甲基橙亚硝化极谱法测定亚硝酸根

Determination of trace amount nitrite by polarography based on its nitrosation reaction with methyl orange

研究了甲基橙亚硝化产物的极谱波行为 ,提出了亚硝化极谱法测定亚硝酸根的灵敏极谱波新体系。在 0 .6mol/L 盐酸中 ,甲基橙与 NO-2 的亚硝化反应产物在极谱仪上于 - 0 .31 V( vs.SCE)可获得灵敏的极谱波。导数波高与亚硝酸根浓度在 1 .0 9× 1 0 -7～ 1 .0 9× 1 0 -5mol/L范围内成正比 ,检出限为 6.52× 1 0 -8mol/L。研究了极谱波行为及反应机理。

In 0.6 mol/L HCl, nitrite can react with methyl orange. The nitrosation product can produce a sensitive polarographic wave at -0 31V . The derivative wave height is linear with the concentration of nitrite in the range of 1.09×10 -7 ～1 09×10 -5 mol/L with detection limit of 6.52×10 -8 mol/L. The polarographic behavior of the wave was studied and the wave was proved to be absorptive wave.The method was used to determination of nitrite in natural water with satisfactory results.