【摘要】 <正> 光度测定砷的方法常用的有:砷钼蓝法、砷钼黄法、二乙基二硫代氨基甲酸银法(AgDDTC法)等。这些方法多需采取加热还原、有机溶剂萃取等步骤,操作复杂,灵敏度低,ε一般在10~4左右。近年来所研究的一些借助有机溶剂萃取碱性染料-络阴离子缔合物的方法,灵敏度很高,ε普遍大于10~5,满足了某些痕量元素测定的需要。曾先用乙醚浮选分离砷钼杂多酸-罗丹明B缔合物,然后再在乙醚-丙酮溶液中加以测定;继而,他又用环己酮-甲苯混合溶剂选择性萃取结晶紫-砷钼杂多酸的方法光度测砷,ε达3.2×10~5。但方法繁杂,操作条件严苛,重现性差,在实际工作中较难更多还原

【Abstract】 A highly sensitive spectrophotometric method for the determination of arsenic was devoloped. In the presence of nonionic surfactants, the optimal conditions for the quantitative formation of the ion-association complex of molybdoarsenic acid with crystal violet,（CV）₃(AsMo₁₂O₄₀,were described. The calibration curve is linear with in the range of 0～15.0 μgAs/25 ml, and the molar absorptivity is 1.70×10⁵ 1·mol^-1·cm^-1, the molar ratio of CV:(AsMo₁₂O₄₀)=3:1. The proposed procedure was applied to the simultaneous determination of traces of arsenic and phosphorus in steel and hair. The results were satisfactory.更多还原