总膳食中硝酸盐和亚硝酸盐的测定

Determination of Nitrite and Nitrate in Total Diet

目的建立离子色谱法/电导检测器同时测定总膳食中亚硝酸盐和硝酸盐的方法。方法通过优化前处理步骤和分离条件,采用离子色谱法/电导检测器同时测定总膳食中的硝酸盐和亚硝酸盐含量。结果通过色谱条件优化,使复杂基质条件下Cl-和NO-2达到基线分离,NO-2和NO-3灵敏度提高。本方法的检出限亚硝酸盐为0.40mg·kg-1,硝酸盐为4.0mg·kg-1,线性范围NO-2:0.02~2mg·L-1,NO-3:0.2~20 mg·L-1。亚硝酸盐平均回收率为92.7%~119.3%,硝酸盐平均回收率为90.2%~109.3%,RSD均小于10%,并得出福建省各类总膳食样品中亚硝酸盐和硝酸盐的含量。结论本方法成功建立了适用于各种基质复杂的膳食样品中亚硝酸盐和硝酸盐的检测方法。

OBJECTIVE A method for simultaneous determination of nitrite and nitrate in total diet by ion chro- matography/conductivity detector was established. METHODS By optimizing the pretreatment procedure and the separation conditions, the method of ion chromatography/conductivity ruination of nitrate and nitrite in the total diet. RESULTS Through detector was established for simultaneous deterthe optimization of chromatographic conditions, 5mmol · L-1 NaOH as eluent can make Cl-and NO2- reached the baseline separation under the complex matrix,This chromatographic conditions was sensitive and accurate. The detection limit for nitrite and nitrate were 0. 40mg·kg- and 4. 0mg· kg-1 respectively. The linear range for nitrite and nitrate were 0. 02 - 21μg· mL-1 and 0. 2· 20μg · mL-1 respectively. The mean recovery of nitrite was 92. 7% - 119. 3% ,the mean recovery of nitrate was 90. 2% - 109. 3% ,the RSD was less than 10%. And the content of nitrite and nitrate in all kinds of total dietary samples was obtained. CONCLUSION Based on the determination of nitrite and nitrate in food,a method for the determination of nitrite and nitrate was successfully established in various dietary samples with complex matrix.