分散固相萃取-气相色谱法测定水产品中多氯联苯

Determination of PCBs in Aquatic Products by Dispersive Solid Phase Extraction-Gas Chromatography

建立气相色谱批量测定水产品中7种多氯联苯残留的分析方法。样品前处理采用超声波提取,经浓硫酸磺化后引入分散固相技术进行净化,考察不同条件下多氯联苯的提取分离效果并考虑水产品基质干扰的因素,利用气相色谱-电子捕获检测器测定7种多氯联苯含量,采用内标校正。结果表明：7种多氯联苯在0.005~0.2μg/m L质量浓度范围内具有良好的线性关系,相关系数0.999 86~0.999 97;样品中添加量为2~100μg/kg时,回收率为80.4%~118.0%,相对标准偏差为1.9%~7.3%,检出限为（RSN=3）0.4~0.8μg/kg,定量限（RSN=10）1.3~2.7μg/kg。该方法操作简单、方便快速、重复性好,适用于批量监测水产品中多氯联苯残留的分析。

This paper establishes a method for the batch analysis of seven polychlorinated biphenyls（PCBs） residues in aquatic products by gas chromatography. The sample was extracted by ultrasonic assistance, and the extract was then sulfonated with concentrated sulfuric acid before purification by dispersive solid-phase extraction（d-SPE）. The efficiencies of extraction and separation of PCBs were examined under different conditions and matrix interferences from aquatic products were taken into account as well. Seven PCBs were detected by gas chromatography with electron capture detector and quantitated using an internal standard calibration method. The results showed that the calibration curves of seven PCBs had a good linearity within the concentration range of 0.005–0.2 μg/m L with correlation coefficient of 0.999 86–0.999 97. The recoveries at spiked concentration levels of 2–100 μg/kg were 80.4%–118.0%, with relative standard deviations between 1.9% and 7.3%. The limit of detection（RSN = 3） was 0.4–0.8 μg/kg, and the practical quantification limit（RSN = 10） was 1.3–2.7 μg/kg. The method was characterized by simple operation, rapid detection and good reproducibility, and was suitable for the batch analysis of PCBs residues in aquatic products.