基于紫外-可见分光光度法测定食品接触橡胶中高锰酸钾消耗量

Optimization and Validation of Ultraviolet-Visible Spectrophotometric Method for Determination of Potassium Permanganate Consumption for Migrants from Food Contact Rubber

建立紫外-可见分光光度法测定食品接触橡胶中KMnO_(4)消耗量的分析方法。对反应时间、加入H_(2)SO_(4)浓度和KMnO_(4)浓度进行优化,以获得建立方法的最佳条件,并进行方法学分析。结果表明,在高锰酸钾消耗量为1 mg/kg的水迁移液中H_(2)SO_(4)和KMnO_(4)的浓度应分别超过0.1 mol/L和0.00574 mmol/L,以反应时间6 min,吸收波长525 nm,KMnO_(4)标准溶液在0.014~0.280 mmol/L范围内线性良好,相关系数(R^(2))为0.99891。检出限和定量限分别为6.8×10^(-4) mmol/和2.0×10^(-3) mmol/L。通过F检验和t检验比较,本方法与国标方法无显著差异,相对标准偏差在1.7%~7.8%之间。本方法可用于质量控制中食品接触橡胶的KMnO_(4)消耗分析。

An analytical method for the determination of manganese dioxide(KMnO_(4))consumption for migrants from food contact rubber by ultraviolet-visible(UV-Vis)spectrophotometry was established.The reaction time,and the concentration of sulfuric acid(H_(2)SO_(4))and KMnO_(4) were optimized,and the analytical figures of merit of the method were evaluated.Results showed that the concentrations of H_(2)SO_(4) and KMnO_(4) in migrant aqueous solution with KMnO_(4) consumption of 1 mg/kg should exceed 0.1 and 0.00574 mmol/L,respectively,and the optimal reaction time was 6 min.The detection wavelength was set at 525 nm.The KMnO_(4) standard solution exhibited good linearity in the range of 0.014-0.280 mmol/L,with a correlation coefficient(R^(2))of 0.99891.The limit of detection(LOD)and limit of quantification(LOQ)were found to be 6.8×10^(-4) and 2.0×10^(-3) mmol/L,respectively.F test and t test showed that the results of this method were not significantly different from those of the official redox titration method,and the relative standard deviation(RSD)was between 1.7%and 7.8%.The proposed method is useful for the analysis of KMnO_(4) consumption for migrants from food contact rubber in food quality control.