聚乙烯毗咯烷酮修饰碳糊电极溶出伏安法测定水中硝基酚

提出用聚乙烯毗咯烷酮（ＰＶＰｒ）修饰碳糊电极同时测定水中对硝基酸和２，４－二硝基酚的方法。在０．１ｍｏｌ／ＬＫＣｌ的酚试液中开路富集，然后在磷酸盐缓冲液介质中溶出．以微分脉冲伏安法恻定，检测限分别为０．５０μｇ／Ｌ和１．８０μｇ／Ｌ。讨论了测定的影响因素以及２种硝基酚在该修饰电极上的反应机理。测定了地面水中对硝基酸和２，４－二硝基酸的含量，回收率分别为９０±６％和８６±５％。

Determination of Trace Levels of Nitrophenols in Water by Polyvinylpyrrolidone Modified Carbon Paste Electrode

In this paper, a method to determine simultaneously p-ni-trophenol and 2,4-dinitrophenol in water by differential pulse voltammetry (DPV) with a carbon paste electrode modified with 10% (W/W) polyvinylpyrrolidone (PVPr) was described. The electrode showed a strong response to the nitrophenols, and the sensitivity and selectivity were much higher than ordinary carbon paste electrode. The nitrophenols were preconcentrated in 0.1 mg/L KCI solution during open circuit period, then the preconcentrated nitrophenols at the electrode were determined in phosphate buffer solution (pH7.0). The oxidation peak potentials were+0.88 V and+1.23 V (VS Ag-AgCl) respectively and two current peaks were completely separated. The detection limits were 0.50 ig/L (p-nitrophenol)and 1.80 ig/L (2,4-dinitrophenol). This method had been applied to the determination of nitrophenols in pol luted surface water,and the recoveries of p-nitrophenol and 2,4-dinitrophenol wer 90±6% and 86±5% respectively.