| Summary: | 碩士 === 國立交通大學 === 應用化學系 === 90 === Hydrophilic metal ions can be extracted from aqua by organic solvent with proper organic chelating agent. Nevertheless, a new problem comes from the great volume of organic solvent containing metal ions. Supercritical fluids can replace conventional organic solvents in extraction process. When degassing at collecting, such fluids separate from extracts suddenly and concentrate them, which can reduce the waste volume. We try to use R134a (1,1,1,2-tetrafluoroethane) instead of supercritical carbon dioxide, a widely utilized solvent, and recognize that R134a has appreciable solvency while the working pressure is 100 atm lowered. Polar compounds showed low solubility in SF-CO2, unless fluorinated compounds or modifier are used, but this drawback is overcome in using R134a. Recent researches show that adding surfactant during extraction improves efficiency and even metal ions can be extracted through microemulsion without chelating agent, we also prove this idea in our experiment. This is momentous for metal ions extraction from a complicated matrix. Quantitative calculation is based on UV/Vis absorbance data; information herein includes solubility, partition coefficient and recovery of sample extraction.
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