摘要
目的建立一种特异、准确的离子色谱法测定食品中的亚硫酸盐。方法称取粉碎并混合均匀的样品置于250 ml蒸馏瓶中,在酸性条件下,通入水蒸气蒸馏;取100 ml容量瓶,加入0.3%过氧化氢溶液作为吸收液,收集蒸馏液定容至100 ml。将二氧化硫氧化成硫酸根离子后,采用ICS2000离子色谱仪测定,分析柱为IonPacAS18阴离子分析柱(250 mm×4 mm),流速1.00 ml/min;优化氢氧化钾淋洗液浓度和柱温后,以电导检测器检测,保留时间定性,外标法定量。结果当柱温40℃,KOH溶液的浓度为30 mmol/L时,硫酸根离子分离良好,峰形较佳。样品中二氧化硫的含量在26.7 mg/kg^667.0 mg/kg范围内,线性关系良好,r=0.9996;方法检出限为1.0 mg/kg;回收率在97%~101%之间;日内相对标准偏差(RSD)为3.7%,日间相对标准偏差(RSD)为6.1%。结论该法特异性强、灵敏度较高,测定结果可靠,适用于食品中亚硫酸盐的常规分析。
Objective To establish a specific and accurate method fbr determination of sulphite in food by ion chromatography. Methods The solid samples were grinded and fully mixed with semisolid homogenate or liquid samples, then placed into a 250 ml distillation flask. The target analytes were extracted with steam distillation in acidic condition. Steam was absorbed by 0.3% hydrogen peroxide solution and diluted with water in 100 ml volumetric flask. After the sulfur dioxide was oxidized into sulfate ion, the solution was separated on IonPac~ AS18 column（250 mm x4 ram） at a certain temperature with potassium hy- droxide as mobile phase at a flow rate of 1.00 ml/min, and detected by conductivity detector. The retention time was used for qualitative analysis and external standard method for quantitative analysis. Results The sulfate ion could be perfectly separated at the column temperature of 40℃, with 30 mmol/L potassium hydroxide solution as mobile phase. The calibration curve was linear in the sulfur dioxide concentration range of 26.7 mg/kg - 667.0 mg/kg （ r = 0. 9996 ）. LOD of the method was 1.0 mg/kg, the recoveries^ere between 97% - 101%. The inter - day RSD was 3.7% , and the intra - day RSD was 6.1%. Conclusion The method is specific, sensitive and reliable, it is suitable for the routine analysis of sulphite in food.
出处
《中国卫生检验杂志》
北大核心
2014年第16期2331-2333,共3页
Chinese Journal of Health Laboratory Technology
