蔬菜中硝酸盐和草酸盐的同时提取和离子色谱法测定  

IC Determination of Nitrate and Oxalate in Vegetables with Simultaneous Extraction of the Analytes

作　　者：曾芳[1] 王荣辉[1] 刘忠珍[1] 许桂芝[1] 欧俊[1] 

机构地区：[1]广东省农业科学院土壤肥料研究所广东省养分资源循环利用与耕地保育重点实验室,广州510640

出　　处：《理化检验（化学分册）》2009年第7期772-774,共3页Physical Testing and Chemical Analysis(Part B:Chemical Analysis)

基　　金：广东省农业科学院土壤肥料研究所所长基金(2008-szjj-03)

摘　　要：采用离子色谱法分析了3种浸提液对芥菜和葱中硝酸盐和草酸盐的提取效果。结果表明：用离子色谱法同时测定蔬菜中硝酸盐和水溶性草酸盐时，可直接用水提取；同时测定硝酸盐和总草酸盐含量时，选择含0．5mol·L^-1盐酸溶液2mL的浸提液效果较好；采用IonPac AS11阴离子分析柱，抑制电导检测器，淋洗液为8mmol·L^-1氢氧化钠溶液，流速为1．0mL·min^-1，进样量为25μL时，可有效分离和定量测定蔬菜中硝酸盐和草酸盐的含量，NO3^-和C2O4^2-的线性范围在20mg·L^-1以内，检出限分别为0．02，0．05mg·L^-1，相对标准偏差分别为1．8％，2．3％，硝酸盐和草酸盐的加标回收率在95．1％～103．2％，95．5％～103．6％之间。In the extraction of nitrate and oxalate from samples of vegetables （i. e. , leaf mustard and shallot）, pure water containg 2 mL of 0. 5 mol · L^-1 HCl was found to be the most effective among the 3 extractants tested. In the ion chromatographic determination, the IonPac AS11 column was used as stationary phase, and 8 mmol · L^-1 NaOH solution was used as mobile phase to elute the anions （NO3^- and C2O4^2- ） from the column in suecession Range of linearity was found within 20 mg · L^-1 for both the anions, using 25 μL as the amount of sample introduced. Detection limits （3S/N） of the method found were 0. 02 mg · L^-1 （for NO2^- ） and 0. 05 mg ·L^-1 （for oxalate）. Precision was tested with mixed standard solutions of NO3^- and C2O4^2- at different concentrations by 10 replicate sample introductions, giving values of RSD＇s of 1.8% for NO3^- and 2. 3% for C2O4^2-. Recovery of the method was tested, and the values of recovery found were ranged over 95. 1%-103. 2% for NO3^-, and 95. 5%-103. 6% for C2O4^2-.

关 键 词：离子色谱 硝酸盐 草酸盐 蔬菜 

分 类 号：TS207.3[轻工技术与工程—食品科学]