Low Field Heteronuclear NMR (13C, 19F, 7Li, 23Na) for Determining Lithium Concentration in Aqueous Solutions
Location
Poster #14
Department
Chemistry
Abstract
Lithium is a crucial element required for rechargeable batteries, such as those used in electric vehicles. Currently, lithium is mined via water extraction, however, other elements are present in the extract solution, such as sodium, and these must be removed as part of the purification process. While atomic absorption (AA) spectrometry is commonly used to measure concentrations of inorganic ions in solution, sodium’s spectrum is so broad that it interferes with the determination of lithium. However, nuclear magnetic resonance spectroscopy is able to detect the presence of lithium in the presence of sodium, and can be calibrated to determine the concentration of both ions. This method of detection is ideal for characterizing nonpolar extraction solvents that are intended to simplify the purification of lithium. In this work we use a low field (1.4 Tesla, 60 MHz for 1H) FT-NMR spectrometer tuned simultaneously to fluorine and one other nucleus: lithium, sodium, or carbon, to measure the differential solubility of lithium over sodium in toluene, fluorobenzene, and various commercial extraction solvents. These results will be presented.
Faculty Sponsor
Donald Bouchard
Faculty Sponsor
Charles Abrams
Low Field Heteronuclear NMR (13C, 19F, 7Li, 23Na) for Determining Lithium Concentration in Aqueous Solutions
Poster #14
Lithium is a crucial element required for rechargeable batteries, such as those used in electric vehicles. Currently, lithium is mined via water extraction, however, other elements are present in the extract solution, such as sodium, and these must be removed as part of the purification process. While atomic absorption (AA) spectrometry is commonly used to measure concentrations of inorganic ions in solution, sodium’s spectrum is so broad that it interferes with the determination of lithium. However, nuclear magnetic resonance spectroscopy is able to detect the presence of lithium in the presence of sodium, and can be calibrated to determine the concentration of both ions. This method of detection is ideal for characterizing nonpolar extraction solvents that are intended to simplify the purification of lithium. In this work we use a low field (1.4 Tesla, 60 MHz for 1H) FT-NMR spectrometer tuned simultaneously to fluorine and one other nucleus: lithium, sodium, or carbon, to measure the differential solubility of lithium over sodium in toluene, fluorobenzene, and various commercial extraction solvents. These results will be presented.