改进分光光度法测定食品中的亚硝酸盐含量

Determination of nitrite in food by an improved spectrophotometry method

目的建立一种改进分光光度法测定食品中的亚硝酸盐含量。方法按照GB 5009.33-2010的方法配制标准溶液和进行样品前处理,将标准使用液经过与样品同样的前处理后再进行显色分析,比较本研究与GB 5009.33-2010的差异。结果本研究的标准曲线相关系数为0.9995,方法的回收率为98.3%~104.2%,相对标准偏差为3.2%~4.7%,样品检出限为0.3 mg/kg,定量限为1.0 mg/kg,优于国标检测方法。将标准物质与样品一起参加前处理的所有步骤,标准物质与样品具有相似的损失百分比,减少了方法系统误差对回收率的影响。结论该方法在国家标准基础上简化了前处理方法,提高了方法的回收率,减少了系统误差,对食品中亚硝酸盐的检测具有现实指导的作用。

Objective To improve the national standard method for determination of nitrite content in food by spectrophotometry.Methods The standard solution and sample pretreatment were prepared according to GB5009.33-2010.The standard solution was treated as same as the sample,colorimetric analysis was then performed,so that the differences between this study and GB 5009.33-2010 were compared.Results In this experiment,the correlation coefficient of the standard curve was 0.9995,the recovery rates were from 98.3% to 104.2%,and the relative standard deviations （RSDs） were 3.2%-4.7%.The detection limit was 0.3 mg/kg,and the quantitative limit was 1.0 mg/kg,which was superior to the national standard detection method.Pretreatment was the same for standard substance and sample,so that standard substance and sample had a similar percentage of loss,which reduced the effect of systematic error.on recovery rate.Conclusion This method simplifies the pretreatment method of the national standard detection method,improves the recovery rate of the method and also reduced the systematic error,which has a practical guiding role for the detection of nitrite in food.