PAN流动注射分光光度法测定水样中的镍(Ⅱ)

Determination of Trace Nickel(Ⅱ) in Water Samples by Flow-injection Spectrophotometric Analysis Using PAN

在pH8．0的NHa-NH4C1缓冲溶液中，在非离子表面活性剂吐温80存在下，Ni^2＋与1-（2-吡啶偶氮）-2-萘酚（PAN）生成红色络合物，据此建立了流动注射分光光度法测定水样中痕量镍（Ⅱ）的分析方法。测定结果表明本方法的灵敏度、准确度都较高，且流路简单，操作方便，抗干扰较好。测定河口湖泊水时，在0．1～1200μg／L浓度范围内具有良好的线性关系，0．1～2μg／L浓度范围内相关系数为0．9998，2～100μg／L浓度范围内相关系数为0．9994，100-1200μg／L浓度范围内相关系数为0．9995，检出限为0．05μg／L，回收率为98．2％～105．9％，用40μg／L标准溶液进样的相对标准偏差为1．47％（n=11）。加入掩蔽剂后该方法用于实际水样分析，结果让人满意。

A red complex of nickel（ Ⅱ ） was formed when nickel（Ⅱ） reacted with 1-（2-pyridylazo）- 2-naphtol（PAN） in the medium of NH3-NH4 Cl（pH8. 0） buffer solution containing Tween-80. Combining flow injection technology, a flow injection chemiluminescence method was established for quantitative analysis of trace nickel（ Ⅱ ） in water samples. The results showed the method was sensitive, precise and simple, quick and anti-interference. The linear range was 0. 1-1200 μg/I, for nickel（Ⅱ） when the water of the river and the lake was determined, and the relative coefficient was 0. 9998 for 0. 1-2 μg/L, 0. 9994 for 2-100 μg/L, 0. 9995 for 100-1200 μg/L, the detection limit was 0. 05 μg/L, the recovery rates were 98. 2%-105.9%, the RSD of 40 μg/L nickel（ Ⅱ ） standard solution was 1.47%（n=11）. The trace nickel（ Ⅱ ） can be determined directly in water samples by adding masking agents and the results are satisfactory.