酱油中双氯丙醇的顶空固相微萃取-气相色谱-质谱法测定

Determination of Dichloropropanols by Head-Space Solid Phase Micro-Extraction Using Gas Chromatography-Mass Spectrometry in Soy Sauce

目的建立酱油中双氯丙醇(1,3-dichloro-2-propanol即1,3-DCP和2,3-dichloro-1-propanol即2,3-DCP)的顶空固相微萃取-气相色谱-质谱法的测定方法。方法采用涂层膜厚为75μm的CarboxenTM/聚二甲基硅氧烷(CAR/PDMS)的固相微萃取纤维,在50℃水浴中对酱油样品直接进行萃取30min后移至气相色谱质谱联用仪上,经DB-WAX毛细管柱(30m×0.25mm×0.25μm)分离后质谱测定,以d5-1,3-DCP为内标进行内标法定量。结果酱油样品中1,3-DCP及2,3-DCP的含量与1,3-DCP及2,3-DCP和d5-1,3-DCP内标的峰面积比呈良好的线性关系,线性范围为5～160μg/kg,相关系数大于0.998。以空白酱油为基质做了3个添加水平(5、20和50μg/kg)的加标回收实验,回收率在82.3%～113.4%之间,相对标准偏差(RSD,n=7)在2.5%～10.6%之间,方法的精密度和准确度良好。酱油中1,3-DCP和2,3-DCP的检测限分别为2和0.5μg/kg。对酱油样品进行了测定,结果满意。结论该方法简单、快速、准确、灵敏度高、无需使用有机溶剂,适用于酱油样品中双氯丙醇的直接测定。

Objective To establish a GC-MS method for the detection of 1,3-dichloro-2-propanol（1,3-DCP） and 2,3-dichloro-1-propanol（2,3-DCP） in soy sauce by using a head-space solid phase micro-extraction device.Method Extracting 1,3-DCP and 2,3-DCP from soy sauce in 50 ℃ water bath for 30 min with a CarboxenTM /Polydimethylsiloxane（CAR/PDMS,75μm） fiber.The fiber was then transferred to the injection port of GC-MS to allow the analyte absorbed and separated by DB-WAX capillary column（30 m × 0.25 mm × 0.25 μm） and detected by mass spectrometry.Using d5-1,3-DCP as the internal standard for quantification.Results The linear range for 1,3-DCP and 2,3-DCP was 5-160 μg/kg,and the detection limits were 2 and 0.5 μg/kg.The recoveries of standard addition at 5,20 and 50μg/kg were in the range of 82.3%-113.4%,and the relative standard deviations（RSD,n = 7） were in the range of 2.5%-10.6%.Satisfactory results were obtained in the detection of 1,3-DCP and 2,3-DCP in soy sauce samples.Conclusion The method is simple,fast,accurate,sensitive,and suitable for the determination of 1,3-DCP and 2,3-DCP in soy sauce.