| Dispersive liquid/liquid microextraction (DLLME) and solid phase extraction (SPE) are the novel sample pretreatment technology. DLLME is based on the ternary component solvent systems, as the formation of cloudy solution, the surface area between the extracting solvent and the aqueous sample becomes very large, so the equilibrium state is achieved quickly. The advantages of DLLME include simplicity of operation, rapidity, low cost, high recovery, high enrichment factor and environmental benignity. It can be used for Environmental and Pharmaceutical Analysis. Solid phase extraction is a method which using solid material as sorbent to extract analyte from sample solution, and then the analyte can be eluted by appropriate eluent. So it can realize the separation and enrichment of analyte. This method can be used for the separation and determination of metal ions in the wastewater. This paper is composed of four chapters.The first chapter gave a main summary for the classification and development of DLLME and SPE.The second chapter:A new direct method for log P determination by dispersive liquid/liquid microextraction (DLLME) coupled with derivatized magnetic nanoparticles (DMNPs) predispersed in1-octanol phase is discussed. First, the aim of DMNPs predispersed into1-octanol phase was to provide the magnetic force when an ultrastrong magnet was used to separate the two phases. Second, the interaction of1-octanol with inner DMNPs nuclei prevented emulsion formation in the DLLME process. The equilibrium of model compound between the two phases was reached in less than3min. The two phases were separated quickly by a super magnet because model compounds in the two phases did not interfere with each other. Moreover, interruption of absorption of DMNPs due to the partition equilibrium of the model compound was negligible. Seventeen model compounds of varied log P values were measured using this method. The log P values fell in the range of0.60to4.90, which was in agreement with the published results. This method is a rapid, accurate and facile method for direct measurement of log P values.The third chapter:A novel rapid direct method has been developed for determination of drug-protein binding by dispersive liquid/liquid microextraction (DLLME). Modified Fe3O4nanoparticles were firstly predispersed into1-octanol phase. The sample solution was added to the1-octanol phase with modified Fe3O4nanoparticles nulcea when the equilibrium of drug and serum protein binding was reached. The solution was swirled on a vortex agitator at the speed of3000rpm, the unbound drug was extracted into the1-octanol phase for its hydrophobic property. The equilibrium of free drug between the two phases was reached in5min and the two phases were separated quickly by an ultrastrong magnet. The amounts of drug concentration before and after drugs and serum protein binding were analyzed by HPLC, and then the drug-protein binding was calculated. The novel method was evaluated with6reference drugs in the drug-protein binding range from10%to100%and the results obtained were in good agreement with experimental data in the literature. This novel direct method was very quick, accurate and simple.The fourth chapter:We report on a highly reversible method for enrichment and determination of trace Cu2+by flame atomic absorption spectrometry. It is making use of pH-responsive chitosan immobilized tannin. These chitosan immobilized by the tannin exhibited a good performance for the determination of Cu2+ion. The effect of pH on the adsorption and desorption were examined by UV spectral scanning, the amount of unadsorbed Cu2+at pH1-6is coincide with the amount of Cu2+desorbed by HC1(pHl-6). The results indicated the highly reversible performance of adsorption-desorption and the pH-responsive of chitosan immobilized tannin. The function guoups of-NH2and-OH can form coordination bond with metal ions,-NH2can protonize under acid condition, so the hydrogen ions take places of metal ions in the acid condition, and the metal ions can be desorbed. The effects of adsorption time, the temperature and initial metal concentration on the adsorption rate were also examined. The adsorption follows the pseudo-second order kinetics. The adsorption-deadsorption test of the chitosan immobilized tannin was repeated10consecutive times, and the results show the good regeneration of chitosan immobilized tannin. The enrichment of Cu2+was conducted with1L of0.50mg·L-1, 0.10mg·L-1,0.020mg·L-1,0.010mg·L-1respectively, and the enrichment rate was99.81%,99.92%,99.73%,97.65%respectively. We discussed the interference to Cu2+of interference ions such as Pb2+、 Cd2+、 Zn2+、Co2+、Ni2+, and the content of Cu2+in tap water and mineral water was determinated, The recovery was95%-105%, so the method can be realized the enrichment of trace Cu2+. |
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