Isotopic Signatures of Lithium Carbonate and Lithium Hydroxide Monohydrate Measured Using Raman Spectroscopy.

Autor: Jones WB; Department of Global Security, 1073Savannah River National Laboratory, Aiken, SC, USA., Darvin JR; Department of Global Security, 1073Savannah River National Laboratory, Aiken, SC, USA., O'Rourke PE; Department of Global Security, 1073Savannah River National Laboratory, Aiken, SC, USA., Fessler KAS; Department of Global Security, 1073Savannah River National Laboratory, Aiken, SC, USA.
Jazyk: angličtina
Zdroj: Applied spectroscopy [Appl Spectrosc] 2023 Feb; Vol. 77 (2), pp. 151-159. Date of Electronic Publication: 2022 Dec 01.
DOI: 10.1177/00037028221131039
Abstrakt: Lithium isotopic ratios have wide ranging applications as chemical signatures, including improved understanding of geochemical processes and battery development. Measurement of isotope ratios using optical spectroscopies would provide an alternative to traditional mass spectrometric methods, which are expensive and often limited to a chemical laboratory. Raman spectra of 7 Li 2 CO 3 , 6 Li 2 CO 3 , 7 LiOH*H 2 O, and 6 LiOH*H 2 O have been measured to determine the effect of lithium isotope substitution on the Raman molecular vibrations. Thirteen peaks were observed in the spectrum of lithium carbonate, with discernable isotopic shifts occurring in eleven of the 13 vibrations, two of which have not been previously reported in the literature. The spectrum of lithium hydroxide monohydrate contained nine peaks, with discernable isotopic shifts occurring in eight of the nine vibrations, four of which have not been previously reported in the literature. The Raman spectral data reported here for lithium carbonate and lithium hydroxide monohydrate are in agreement with the previously reported works in the literature, in which the Raman active modes of these molecules were first identified and assigned. However, due to the stability and resolution of the detection system used in this work, isotopic shifts with a magnitude less than one wavenumber have been identified. Principal component regression was used to evaluate the sensitivity to isotopic content of small Raman peak shifts in Li 2 CO 3 and indicates differences greater than 2 atom% could be reliably determined. These measurements add to the body of work on lithium isotope Raman spectroscopy for these two compounds and increases the number of Raman bands which could be used for lithium isotope content analysis.
Databáze: MEDLINE