三钛酸钠晶须预富集/分离与FAAS法联用测定环境水中镉的研究

三钛酸钠晶须是一种新型的富集材料，实验利用火焰原子吸收光谱(FAAS)法，探讨了三钛酸钠晶须对Cd(Ⅱ)的吸附行为及影响其吸附和解脱的主要因素及共存离子的影响，考察了三钛酸钠晶须对Cd(Ⅱ)的吸附容量。当pH 5，吸附剂用量0.05 g时，吸附率可达98%。以0.1 mol·L-1的盐酸为解脱剂，沸水浴加热30 min，可将吸附在三钛酸钠晶须上的Cd定量洗脱。方法检出限为3.1 ng·L-1,相对标准偏差为2.6%(Cd(Ⅱ): 0.2 μg·mL-1,n=9)。实验结果表明Cd(Ⅱ)在0.01～1.0 μg·mL-1之间线性良好。线性回归方程为A=0.4179c-0.004 8，相关系数r=0.999 67。在优化的实验条件下，实测了长江水，运河水，玉带河水中Cd的含量，加标回收率为98%～102%。

Flame Atomic Absorption Spectrometry Determination of Cadmium in Environmental Water with Preconcentration and Separation by Sodium Trititanate Whisker

Sodium tertitanate whisker is a new material for preconcentration. The adsorption properties of sodium trititanate whisker for Cd(Ⅱ) were studied and a new method for preconcentration and separation of Cd(Ⅱ) was proposed. The adsorption rate of Cd(Ⅱ) by sodium trititanate whisker was 98% at pH 5.0 and Cd(Ⅱ) could be eluted from sodium trititanate whisker with hydrochloric acid (C: 0.1 mol·L-1). The Cd(Ⅱ) in environmental water was preconcentrated with sodium trititanate whisker and determined by flame atomic absorption spectrometry (FAAS). The detection limit (3σ, n=9) was 3.1 ng·L-1,and the relative standard deviation (RSD) was 2.6%. The response of proposed method is linear in the concentration range of 0.01-1.0 μg·mL-1 of Cd(Ⅱ). The method was applied to the determination of analytes in real samples, such as Changjiang River water, Canal water, Yudai River water etc. Good results were obtained (relative standard deviations were 1.5%-4.7%, while recoveries were 98%-102.0%).