基于基质修饰的多次顶空固相微萃取-气相色谱法检测酒精饮料中的氨基甲酸乙酯

Multiple headspace solid-phase microextraction after matrix modification for the determination of ethyl carbamate in alcoholic beverages using gas chromatography

氨基甲酸乙酯(EC)是发酵食品在发酵或贮存过程中产生的致癌副产物。建立了多次顶空固相微萃取-气相色谱法(MHS-SPME-GC)检测多种酒精饮料中EC的方法。采用自制的溶胶-凝胶聚乙二醇/羟基硅油复合SPME萃取头提高了方法的灵敏度,加入无水硫酸钠对基质进行修饰大大提高了EC的萃取效率。在优化条件下,方法的线性范围为0.04～100mg/L,线性相关系数为0.9997,检出限为34μg/L;方法重现性好,6次重复实验所得相对标准偏差为2.19%;准确度高,加标回收率在90.9%～103.6%之间。将建立的方法用于多种实际酒样中EC的检测,其结果与标准加入法得到的结果在统计学上无显著差异。本研究表明,MHS-SPME能够克服通常存在于SPME分析中的基质干扰效应,尤其适合于大量不同基质的样品分析。

A method based on multiple headspace solid-phase microextraction（MHS-SPME） combined with gas chromatography for determining ethyl carbamate（EC） in various alcoholic beverages was established.A novel polyethylene glycol/hydroxy-terminated silicone oil fiber was used instead of commercial ones because of its high extraction ability.Anhydrous sodium sulphate was added to modify the matrix and the extraction efficiency of EC was greatly improved.The optimum conditions for MHS-SPME were as follows： extraction time,10 min;extraction temperature,35 ℃;Na2SO4 addition,4.0 mg Na2SO4 per microliter of sample;volume of sample,20 μL.The proposed method was linear in the range of 0.04 to 100 mg/L with a correlation coefficient of 0.999 7.The limit of detection was 34 μg/L and the repeatability of six replicates was 2.19%.The method was used to determine EC in various alcoholic beverages.The concentrations obtained were compared with those obtained by standard addition method and no statistically significant differences were observed.The application of MHS-SPME avoids the matrix effect,which commonly appears in SPME-based analysis.The results indicate that MHS-SPME has a great potential for EC quantification of complex samples due to its simplicity,sensitivity,reliability,ease of operation and environmental protection,especially for the analysis of a large number of samples in different matrices.