筛选了重氮组分和偶合组分。研究了重氮偶合显色反应的条件和方法,提出了借助于磺胺-J酸系列染料中间体(N-苯基J酸、J酸、双J酸)重氮偶合技术分光光度法测定亚硝酸盐。在常温溴化钾共存下,亚硝酸盐在稀盐酸溶液中与磺胺发生重氮化反应,在碳酸钠水溶液中重氮盐与J酸系列染料中间体偶合生成有色偶氮化合物。磺胺-N-苯基J酸偶氮化合物的表观摩尔吸光系数为4.63×10^4L·ml^-1·cm^-1,线性范围为0.003-0.7mg·L^-1,回收率为99.5%~101.6%。相对标准偏差为2.10%。该本方法可用于环境水体中痕量亚硝酸盐的测定。
In the present article, compounds used in diazotizing-coupling reaction were selected. The conditions and methods of diazotizing-coupling chromogenic reaction were studied. A new method of diazotizing-coupling spectrophotometry with sulfanilamide(p-aminobenzene sulfonamide) and J-Acid series dye intermediates (N-phenyl J-Acid, J-Acid, Di-J-Acid) to determine nitrite was developed. At room temperature, in the presence of potassium bromide, nitrous acid reacted with sulfanilamide in the medium of thin hydrochloric acid. Then diazonium salt reacted with N-phenyl J-Acid in the aqueous solution of sodium carbonate, forming coloured azo compounds. The apparent molar absorptivity was 4.63×10^4L·ml^-1·cm^-1 The Beer's law was obeyed in the range of 0. 003-0. 7 mg · L^-1. The recoveries were in the range of 99. 5%-101.6%. RSD was 2.1%. This method has been used for the determination of trace nitrite in the environmental water.