在阴离子表面活性剂存在下3,5-diCl-DMPAP分光光度法测定微量锌

Spectrophotometric determination of trace amounts of Zinc(Ⅱ) with 3,4 diCl DMPAP in presence of anionic surfactant

在阴离子表面活性剂ＳＬＳ存在下，研究了２－（３，５－二氯－２－吡啶偶氮）－５－二甲氨基酚（简称３，５－ｄｉＣｌ－ＤＭＰＡＰ）与锌反应的适宜显色条件．结果表明，在ｐＨ为６．０～１０．０范围内，锌（Ⅱ）与试剂形成１∶２的紫红色配合物．配合物的最大吸收波长位于５６５ｎｍ处，表观摩尔吸光系数为１．２×１０５Ｌ·ｍｏｌ－１·ｃｍ－１，锌浓度在０～６．０μｇ／１０ｍＬ范围内遵守比尔定律．

The conditions related with the formation of Zinc(Ⅱ) complex with 2 (3,5 dichloro 2 pyridylazo) 5 dimethylaminophenol(3,5 diCl DMPAP) in the presence of anionic surfactant SLS has been investigated. The results show that Zinc(Ⅱ) formes a purlish red complex(1∶2) with 3,5 diCl DMPAP in the pH range of 6 to 10. Its maximum absorption is at 565nm. The apparent molor absorption coefficient is 1.2×10 5 L·mol -1 ·cm -1 . Beer′s law is obeyed in the range of 0 to 6.0 μg Zn/10 mL. This method has been used for the rapid determination of the trace amounts of Zinc in geological sample and magnesium alloy wiht satisfactory results.