汞(Ⅱ)的三元离子缔合物浮选及其应用于光度法测定水中痕量汞(Ⅱ)  

Solvent Fioatation of Mercury(Ⅱ) as a Ternary Association Complex and Its Application to Photometric Determination of Traces of Mercury(Ⅱ) in Water

作　　者：程永华[1] 吕鹏飞[1] 陈婷玉[1] 李春香[1] 闫永胜[1] 

机构地区：[1]江苏大学化学与化工学院

出　　处：《理化检验（化学分册）》2008年第7期655-657,共3页Physical Testing and Chemical Analysis(Part B:Chemical Analysis)

基　　金：科技部创新基金项目(03C26213200932);江苏大学高级人才基金(04JDG017)

摘　　要：在pH 6.5的微酸性溶液中,汞(Ⅱ)与碘离子形成的络阴离子HgI_2^(2-)和亚甲基蓝的阳离子MB^+生成离子缔合络合物;在分液漏斗中与一定量的苯振摇后,该缔合物[HgI_4^(2-)]·2[MB^+]以第三相的形态在水相与苯相之间浮选析出。将水相及有机相弃去,用丙酮将析出的浮选相溶解后在657 nm波长处测定其吸光度。汞(Ⅱ)量在12.0～22.0 mg/25 mL内服从比耳定律,摩尔吸光率为3.5×10~5L·mol^(-1)·cm^(-1),方法的检出限为5.1×10^(-7) mol·L^(-1)。对12.0μg/25 mL汞(Ⅱ)标准按方法连续测定11次,算得测定结果的相对标准偏差为3.98%。应用所提出的方法以合成水样为基体,加入汞(Ⅱ)标准溶液进行回收试验,测得回收率在94.8%～100.1%之间。An association complex was formed between the anionic complex HgI4^2- and methylene blue MB^＋ in a slightly acidic solution of pH 6.5, and floated by shaking with benzene. The association complex [HgI4^2- ] · 2[MB^＋ ] was separated out in a separatory funnel as the 3rd phase between the water phase and benzene phase, and after discarding the water and organic phases, it was dissolved in a definite volume of acetone, and its absorhance was measured at the absorption maximum of 657 nm. Beer＇s law was kept in the range of 12.0-22.0 mg of Hg（ Ⅱ） in 25 mL of test solution. Molar absorptivity （ε6s7） was found to be 3. 5× 10^5L · mol^-1 · cm^-1. Detection limit of the method was 5.1 × 10^-7mol · L^-1. Precision was tested at the concentration level of 12. 0 μg Hg（Ⅱ ） per 25 mL solution for 11 determinations, giving value of RSD＇s of 3. 98% Test for recovery was performed by addition of standard Hg（ Ⅱ） solutions to 3 simulated water samples, and values of recovery obtained were in the range of 94. 8G to 100. 1G.

关 键 词：光度法 浮选法 离子缔合物 汞(Ⅱ) 水 

分 类 号：O657.31[理学—分析化学]