在pH 3.0～4.5范围,水相中缔合物(EV)_2[BiI_5](λ_(max)=540nm)同试剂(λ_(max)=650nm)有较大的对比度。在完成缔合后的体系中加入适量酸,过量乙基紫阳离子质子化使对比度、灵敏度增高。用于微量铋的测定,0～24μg/25ml范围符合比尔定律,表观摩尔吸光系数为2.05×10~5。用于样品分析结果满意。 In the pH range of 3.0 ~ 4.5, there is a large contrast in the aqueous phase (EV) _2 [BiI_5] (λ max = 540 nm) with the reagent (λ max = 650 nm). After the completion of the association system by adding the right amount of acid, excessive ethyl violet cation protonation so that the contrast, increased sensitivity. For the determination of trace bismuth, 0 ~ 24μg / 25ml range in line with Beer’s law, the apparent molar absorptivity of 2.05 × 10 ~ Satisfactory results for sample analysis.