Lithium-7 qNMR as a method to quantify lithium content in brines using benchtop NMR

Area of Science:

• Analytical Chemistry
• Materials Science

Background:

• Lithium quantification is crucial for resource evaluation.
• Existing methods like atomic absorption spectroscopy can be time-consuming and matrix-dependent.

Purpose of the Study:

• To develop and validate a novel quantitative nuclear magnetic resonance (qNMR) method for lithium analysis.
• To assess the applicability of this method for real brine samples using benchtop NMR instruments.

Main Methods:

• Development of a ⁷Li qNMR method.
• Validation including determination of limits of detection (40 ppm) and quantification (100 ppm).
• Experimental assessment of linearity, precision, and bias.

Main Results:

• The developed ⁷Li qNMR method provides accurate and precise lithium quantification.
• Excellent correlation was observed when compared to atomic absorption spectroscopy.
• The method demonstrated no significant matrix effects and required minimal sample preparation.

Conclusions:

• The novel ⁷Li qNMR method is a viable, accurate, and precise technique for lithium analysis in brine.
• Its ease of use and lack of matrix effects suggest significant potential for the mining industry.