食品中亚硫酸盐的离子色谱法测定

Determination of sulfite in food by ion chromatography

建立了食品中亚硫酸盐的离子色谱检测方法。样品采用40mmol／L NaOH溶液提取，甲醛作稳定剂，经ENVI-Carb活性碳小柱除去提取液中的色素，石油醚除去提取液中的油脂，用配有电导检测器的离子色谱仪测定。以AS9-HC为色谱柱，流动相为8mmol／L Na2CO3-2．5mmol／L NaOH，亚硫酸盐的残留量在0-6．0mg/L的范围内线性关系良好，相关系数为0．9989，相对标准偏差为1．3％～9．1％，回收率在88．4％。98．1％之间。

A method for the determination of sulfite in food by ion chromatography has been established. The samples were extracted with 40mmol/L NaOH and reacted with formaldehyde to form hydroxymethyl sulfonic acid. The pigment and fat were removed with ENVI-Carb cartridge and petroleum ether, respectively. Then the derivation, hydroxymethyl sulfonic acid, was determined with ion chromatography equipped with a conductance detector, quantified by an external standard method. In the method AS 9-HC chromatographic column was used and the mobile phase was 8 mmol/L Na2 CO3-2.5 mmol/L NaOH. The linear range for sulfite residue is 0 - 6.0 mg/L with the correlation coefficient of 0.9989, relative standard deviations and recoveries are 1.3% -9.1% and 88.4% -98.1%, respectively. The method is proved to be rapid, accurate and practical.