离子色谱法测定酱腌菜中的二氧化硫

Determination of sulfur dioxide in pickles by ion chromatography

建立离子色谱法测定酱腌菜中的二氧化硫含量。样品加入盐酸后采用水蒸气蒸馏,以过氧化氢溶液吸收蒸馏释放出的二氧化硫,通过0.45μm滤膜和Ag柱去除杂质,采用AS11-HC阴离子交换色谱柱分离,以KOH淋洗液洗脱,用电导检测器测定。在优化的色谱条件下,硫酸根标准溶液的质量浓度在1.80~18.00mg/L范围内与色谱峰面积呈良好的线性关系,相关系数为0.9997,硫酸根的检出限为0.006mg/L。样品的加标回收率为76.9%~92.3%,测定结果的相对标准偏差小于10%(n=6)。该方法样品前处理简单,灵敏度高,可用于酱腌菜中二氧化硫的测定。

A method was establishd for the determination of sulfur dioxide in pickles by ion chromatography. Samples of pickles were distilled under acidic conditions,and the sulfur dioxide produced was absorbed into hydrogen peroxide solution and oxidized into sulfate ion.Then the solution was filtered with 0.45 μm filtering menbrane and Ag cartridges so as to remove the impurities.The filtrate was separated by AS11-HC separation column,and determined by the electrical conductivity detector after being eluted with potassium hydroxide solution.The results showed that the mass concentration of sulfate standard solution had good linear relationship with chromatographic peak area in the range of 1.80-18.00 mg/L under optimized chromatographic conditions.The correlation coefficient was 0.999 7,and the detection limit for sulfate was 0.006 mg/L.The recoveries were between 76.9% and 92.3% and the relative standard deviation of determination results were all less than 10%(n=6).This method had the advantages including simple operation and higher sensitivity,which could meet the determination requirements of sulfur dioxide in pickles.