PNNL

Abstract

The analytical performance of tunable laser absorption spectroscopy (LAS) for the detection of Li in laser-produced plasmas is evaluated. NIST SRM glasses with Li concentrations ranging from 1-500 ppm by mass are ablated under low-pressure conditions, and the Li absorption is probed using fixed-wavelength detection and scanned spectral detection. Optimum conditions for averaging in time and by number of ablation shots are determined, and calibration curves are generated. For fixed wavelength measurement, a 180 ppb single-shot limit of detection (LOD) is determined, improving to 6 ppb with averaging over 1000 ablation shots. For spectral measurement, a LOD of 17 ppb is achieved in 40 s.