分子印迹固相微萃取-敞开式离子化质谱法快速筛查牛奶中2种全氟化合物残留

Rapid screening of 2 kinds of perfluorinated compounds residues in milk by molecularly imprinted solid phase microextraction-ambient ionization mass spectrometry

中文关键词:  分子印迹聚合物  全氟化合物  固相微萃取  敞开式离子化质谱法

英文关键词:molecularly imprinted polymer  perfluorinated compounds  solid phase microextraction  ambient ionization mass spectrometry

中文摘要:

      目的 建立分子印迹固相微萃取(molecularly imprinted solid phase microextraction, MISPME)结合敞开式离子化质谱法(ambient ionization mass spectrometry, AMS)快速检测牛奶中全氟辛酸(perfluorooctanoic acid, PFOA)和全氟辛烷磺酸(perfluorooctane sulfonic acid, PFOS) 2种全氟化合物残留的分析方法。方法 牛奶样品进行蛋白质沉淀预处理后离心, 上清液经氮吹干燥后加水复溶, 在涡旋的条件下经分子印迹聚合物修饰的固相微萃取木签萃取, 在AMS和多反应监测(multiple reaction monitoring, MRM)模式下分析, 外标法定量。结果 PFOA和PFOS在0.5~500.0 μg/L的质量浓度范围内线性关系良好, 相关系数均大于0.99。PFOA和PFOS的检出限分别为0.2和0.3 μg/L, 定量限分别为0.7和0.9 μg/L, 在5、10、50 μg/L 3个添加水平下平均回收率范围均处于84.8%~89.6%之间, 相对标准偏差均小于等于8.41%。结论 分子印迹聚合物修饰的固相微萃取材料对PFOA和PFOS的选择富集性强, MISPME-AMS不需要色谱分离, 极大地提高了检测效率。该方法能快速、简便、灵敏地检测牛奶中的PFOA和PFOS。

英文摘要:

      Objective To establish a method for the rapid determination of 2 kinds of perfluorinated compounds of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) residues in milk by molecularly imprinted solid phase microextraction (MISPME) combined with ambient ionization mass spectrometry (AMS). Methods The milk samples were pretreated with protein precipitation and then centrifuged, the supernatant was dried by nitrogen blowing and re-dissolved with water, extracted by molecularly imprinted polymer-modified solid phase microextraction wooden sticks under vortex conditions, analyzed in AMS and multiple reaction monitoring (MRM) mode, and quantified by external standard method. Results The linearities of PFOA and PFOS were good in the concentration range of 0.5?500.0 μg/L with the correlation coefficients greater than 0.99. The limits of detection were 0.2 and 0.3 μg/L for PFOA and PFOS, respectively, limits of quantitation were 0.7 and 0.9 μg/L, respectively, and the average recoveries were in the range of 84.8%?89.6% at the 3 spiked levels of 5, 10 and 50 μg/L with the relative standard deviations all less than or equal to 8.41%. Conclusion The molecularly imprinted polymer-modified solid phase microextraction material has strong selective enrichment of PFOA and PFOS, and the MISPME-AMS method does not require chromatographic separation, which has greatly improved the detection efficiency. The proposed method is rapid, simple and sensitive for the detection of PFOA and PFOS in milk.