食品中亚硝酸盐含量测定新方法

A New Determination Method of Nitrite in Foods

在酸性条件下,NO_2^-可以将I-氧化成I_2,I_2与淀粉反应后生成蓝色络合物,此络合物在595nm处有最大吸收.食品中NO-2的浓度在2.0×10-4~7.0×10-6g.m L-1范围内与吸光度之间呈良好的线性关系,其标准曲线的回归方程为A=-0.01841+0.10196c,r=0.9995.所得方法的相对标准偏差为0.7%,检出限为5.0×10-8g.m L-1.该方法精密度和准确度高、操作简单、环境污染小.

Nitrite （NO2 ） can oxidize potassium iodide （KI） reagent into iodine （I2 ） under acidic condition, and 12 can react with starch into iodine-starch blue color complex. The maximum absorption wavelength of this complex is 595 nm. Density of Nitrite in the food is within the range of 2.0× 10^4 to 7.0× 10^-6. g. mLl has liner relation with absorbanee. The regression equation of standard curve is： A = 4）. 01841 ＋0. 10196c,r =0. 9995. Using these methods, the detection limit of nitrite is 5.0 × 10^-8 g. mLl and the relative standard deviation is 0.7 %. Therefore, this new method is simple, rapid, sensitive and accuracy, and has enormous application value in food safety determination.