着有氯化银沉淀的吸管,用5%硫代硫酸钠溶液数滴,沿管内流过,沉淀即可溶解,再以常水、蒸馏水依次冲洗即可洗净。就络合物稳定性而言,pK_[(?)=7.1,而Ag~+与S_2O~(2-)_3络合时此常数可达13.46～14.15(武汉大学等:分析化学,561页,人民教育出版社,1979),较前者高6～7个数量级,且硫代硫酸钠无臭无毒,溶解度大,与氨水相比,同样价廉易得。因此,洗脱氯化银沉淀宜用硫代硫酸钠。
This issue 1983, No. 4, page 17 describes the use of ammonia dissolved eluted with AgCl precipitation pipette. Although this method is feasible, but ammonia odor, on the nose, eye mucosa is very irritating. We attached to the pipe wall of silver chloride precipitation pipette, with 5% sodium thiosulfate solution a few drops along the tube, the precipitate can be dissolved, and then to normal water, distilled water followed by rinse to wash. For the stability of the complex, pK _ [(?) = 7.1, while the constant of Ag ~ + and S_2O ~ (2 -) _3 can reach 13.46 ~ 14.15 (Wuhan University et al .: Analytical Chemistry, People’s Education Press, 1979), higher than the former 6 to 7 orders of magnitude, and sodium thiosulfate odorless, high solubility, compared with ammonia, the same cheap easy to get. Therefore, elution of silver chloride precipitation should use sodium thiosulfate.