Appliaction Of Dispersive Liquid-liquid Microextraction For The Determination Of Organic Pollutants In Water Samples

With the current development of modern analytical chemistry, efficient and convenient sample pretreatment are used increasingly in real samples. However, it seems that satisfied recovery from optimal extraction method is not easily obtained for real samples than for artificial samples. Due to the complexity of matrices such as protein, matrix effect is existed and affected the present state of the target analytes. Possessing unique physicochemical properties, ionic liquids (ILs), known as "green solvents", are regarded as environmentally benign replacements for traditional toxic organic solvents and can potentially be used in sample pretreatment techniques. This thesis explored the application of ILs dispersive liquid-liquid microextraction (IL-DLLME) for the determination of organic pollutants in water samples. The main contents are as follows:Firstly, we established the ultrasound-assisted IL-DLLME method for preconcentration and determination of trace amounts of anilines in water samples. 1-butyl-3-methylmidazoliumhexafluorophosphate ([C4MIM][PF6]) is selected because it can simultaneously extract aniline compounds from water. The limits of detection were in the range of 0.1-73 ng mL-1. The developed method showed high relative recoveries for Aniline(AN),4-Fluoroaniline (4-FA),4-Nitroaniline (4-NA), 4-Chloroaniline (4-CA) at different concentrations from 90.5 to 113.3%, which ensured the accuracy of method using to detect the amount of anilines in environmental water samples.Secondly, we choose several typical nanoparticles and surfactants as matrix to investigate their effect into the established method for extraction efficiency of anilines and polycyclic aromatic hydrocarbons (PAHs). Concentrations and types of nanoparticles and surfactants, and concentration of target analytes were all considered. It was found that nanoparticles could affect the extraction efficiency of analytes with lower concentrations.Thirdly, it was found that molecularly imprinted polymers (MIPs) could not easily achieve effective imprinting factor in water system. Thus, we explored the effect of ILs on the dispersion MIP-LLE extraction. The type of MIPs was optimized. Furthermore, the performance of the IL-DLLME and IL-MIP-DLLME procedure were also compared with MIP-μSPE. Preliminary results indicated that IL could hardly affect the imprinted capacity of MIP under the experimental conditions.