荧光光度法测定婴幼儿米粉中的亚硝酸盐

Determination of Nitrite in Infant Rice Flour by Fluorescence Spectrophotometry

目的:建立一种荧光光度法测定婴幼儿米粉中的亚硝酸盐。方法:米粉样品经60℃超声萃取,同时酶解米粉样品中的淀粉,用饱和氯化钠溶液去除样品中的脂肪和沉淀蛋白质,加入活性炭吸附消除样品浊度或色度干扰,过滤后取上清液加入2,3-二氨基萘生成2,3-萘三唑。采用荧光光度计进行检测,激发波长365 nm,发射波长450 nm。结果:亚硝酸盐在0~0.10 mg·L^(-1)具有良好线性,相关系数为0.9996,检出限和定量限分别为0.028 mg·kg^(-1)和0.085 mg·kg^(-1),回收率在94.0%~97.7%,相对标准偏差在0.17%~0.84%。结论:本研究建立了一种简单、灵敏、准确的荧光光度法,可用于测定婴幼儿米粉中的亚硝酸盐含量。

Objective:A fluorescence spectrophotometric method was established for the determination of nitrite in infant rice flour.Method:The rice flour sample was ultrasonically extracted at 60℃,and the starch in the rice flour sample was hydrolyzed at the same time.The fat and precipitated protein in the sample were removed with saturated sodium chloride solution.The activated carbon adsorption was added to eliminate the turbidity or chromaticity interference of the sample.After filtration,the supernatant was added with 2,3-diaminonaphthalene to form 2,3-naphthalene triazole.The excitation wavelength was 365 nm and the emission wavelength was 450 nm.Result:Nitrite had a good linearity in the range of 0~0.10 mg·L^(-1),the correlation coefficient was 0.9996,the limit of detection and limit of quantitation were 0.028 mg·kg^(-1) and 0.085 mg·kg^(-1),respectively.The recovery rate was 94.0%~97.7%,and the relative standard deviation was 0.17%~0.84%.Conclusion:In this study,a simple,sensitive and accurate fluorescence spectrophotometry was established for the determination of nitrite content in infant rice flour.