一种新的测定锶的高选择性光度法的研究——用新显色剂 DBC-偶氮氯膦测定合金及海水中的锶

Studies on Determination of Strontium by a New Highly Selective Spectrophotometry——Determination of Strontium in Alloy and Sea Water with Chlorophosphonazo-DBC

锶的分析在环保、医学、地质和工业上都有重要的意义.目前,锶的测定缺乏简单可行的光度分析法.有人曾讨论过测定碱土元素的光度法所用的有机试剂.文献还报道过一些测锶的方法,但这些方法选择性不够完善,没有很好解决钙、钡共存的干扰,往往需要进行分离后才能测定.

In acidic solution,a stable purple colour complex of strontium was formed with anew photometric reagent,2-(4’-chloro-2’-phosphonazo)-7-(2’,6’-dibromo-4’-chloro-phenylazo)-1,8-dihydroxy-3,6-naphthalene disulfonic acid(DBC-CPA).This complexexhibits absorption maximum at 630nm with apparent molar absorptivity of6.3×10~4 L·mol-1·cm-1.The molar ratios of this complex is found to be Sr:DBC-CPA=1:2.In the presence of acetone,Na2SO4 and EDTA and the absorbance determined bythe dual-wavelength,there is no interference by the presence of large amounts ofbarium,calcium,iron,magnesium and a number of other ions.A method has beendeveloped for the determination of strontium in sea water,magnesium oxide,silicon-iron alloy with satisfactory results.