婴幼儿米粉中硝酸盐含量检测

Determination of nitrate content in infant rice flour

建立了一种酶解婴幼儿米粉测定米粉中硝酸盐含量的方法,解决了按照国标方法处理后滤液浑浊影响试验结果的问题。婴幼儿米粉样品经酶解后沉淀蛋白质、除去脂肪,采用间断化学分析仪测定样品中硝酸盐含量。并考察了线性、准确性、精密度和加标回收率等。结果表明硝酸盐在0～2.0μg/mL的范围内的线性良好,回归方程:y=0.2727x+0.0010,相关系数r=0.9997,相对标准偏差RSD<5%、加标回收率在86.2%～104%。结论:方法能有效解决滤液浑浊问题,操作简单、灵敏度高、重现性好。

A method for the determination of nitrate in rice flour by enzymatic hydrolysis was established.The problem that the turbidity of filtrate affects the test results after treatment according to national standard is solved.After enzymatic hydro.lysis,the protein was precipitated and the fat was removed.Nitrate content in the samples was determined by discontinuous chemical analyzer.Linearity,accuracy,precision and recovery rate are also investigated.The results showed that the ni.trate was well linear in the range of 0~2.0μg/mL,the correlation coefficients(r2=0.9997),and the recovery rate was 86.2%~104%.Conclusion:the method can effectively solve the turbidity problem of filtrate,with simple operation,high sensitivity and good reproducibility.