离子色谱法及氧化还原滴定法测定食品中二氧化硫残留量

Determination of residue of sulfur dioxide in food matrices by ion chromatography and redox titration

中文关键词:  离子色谱法  氧化还原滴定法  二氧化硫残留量  水蒸气蒸馏法

英文关键词:ion chromatography  redox titration  residue of sulfur dioxide  steam distillation

中文摘要:

      目的 建立离子色谱法测定食品中二氧化硫残留量, 并与氧化还原滴定法比对。方法 样品在酸性条件下通过水蒸气蒸馏法提取, 二氧化硫经3%过氧化氢溶液氧化吸收成硫酸根, 经阴离子分析柱分离, 电导检测器检测, 外标法定量。结果 离子色谱法与氧化还原滴定法测定结果一致。离子色谱法硫酸根在0.1~ 10.0 mg/L范围内线性关系良好, 相关系数r2=0.999, 回收率为91.91%~95.64%, 相对标准偏差(relative standard deviation, RSD)为6.40%。结论 氧化还原滴定法操作简便, 成本低, 检出限高, 但干扰因素多, 滴定终点受人为因素影响大; 离子色谱法灵敏度高、检出限低、专属性强、自动化程度高等优点, 两种方法均适合于食品中二氧化硫残留量的准确测定。

英文摘要:

      Objective To establish a method for the determination of residue of sulfur dioxide in food by ion chromatography, and compare with redox titration. Methods The sample were extracted by steam distillation under acidic conditions. Sulfur dioxide was oxidized and absorbed to form sulfate radical by 3% hydrogen peroxide solution, which separated by ion chromatograph with anion exchange column and determined by conductivity detector, then quantified by external standard method. Results The results of ion chromatography and redox titration were consistent. The linear range of sulfate was 0.10?10.0 mg/L (r2=0.999). The recoveries were 91.91%?95.64%, the relative standard deviation (RSD) was 6.40%. Conclusion Redox titration has the advantages of simple operation, low cost and high in detection limit, but the titration end point is interfered by many factors. Ion chromatography method is sensitive, specific, and automatic, and the detection limit is low. Both methods are suitable for the accurate determination of sulfur dioxide residues in food.