“…In recent years, some sample pretreatment techniques, such as conventional liquid–liquid extraction (LLE) [ 17 , 18 ], solid-phase adsorption-based extraction techniques such as solid-phase extraction (SPE) [ 19 , 20 , 21 ], solid-phase microextraction (SPME) [ 22 , 23 ], stir-bar sorptive extraction (SBSE) [ 24 ], dispersive solid-phase extraction (dSPE) [ 25 , 26 ], and magnetic solid-phase extraction (MSPE) [ 11 , 27 , 28 , 29 ], have been successfully applied to purification and separation of QAs from the complex samples. Numerous types of adsorbents, such as molecularly imprinted polymers, carbon materials, metal-organic frameworks, and covalent organic frameworks (COFs), have been utilized as the adsorbing materials for the extraction of QAs [ 30 ].…”