催化动力学光度法测定痕量亚硝酸根

Catalytic-kinetic photometric determination of trace amounts of nitrite

研究在稀盐酸介质中,亚硝酸根对溴酸钾氧化罗丹明B褪色的催化反应,建立测定痕量亚硝酸根的催化反应光度法.该方法测定亚硝酸根的最大吸收波长540nm,表观摩尔吸光系数为2.9×105L·mol-1·cm-1.方法检出限为8.27×10-10g·mL-1在0～6.5μg/25mL范围内符合比耳定律,用于水果、蔬菜、肉制品、罐头样品中痕量亚硝酸根的测定,结果满意.

Based on the catalytic effect of nitrite on the color fading, reaction of oxidation of rhodamine bypotassium bromate in dilute phosphoric acid solution, a catalytic kinetic photometric method fo the determination of trace amounts of nitrite was developed having its absorption maxima at 540nm. The molar absorptivity of the colour reaction was found to be 2.9×10~5 L·mol-1·cm-1, and beer's law was kept in the range of 0~6.5 ug/25 ml, of solution. The method has been applied to the determination of nitrite in several be fresh canned goods fruit and vegetable samples with satisfactory results.