摘要
基于Ｍｏ（Ⅵ）和Ｗ（Ⅵ）与新显色剂４－（６－溴－２－苯并噻唑偶氮）邻苯二酚（６－Ｂｒ－ＢＴＡＰＣ）和二苯胍（ＤＰＧ）在ｐＨ４．０时形成稳定的１∶２∶２电中性紫红色三元离子缔合物的灵敏显色反应，用三波长法同时萃取分光光度法测定了体系中共存的钼和钨。两配合物氯仿萃取液的λｍａｘ分别为５５９和５３９ｎｍ，表观摩尔吸光系数分别为８．６３×１０４和６．５３×１０４Ｌ·ｍｏｌ－１·ｃｍ－１，比耳定律的适用范围分别为０～０．８ｍｇ／Ｌ和０～１．８ｍｇ／Ｌ，最佳三波长组合分别为５１５．０、５７５．０、６３２．３ｎｍ和５３５．０、５９５．０、６７１．１ｎｍ。按最佳实验条件对模拟试样及合金钢样中小量或痕量的钼和钨进行了同时测定，取得了满意的结果。
o(Ⅵ) and W(Ⅵ) react with 4(6bromo2benzothiazolylazo) pyrocatechol (6BrBTAPC) ,a new chromogenic reagent,and diphenyl guanidine (DPG) to form two stable violetred neutral 1∶2∶2 ternary ionic associate complexes at pH4.0.Based on this sensitive chromogenic reaction,coexisting Mo(Ⅵ) and W(Ⅵ) in the systems were simultaneously determined by using extractionspectrophotometry combined with three wavelength method.The optimum combinations of three wavelengths are 515.0,575.0,632.3nm and 535.0,595.0,671.1nm,respectively ,with respective λmax of 559 and 539nm,and respective apparent molar absorptivities of 8.63×104 and 6.53×104L·mol-1·cm-1 for the chloroform extracts of the ternary ion associate complexes.Beer's law is obeyed in the ranges of 0 to 0.8mg of Mo(Ⅵ) and 0 to 1.8mg of W(Ⅵ) per liter.Satisfactory results have been achieved in applying the method to determination of trace or minor molybdenum and tungsten in simulated samples and alloy steel samples.
出处
《分析试验室》
CAS
CSCD
1998年第4期1-4,共4页
Chinese Journal of Analysis Laboratory
基金
化工部科学基金
关键词
钼
钨
Br-BTAPC
分光光度法
测定
Molybdenum
tungsten
4(6bromo2benzothiazolylazo) pyrocatechol
diphenyl guanidine
spectrophotometry
three wavelength method
alloy steel
