【摘要】 在H3PO4介质中,Pb(Ⅱ)-碘化钾-罗丹明6G形成红色的三元离子缔合物,缔合物的组成比为:Rh6G∶Pb(Ⅱ)∶I-=2∶1∶4,聚乙烯醇的存在可增敏该体系,摩尔吸光系数为3.64×105L.mol-1.cm-1,铅(Ⅱ)的浓度在0.01~0.4 mg.L-1范围内服从比尔定律.研究了试剂用量、温度、干扰物等因素的影响,结合巯基棉吸附,测定了4种环境水样及鸡精、猪肝、油麦菜等样品中的痕量铅.更多还原

【Abstract】 A highly sensitive spectrophotometric method has been developed for the determination of trace Pb(Ⅱ),which based on the formation of a complicated ion-association complex of Pb(Ⅱ) with rhodamine 6G and polyvinyl alcohol in the phosphate acid.The composing ratio of the complex is Rh6G∶Pb(II)∶I-= 2∶1∶4,the addition of PVA can enhance the sensitivity of the reaction and its apparent molar absorptivity is 3.64×105 L· mol-1 · cm-1.Beer’s law is obeyed in the range of 0.01～0.4 μg · mL-1 for Pb(Ⅱ).The effects of the reagents’ concentration,the temperature and the influence of foreign matters have been studied.Combined with the sample preparation with sulfhydryl cotton,the proposed method has been used for the determination of trace Pb(Ⅱ) in 4 water samples and 3 food samples.更多还原