【摘要】 在酸性条件下,NO₂^-可以将I-氧化成I₂,I₂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2.0×10-4⁷.0×10-6g.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.更多还原

【Abstract】 Nitrite（ NO₂^-） can oxidize potassium iodide（ KI） reagent into iodine（ I₂） under acidic condition,and I₂ 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 × 10-4to 7. 0 × 10-6. g. m L-1has liner relation with absorbance. The regression equation of standard curve is: A =-0. 01841 + 0. 10196 c,r = 0. 9995. Using these methods,the detection limit of nitrite is 5. 0 × 10-8g. m L-1and 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.更多还原