“…Some traditional methods, such as solid-phase extraction [ 7 , 8 ], stir bar sorptive extraction [ 9 ], liquid–liquid extraction [ 10 , 11 , 12 , 13 ], etc., have some disadvantages, like the consumption of a large volume of organic solvent, low extraction efficiency and poor sensitivity. Solid-phase microextraction (SPME) proposed by Pawlinszyn in 1989, not only overcomes the above shortcomings [ 14 , 15 , 16 ] but can also couple with gas chromatography (GC) [ 13 , 17 ], high-performance liquid chromatography (HPLC) [ 18 ] and other instruments. In particular, in-tube solid-phase microextraction (IT-SPME), which can be combined with HPLC [ 19 , 20 , 21 ], has been widely used in environmental, food, pharmaceutical and other analytical applications.…”