动力学光度法测定食品中痕量亚硝酸根

Determination of Trace Nitrites in Foodstuffs by Kinetic Spectrophotometry

基于稀H3PO4介质中,痕量亚硝酸根对高碘酸钾氧化结晶紫的褪色反应有明显的催化作用,建立了痕量亚硝酸根的动力学光度测定法,方法检出限为0.06μg/L,线性范围为0～4.0μg/L。用于测定食品中的痕量亚硝酸根,结果与Griess法相符,6次测定结果的RSD≤5.0%。

A new kinetic spectrophotometric method for the determination of trace nitrites has been developed. The method was based on the catalytic effect of trace nitrites on crystal violet oxidation of potassium periodate in dilute phosphoric acid solution. The detection limit was 0.06 μ g/L with linear range of 0～4.0 μ g/L. The method has been applied to the determination of trace nitrites in water samples. The results was in agreement with those provided by Griess method with precision of ≤ 5.0% RSD （n=6）.