The main source of elements and minerals has traditionally been mining from geological deposits in the earth. While an effective strategy for many elements, it is not the most efficient for elements which are not naturally abundant at high concentrations. In addition, for elements which are in high demand, other sources must be found.
A relatively new source of minerals is the discharge brines from desalination plants, which concentrate seawater. A variety of elements can be recovered from brines when it is more economically feasible than mining. For example, with the prevalence of battery technology, increasing amounts of lithium (Li) are required. Rubidium (Rb) and cesium (Cs) are other elements which are difficult to mine but can be extracted from desalination brines. In order to determine the economic feasibility of recovering these elements, their concentrations must be accurately determined in the brines.
This work demonstrates the ability of the Avio® 220 Max hybrid simultaneous ICP-OES to accurately measure Cs, Li, and Rb in desalination discharge brines. Although Cs, Li, and Rb can be challenging to measure with ICP-OES due to the easily ionizable element (EIE) effect, the extended wavelength range and sensitivity of the Avio 220 Max allow the use of wavelengths not normally available on other ICP-OES instruments. The result is accurate, stable, low-level measurements of Cs, Li, and Rb in desalination discharge brines, allowing for characterization of the brine to determine if these elements are present at high enough concentrations where recovery would be economically viable.