应用聚丙烯酸钠为结合相的薄膜扩散梯度技术测定水中Cd²⁺

来源期刊：冶金分析2011年第2期

论文作者：陈宏 邸万山 赵晋 董佳 孙挺

文章页码：15 - 19

关键词：聚丙烯酸钠； 薄膜扩散梯度； 结合相； 镉； 火焰原子吸收光谱法； 离子选择性电极

Key words：sodium polyacrylate； diffusive gradients in thin-films； binding phase； cadmium； flame a-tomic absorption spectrometry； ion selective electrode

摘    要：研究了以聚丙烯酸钠(PAAS)溶液为结合相的薄膜扩散梯度(DGT)装置(PAASDGT装置)用于测定水中Cd²⁺的分析方法。考察了DGT技术的有效性、PAAS DGT装置饱和累积容量以及本体溶液pH值、离子强度对PAAS DGT装置累积Cd²⁺的影响。实验表明:PAAS DGT装置的饱和累积容量为278.88 mg/L,本体溶液pH值在4~10和离子强度在0.000 1~0.1 mol/L范围内基本不影响PAAS DGT对Cd²⁺的累积,以PAAS为结合相的DGT装置对合成水中Cd²⁺的累积量与时间呈线性关系,线性相关系数r为0.999 6,回收率为99.25%,RSD%为1.96%。PAAS DGT装置与火焰原子吸收光谱法相结合可用于水样中Cd²⁺的测定,测量结果与镉的离子选择电极法(Cd-ISE)相符,并具有比Cd-ISE更低的检出浓度。

Abstract: The free cadmium ion in water was measured by using sodium polyacrylate (PAAS) as bind-ing phase in the diffusive gradients in thin-films (DGT) device (PAAS DGT device).Multiple prob-lems were discussed,such as the effect of DGT,the saturated cumulative capacity of PAAS DGT de-vice,the pH value of bulk solution and the effect of ion intensity on the cumulation of Cd²⁺ in PAAS DGT device.The saturated cumulative capacity of PAAS DGT device were 278.88 mg/mL.The cu-mulation capacity of PAAS DGT device for Cd²⁺ was not affected when the bulk solution was at pH 4-10 and ion intensity was from 0.000 1 mol/L to 0.1 mol/L.The linear correlation coefficient(r) of cumulated mass of Cd²⁺ in synthetic water with time was 0.999 6 with the recovery of 99.25% and the relative standard deviation (RSD) of 1.96%.It was proved that PAAS DGT device could be ap-plied to the determination of free Cd²⁺ ion in combination with flame atomic absorption spectrometry.The results were consistent with those by Cd ion selective electrode(Cd-ISE),and the detection con-centration was even lower.