离子交换树脂-固相萃取富集-电感耦合等离子体光谱法测定水中重金属元素

建立了离子交换树脂-固相萃取富集-电感耦合等离子体光谱(ICP-AES)联用测定水中的重金属元素Zn，Mn，Cu，Co，Ni，Cd，Pb的方法。实验采用Dowex50WX8强酸型阳离子交换树脂，通过优化富集分离条件和排除共存离子的干扰，最终确定最佳的样品pH，样品流速，洗脱液种类和浓度，样品体积分别为3.0~4.0，3.0 mL·min-1，3.0 mol·L-1 HNO₃，200 mL。方法中各元素的检出限和定量限范围分别为0.09~0.45和0.31~1.50 μg·L-1，加标回收率和相对标准偏差RSD(n=6)分别为95.3%～104.2%和1.25%～4.12%。采用该方法测定不同地区的样品，并与直接采用ICP-MS法进行对比，其测定结果基本吻合。实验表明该方法的检出限，定量限可以满足水中重金属元素Zn，Mn，Cu，Co，Ni，Cd，Pb的检测要求，准确性和精密度好，结果可靠，适用于测定水中Zn，Mn，Cu，Co，Ni，Cd，Pb。

Preconcentration and Determination of Heavy Metals in Water Samples by Ion Exchange Resin Solid Phase Extraction with Inductively Coupled Plasma Atomic Emission Spectrometry

This paper established the method for preconcentration and determination of heavy metals such as Zn, Cu, Co, Mn, Ni Cd, Pb in water samples by solid phase extraction (SPE) with inductively coupled plasma atomic emission spectrometry(ICP-AES). In this experiment, Dowex 50WX8 strong acid cation exchange resin was used and by optimizing the conditions of preconcentration and eliminating the interference of coexisting ions, the optimum sample pH, sample flow rate, eluent type and concentration, sample volumes were determined with 3.0~4.0, 3.0 mL·min-1, 3.0 mol·L-1 HNO₃ and 200 mL, respectively. For this method, the detection limit and quantitation limit of each element were 0.09～0.45 and 0.31～1.50 μg·L-1, respectively. The recoveries and relative standard deviations RSD (n=6) were 95.3%～104.2% and 1.25%～4.12%. The water samples of different parts were determined by this method and compared with the direct determination by ICP-MS, the results of the both methods were basically identical. All of these indicated that the detection limit and quantitative limit in this method could meet the requirements for determination of heavy metals in water samples. The accuracy and precision of the method were high which were suitable for the determination of Zn, Mn, Cu, Co, Ni, Cd, Pb in water samples.