乙酸酐衍生GC-ECD法测定饮料中三氯蔗糖含量

摘要

A gas chromatographic (GC) method with an electron capture detector (ECD) after acetylation was developed for the determination of sucralose in drinks. Samples were diluted with water and then derivatized with acetic anhydride in the presence of 1-methylimidazole as a catalyst. Qualitative and quantitative analyses of the derivatives were achieved by GC-MS and GC-ECD, respectively. The results showed that the target derivative was 4,1’,6’-trichloro-2,3,6,3’,4’-sucrose pentaacetate (TOSPA). The calibration curve for the analyte showed good linearity in the range of 0.02–1.2 mg/mL (R=0.999 4). The limit of detection (LOD) for sucralose was 0.23 mg/kg, and the recoveries obtained by standard addition method were between 90.0% and 94.5%, with relative standard deviations (RSD, n = 6) between 0.6% and 2.5%. This method provides the advantages of low LOD, high sensitivity, less disturbance, good linearity, high accuracy and simple operation. Thus, it can be applied in sucralose analysis in drinks.%建立一种乙酸酐衍生-气相色谱-电子捕获器检测食品中三氯蔗糖含量的方法。样品经水稀释、1-甲基咪唑催化、乙酸酐衍生，生成的衍生物采用气相色谱-质谱法定性，气相色谱-电子捕获器法定量。结果表明：衍生目标物为4,1’,6’-三氯-2,3,6,3’,4’-五乙酰基蔗糖，并且在0.02～1.2 mg/mL范围内线性关系良好（R=0.9994），检出限为0.23 mg/kg，回收率为90.0%～94.5%，相对标准偏差（n=6）为0.6%～2.5%。该方法操作简单、干扰少、检出限低、灵敏度高、线性好、结果准确，能很好地满足饮料中三氯蔗糖含量的测定。