饮用水中痕量甲醛的单扫示波极谱快速测定法

Rapid Determination of Trace Formaldehyde in Drinking Water by Oscilloscopic Polarography

目的研究用单扫示波极谱快速测定饮用水中的痕量甲醛。方法根据在0.01mol/LH3PO4底液中,甲醛与苯肼反应在峰电位Ep-0.76V(vs·SCE)处产生灵敏的二阶导数极谱波,探讨最佳分析条件及共存物质的影响。结果方法的检出限为0.002mg/L,线性范围为0.005～0.25mg/L,回收率为94.0%～103.0%,RSD为<4.0%,与国家标准方法(AHMT)结果比较,差异无显著性(P>0.05)。结论该方法每小时可测定50～60个样品,适用于饮用水中痕量甲醛的快速测定。

Objective To study a rapid method for determination of trace formaldehyde in drinking water by oscilloscopic polarography.Methods In the base solution of0.01mol/L H 3 PO 4 ,the reaction product of formaldehyde and phenylhydrazine hydrochloride on the drop mercury electrode revealed a sensitive second order derivative polarographic wave at a pick electric potential-0.76V(VS·SCE).The optimum conditions and interference by other coexisting ions were analyzed.Results The de-tection limit,linear range,recovery rate,relative standard deviation(RSD)of the method were0.002mg /L,0.005-0.25mg /L,94.0%-103.0%,and<4.0%respectively,which showed no significant difference from those of the National Standard Method(4-amino-3-hydrazino-5-mercapto-1,2,4-triazole,AHMT )(P>0.05).Conclusion The method was simple,rapid,sensitive and highly specific.The analytical speed was about 50-60samples /h,which was suitable for the determination of trace formaldehyde in drinking water.