英蓝渗析离子色谱电导—紫外联用法测定食品中亚硝酸根、硝酸根的方法学研究  

Determination of nitrite and nitrate in food by metrohm inline dialysis-ion chromatography with conductivity and ultraviolet detector

作　　者：欧阳云[1] 容晓文 徐晓波[1] 谭建华[1] 宁红卫[1] 

机构地区：[1]湖南省桂阳县疾病预防控制中心,湖南桂阳424400 [2]瑞士万通中国有限公司

出　　处：《实用预防医学》2016年第2期223-226,共4页Practical Preventive Medicine

摘　　要：目的利用英蓝在线渗析技术净化处理经超声直接提取后含大量有机质及高盐的样品，建立各类食品中NO2、N03的电导、紫外联用分析方法。方法样品经切碎匀浆后，超声提取30min后，用定量滤纸过滤，弃去最初过滤液10ml，中间滤液直接置于样品管中，进样渗析分析，采用Metrosep A Supp 7—250／4．0阴离子交换柱，压力11．0MVa；柱温45℃，淋洗液为3．8mmol／L碳酸钠，流速0．8ml／min，抑制电导法检测样品的NO2^-、NO3^-，对于高盐样品串联紫外可见光检测器，在波长215nm下测定NO2^-。结果在该色谱条件下，电导检测器在36min内完成NO2、NO3的分析；标准曲线在0．05-0．5mg／L范围内线性关系良好（r=0．9998和r=0．9999）；紫外检测器NO2^-在0．05-0．5mg／L范围内线性关系良好（r=0．9999），两种检测器的样品峰面积RSD（n=7）为1．75％-2．30％；加标回收率为94．8％-107．4％。NO2^-和NO3^-的电导检测法检出限分别为0．0092mg／kg和0．017mg／kg，紫外检测器方法NO2^-检出限为0．0126mg／kg。结论该方法适用于各类不同含盐量食品中NO2、NO3^-等肮脏样品的超声提取后直接进样渗析法测定。Objective To establish determination of nitrite （NO2 ） and nitrate （NO3 ） in ultrasonic extraction of food with large amount of organic matter and high salt content by ionic chromatography based on metrohm inline dialysis - system com- bined with conductivity and UV- VIS detector. Methods Food samples were cut up , homogenized and extracted by ultra- sonic for 30 minutes. After filtration of massive samples, the middle filtrate was injected to metrohm inline dialysis system and then to ionic chromatography directly. Metrcsep A Supp 7 - 250/4.0 anion exchange column with 3.8 mmol/L Na2CO3 eluent solution at 0.8 mL/min was selected. The temperature of the column was 45℃. Suppression- conductivity detection was used to determinate NOz and NO3 in food samples. For high salt samples, UV - VIS detector was used for determination of NO2 - at the wavelength of 215 nm. Results The analysis of NO2- and NO3- using conductivity detection was finished within 36 minutes. Calibration curve obtained by conductivity detection showed good linearity in the concentration range from 0.05mg/L to 0.5 mg/L, with r = 0. 9998 for NO2 - and r = 0. 9999 for NO3 -. Calibration curve for NO2 - obtained by UV - VIS detection showed good linearity in the concentration range from 0.05mg/L to 0.5 mg/L, with r = 0. 9999. The relative standard devia- tions （RSDs, n = 7） of the two detection methods ranged from 1.75% to 2.30%. The addition standard recoveries ranged from 94.8% to 107.4%. The detection limits of NOz - and NO3 by conductivity detector were 0. 0092 mg/kg and 0. 017mg/kg respectively. The detection limit of NO2- by UV- VIS detector was 0. 0126 mg/kg. Conclusion The method of metrohm in- line dialysision chromatography with conductivity and ultraviolet detector can be used for direct determination of NO2^- and NO3^- in food samples with different salt content.

关 键 词：英蓝渗析 离子色谱 高盐食品 亚硝酸根 硝酸根 

分 类 号：R155.5[医药卫生—营养与食品卫生学]