离子色谱法同时测定酱油中亚硝酸盐与硝酸盐

Simultaneous Determination of Nitrite and Nitrate in Soy Sauce by Ion Chromatography

目的:建立抑制电导-离子色谱法同时测定酱油中的亚硝酸盐和硝酸盐含量。方法:样品经超声提取后,分别通过0.22μm水性滤膜、C18柱、Ag柱和Na柱,经高柱效的Dionex IonPac AS11-HC离子色谱柱分离,采用KOH淋洗液梯度洗脱和抑制型电导检测器进样分析。结果:亚硝酸盐和硝酸盐的检出限分别为0.002 mg/L和0.02 mg/L,3个水平的加标回收率为97.2%~102.5%,相对标准偏差分别为1.28%和3.99%。结论:该方法具有灵敏度高、重复性好、准确度高、样品前处理操作简便的优点,适用于酱油中亚硝酸盐和硝酸盐的检测。

Objective:To establish a method for simultaneous determination of nitrite and nitrate in soy sauce by inhibited conductivity-ion chromatography.Methods:After ultrasonic extraction,the samples are separated by 0.22μm water-borne filter membrane,C18 column,Ag column and Na column,separated by high column efficiency Dionex IonPac AS11-HC ion chromatography column,and analyzed by KOH eluent gradient elution and inhibited conductivity detector.Results:The detection limits of nitrite and nitrate are 0.002,0.02 mg/L respectively.The recoveries of the three levels are 97.2%~102.5%,and the relative standard deviations are 1.28%and 3.99%respectively.Conclusion:The method has the advantages of high sensitivity,good repeatability,high accuracy and simple pretreatment operation.It is suitable for the determination of nitrite and nitrate in soy sauce.