建立婴幼儿米粉中硝酸盐和亚硝酸盐的在线超滤-离子色谱测定方法.样品经超声提取,3%乙酸沉淀蛋白质后,低温离心,取上清液依次过C18小柱,Ag柱、Na柱,经在线超滤装置自动净化样品,由电导检测器检测样品中的硝酸盐和亚硝酸盐含量.硝酸盐(以NO3-计)和亚硝酸盐(以NO2-计)分别在0.10 mg/L~2.0 mg/L和0.010 mg/L~0.20 mg/L的范围内线性良好,相关系数R2均大于0.9999.方法的硝酸盐(以NO3-计)检出限为0.2 mg/kg,亚硝酸盐(以NO2-计)检出限为0.1 mg/kg,硝酸盐回收率为89.8 %~96.1 %,亚硝酸盐回收率为89.5 %~96.0 %.此法所获得结果准确可靠,重复性良好,实现对婴幼儿米粉中硝酸盐和亚硝酸盐的准确定量分析.%A method was established for the determination of nitrate and nitrite in baby rice flour by ion chromatogrephy-inline ultraflitration.After ultrasonic extraction,protein precipitation using 3 % acetic acid, and centrifugaion at low temperature, the supernatant was filtered through C18column, Ag column and Na column for injection analysis. And then it was analyzed by Ion chromatogrephy-inline ultraflitration, and the conductivity dectector was used to detect nitrate and nitrite in baby rice flour. The lineal range of nitrate in 0.10 mg/L-2.0 mg/L and the lineal range of nitrite in 0.010 mg/L-0.20 mg/L was with high correlation coefficients(R20.999 9).This method detection limit was 0.2 mg/kg for nitrate(based on NO3-),0.1 mg/kg for nitrite(based on NO2-).The recovery rate of nitrate was 89.8 %-96.1 %,and the recovery rate of nitrite was 89.5 %-96.0 %.This method was accurate,reproducible,and suitable for determination of nitrate and nitrite in baby rice flour.
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