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亚硝胺是食管癌的重要化学致癌物质,但在粮食、食品、蔬菜和天然饮水中的含量甚微。亚硝酸盐广泛地存在于粮食、食品、蔬菜和天然饮水中,它与仲胺在体内可以合成亚硝胺。因此测定NO_2~-对于研究食管癌化学病因是很重要的。本文研究并改进了用盐酸萘乙二胺显色测定NO_2~-的方法。在0°～40℃范围内显色反应的产物是可溶性紫红色化合物,该化合物的最大吸收波长为545nm,达到最大吸光度仅需15分钟、最大吸光度保持恒定的时间达4小时。NO_2~-浓度在0～2.667μg/ml范围内,吸光度与浓度的关系符合朗伯—比耳定律。灵敏度为0.0333μg/ml。总之改进后方法具有灵敏、快速、重现性好和基本不受温度改变的影响等优点。
Nitrosamine is an important chemical carcinogen of esophageal cancer, but its content is negligible in food, food, vegetables and natural drinking water. Nitrite is widely present in food, food, vegetables and natural drinking water. It can synthesize nitrosamines in vivo with secondary amines. So determination of NO 2 - - for the study of chemical causes of esophageal cancer is very important. In this paper, we studied and improved the determination of NO_2 ~ - with naphthyl ethylenediamine hydrochloride. The product of the chromogenic reaction at 0 ° -40 ° C is a soluble purplish red compound which has a maximum absorption wavelength of 545 nm, a maximum absorbance of only 15 minutes and a maximum absorbance of 4 hours. NO 2 ~ - concentration in the range of 0 ~ 2.667μg / ml, absorbance and concentration in line with Lambert - Beer’s law. Sensitivity 0.0333μg / ml. In short, the improved method has the advantages of being sensitive, rapid, good in reproducibility and basically unaffected by temperature changes.