The Application Of Novel Liquid Phase Microextraction Techniques Based On Ionic Liquids In Sample Pretreatment

The developments of time-saving, efficient, environmentally friendly novelsample pretreatment techniques have been a hot topic in analytical chemistry in recentyears. Liquid phase microextraction techniques based on ionic liquids is a novelsample pretreatment technique with the advantages of simple device, less solvent,economic, simplicity of operation and easy to follow-up analysis. In line with theminiaturization of modern analytical science and the requirements of theenvironmentally friendly sample pretreatment technology. On the base of thesystematic study of the applications of liquid microextraction techniques based onionic liquids in the field of samples pretreatment process, this paper has built novelanalysis system that liquid microextraction techniques based on ionic liquids coupledto some decetion techniques. This study extends the application scope of liquid-liquidmicroextraction in samples pretreatment.This paper is divided into four chapters, each chapter is summarized as follows:Chapter one comprised a brief introduction of the developing situation ofsamples pretreatment technology and the composition, classification, characteristicsof ionic liquids. The application of liquid phase microextraction techniques based onionic liquids in sample pretreatmen in various fields consisted of extraction of metalions, biological activity and small organic molecules were also reviewed. Based onthe investigation of related literature, the outline and significance of this paper wereproposed.In chapter two, the hydrophobic ionic liquids was used for the extraction ofcaffein. Parameters that might affect the extraction efficiency such as extraction time，the phase volume ratio, the pH values of aqueous phase, the mass of salt wereexamined. The extraction process was miniaturization, and caffeine was decetecd byUV spectrophotometry. The method were miniaturization, environment friendly, meetthe requirement of modern analytical chemistry, provide a new clue for the detectionof caffeine.In chapter three，the rapid determination of Ferrum(Ⅲ) ions in environmental water samples by the liquid phase microextraction techniques based on ionic liquids-digital colorimetry(DIC) was investigated. The spot gray scale integral value wasproportional to the concentration of Fe3+. Thus a novel determination method ofFerrum(Ⅲ) ions in water sample based on ILS-LLME-DIC has been developed. Inthis work, a new liquid phase microextraction techniques termed Aqueous two-phasemicroextraction based on ionic liquids, for the first time, was developed. Andcompared this method with ILS-DLLME, the results keep in line with AAS. Thismethod was proven to be low cost, simple, rapid, highly sensitive andenvironmentally friendly which can meet the requirements for field detection.In chapter four, determination of malachite green (MG) and crystal violet (CV)in water samples with ionic liquids based dispersive liquid liquid microextraction(DLLME) and aqueou two phase microextraction (ATPME) coupled to UVspectrophotometry was investigated in this work. Some important parameters thatinfluence the extraction efficiency and the enrichment factor were studied andoptimized. In this work, we founded that the proportion of salt in aqueou two phasemicroextractions (ATPME) was adjusted to reverse the extraction phase. Thesensitivity of UV spectrophotometry increased by preconcentration of malachite green(MG) and crystal violet (CV).