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,然后在氨性缓冲溶液中与间苯二酚偶联成偶氮染料的反应。偶联产物的最大吸收波长在430nm,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光分光光度法,其表观摩尔吸光系数为3.6×10~4L·mol^(-1)·cm^(-1),测定的线性范围为0～2.0mg/L,用于水和蔬菜样品中痕量亚硝酸根的测定,结果满意。
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 resorcinol to produce an azo - compound in NH3 - NH4Cl buffer and the azo - compound has a maximum absorption at 430nm, the Beer' s law of which is obeyed for nitrite in the range of 0 to 2.0 mg/L. The apparent molar absorptivity is 3.6×104 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.
