膜透析处理样品-离子色谱法测定奶粉中亚硝酸盐和硝酸盐  

IC Determination of Nitrite and Nitrate in Milk Powder with Sampling by Membrane-Dialysis

作　　者：扈蓉[1] 李筱翠[2] 卢晓华[3] 阚莹[3] 郭敬[3] 

机构地区：[1]深圳市计量质量检测研究院,深圳518055 [2]北京化工大学,北京100029 [3]中国计量科学研究院,北京100029

出　　处：《理化检验（化学分册）》2016年第8期901-905,共5页Physical Testing and Chemical Analysis(Part B:Chemical Analysis)

基　　金：公益性行业科研专项经费-"双打"研究专项(201204001)

摘　　要：采用膜透析处理样品-离子色谱法测定奶粉中亚硝酸盐和硝酸盐的含量。利用截留分子量为(3.5~5)kD的透析膜处理奶液,透析液经0.22μm滤膜过滤后,以不同浓度的氢氧化钾溶液为淋洗液,用紫外检测器在波长210nm处分别测定NO_2^-和NO_3^-,其线性范围依次为0.02~0.5mg·L^(-1),0.2~5.0mg·L^(-1),检出限(3S/N)依次为0.01,0.008 mg·L^(-1)。经用于实样分析,NO_2^-和NO_3^-测定值的相对标准偏差(n=6)分别为2.7%,1.9%。加标回收率在90.7%~105%之间。IC was applied to the determination of nitrite and nitrate in milk powder with sampling by membrane-dialysis. The sample solution was dialyzed with molecular weight cutoff of 3.5 to 5 kD membrane, and the dialysate was filtrated through 0. 22μm filtering membrane. The filter was eluted with KOH solutions of various concentrations. Contents of NO2- and NO3- in the elutes were determined separately by UV-detections at the wavelength of 210 nm, Linearity ranges of NO2 - and NO3- found were between 0. 02 - 0. 5 mg · L-1 , 0. 2 -- 5.0 mg· L-1 with detection limits （3S/N） of 0. 01, 0. 008 mg· L 1, respectively. In analyzing some substantial samples by this method, values of RSD＇s for NO2- and NO3- （n = 6） found were 2.7 %, 1. 9% respectively. Values of recovery found by standard addition method were in the range of 90. 7%-105% .

关 键 词：离子色谱法 膜透析 奶粉 亚硝酸盐 硝酸盐 

分 类 号：O657.7[理学—分析化学]