关键词: 茶叶；持久性有机污染物；气相色谱-串联质谱；加速溶剂萃取；分子印迹固相萃取

Abstract: A method based on gas chromatography-tandem mass spectrometry (GC-MS/MS) was developed for the determination of 68 persistent organic pollutants (POPs) including 16 polycyclic aromatic hydrocarbons, 19 phthalate esters, 18 polychlorinated biphenyls and 15 organic chlorines in various teas. Tea samples were crushed and extracted by an accelerated solvent extractor, and the extract was cleaned up by a molecular imprinted polymer solid phase extraction column, and further purified by the QuEChERS method. The analytes were separated on a DB-5ms capillary column and analyzed by GC-MS/MS, where the triple quadrupole mass spectrometer was operated in the multi-reaction monitoring (MRM) mode, effectively reducing the background interference from the tea substrate. In green tea and dark tea samples, the recoveries for the analytes were from 73.1% to 109.5% with a relative standard deviation (RSD) from 0.1% to 9.3% at three spiked concentration levels of limit of quantification (LOQ), 2-fold LOQ and 10-fold LOQ. The limits of detection (LOD) of the proposed method ranged from 0.11 to 4.3 μg/kg. In conclusion, this method can be used for accurate qualitation and quantification of the 68 POPs in tea samples. Moreover, its stability and feasibility have been verified by testing 60 batches of tea samples.

Key words: tea; persistent organic pollutants; gas chromatography-tandem mass spectrometry; accelerated solvent extractor; molecular imprinted polymer solid phase extraction