Development Of Ionic Liquid-based Green Sample Pretreatment For The Residue Analysis Of The Complex Matrix Sample

Sample pretreatment is a vital step in the whole sample analysis process. Traditional sample pretreatment methods, including the precipitation separation, soxhlet extraction, liquid-liquid extraction, solid phase extraction and so on, are often accompanied by a large number of pollution problems, complicated operation and time-consuming. Therefore, development of a low consumed, simple and efficient sample pretreatment has been one of hot topics. Recently, ionic liquid as an environmentally friendly solvent applied to the green sample pretreatment has attracted great attention due to its unique structure and property.Firstly, an effective and environmentally friendly ultrasound-assisted ionic liquid-based dispersive liquid-liquid microextraction coupled to HPLC method has been developed for the determination of nine hormones in cosmetics. Several factors that affect the extraction efficiency, such as the kinds and volume of ionic liquid, salt concentration, ultrasonic power and time, and centrifugation time were investigated and optimized. Secondly, an ultrasound-assisted magnetic solid-phase extraction procedure with the [C7MIM][PF6] ionic liquid-coated Fe3O4-grafted graphene nanocomposite as the magnetic adsorbent (IL-Fe3O4@G-MSPE) has been developed for the determination of five NBs in environmental water samples, in combination with HPLC-PDA. Several significant factors that affect the extraction efficiency, such as the kinds of magnetic nanoparticle and ionic liquid, the volume of ionic liquid and the amount of magnetic nanoparticles, extraction time, ionic strength, and solution pH were investigated. With the assistance of ultrasound, adsorbing NBs by IL and self-aggregating IL onto the surface of the Fe3O4@G proceeded synchronously. Attributed to the convenient magnetic separation, the Fe3O4@G could be recycled many times.Thirdly, a vortex-assisted magnetic solid-phase extraction procedure with the [C6MIM][PF6] ionic liquid-deposited Fe3O4-grafted multi-wall carbon nanotube (IL-Fe3O4@M-MSPE) as the magnetic adsorbent has been developed for the determination of five SAs in environmental water samples, in combination with HPLC-PDA. Several significant factors that affect the extraction efficiency, such as the kinds of magnetic nanoparticle, the kind of eluent, solution pH, extraction time, and the amount of magnetic nanoparticles and eluent were investigated.