分光光度法测定酱腌菜类食品中亚硝酸盐的实验室质量控制

目的:探讨测定酱腌菜类食品中亚硝酸盐含量的盐酸萘乙二胺分光光度法的实验室质量控制。方法:对贵阳市两城区市售的5类40种酱腌菜类食品中亚硝酸盐暴露水平进行抽样,检测方法采用盐酸萘乙二胺分光光度法测定,用样品配制成亚硝酸盐加标浓度为4.0 mg/kg的实验室内部质控样,每天平行测定1次,连续20 d,计算各次加标回收率、均值及标准差,制作准确度控制图。结果:回收率算术均值为99.8%,标准差4.32%,则上、下控制限分别为101.5%、98.1%,上、下警告限分别为:101.0%、98.6%,上、下辅助限分别为:100.4%、99.2%,20次质控样测定的回收率在98.8%~100.7%之间,有60%(12/20)的点在辅助线内,无连续7个点位于中心线的同一侧;无连续3个点位于控制限和警告限之间。40种酱腌菜类食品中亚硝酸盐浓度范围为0.08~31.23 mg/kg,亚硝酸盐检出率为57.5%,超标率为8.0%。结论:该研究采用质控方法将盐酸萘乙二胺分光光度法测定酱腌菜类食品中亚硝酸盐的结果控制在规定的误差范围内。

Quality Control of Determination of Nitrite in Pickled Vegetables Products by Spectrophotometry

Objecttive:To determinate Nitrite contents in pickled vegetables Products with the Hydrochloric Acid Naphthalene Ethylenediamine spectrophotometry and its quality control.Methods:The nitrite contents of 5 kinds ,40 sorts of pickled vegetables sampled from the two urban districts of GuiYang were determinated by spectrophotometry as soon as the samples were collected,and the laboratory internal quality was controlled in determination.Results:the Nitrite contents ranges of of 5 kinds,40 sorts of pickled vegeta...