摘要
研究了对氨基苯磺酸与亚硝酸根在盐酸介质中重氮化 ,然后在氨性溶液中与 β -萘酚偶联成偶氮染料的反应 偶联产物的最大吸收波长在 485nm .据此建立了一个简单、快捷、选择性较好的测定痕量亚硝酸根的可见分光光度法 该法的表观摩尔吸光系数为 2 .3× 1 0 4 L·mol- 1·cm- 1,测定的线性范围为 0～ 2 .8mg L ,用于水和蔬菜样品中亚硝酸根的测定 。
A new spectrophotometric method for the determination of trace amounts of nitrite was developed. In acidic solution, nitrite was first diazotized with sulfanilic acid, followed by coupling with β-Naphthol to produce an azo-compound in NH 3-NH 4Cl buffer and the azo-compound has a maximum absorption at 485nm, the Beer's law of which is obeyed for nitrite in the range of 0 to 2.8 mg/L. The apparent molar absorptivity is 2.3×10 4 L.mol -1 .cm -1 . The method has good selectivity and has been applied to the determination of trace amounts of nitrite in environmental water and vegetable samples with satisfactory results.
