薄层树脂相分光光度法测定水中痕量铋  

Thin layer resin phase spectrophotometric determination of trace bismuthⅢ in water sample

作　　者：赵干卿[1] 闫永胜[1] 谢吉民[1] 

机构地区：[1]江苏大学化学化工学院

出　　处：《冶金分析》2006年第4期53-55,共3页Metallurgical Analysis

基　　金：江苏大学高级人才基金项目(04JDG017);江苏省博士后科研资助项目(050219B)

摘　　要：在酸性条件下，I^-与Bi（Ⅲ）形成络合阴离子[BiI4]^-，该络合阴离子易与Cl^-型717阴离子交换树脂中的Cl^-进行等离子对交换缔合，形成离子对缔合体系（R^＋（阴离子交换树脂）-[BiI4]^-），该缔合体系在460nm处有最大吸收，ε=7．1×10^5L·mol^-1·cm^-1，据此建立了薄层树脂相分光光度法测定痕量铋的新方法。方法灵敏度高，是水相光度法18倍，测定0．5μg／mL Bi（Ⅲ）6次，RSD=1．82％，方法线性范围为0～1．2μg／mL，检出限为1．4×10^-8mol／L。实测了天然水样中Bi（Ⅲ），加标回收率为96％～103％，与原子吸收光谱法测定值相比较，结果吻合。A new method for the determination of Bi（Ⅲ） in water sample by thin layer resin phase spectrophotometry was developed. Bi（Ⅲ） with I^- forms a complex anion of [BiI4 ]^- , which can exchanges and associates with Cl^- on the surface active sites of anion exchange resin （R^＋ ） of 717 type to form an association system of （R^＋） - [BiI4 ]^-. The maximum absorption wavelength of the system was located at 460 nm. The thin layer resin phase spectrophotometry gives a apparent molar absorptivity of （ε460） 7. 1 × 10^5 L· mol^- 1· cm^- 1, which is about 18 times higher than in water phase（ ε460 = 3.9 × 10^4 L· mol^- 1·cm^- 1 ）. It had an ideal precision （0.5 μg/mL Bi（Ⅲ）, n = 6, RSD = 1.82% ）. The detection limit of Bi（Ⅲ） in aqueous solution is 1.4 × 10^-8mol/L, and Beer＇s law is obeyed in the range of 0- 1.2 μg/mL for Bi（Ⅲ）. Bi（Ⅲ） was determined in natural water with recovery of 96% - 103%, and the determination results are agreement with those of atomic absorption spectrometry.

关 键 词：薄层树脂相分光光度法 铋 测定 水样 

分 类 号：O657.3[理学—分析化学]