holder

The following is an abstract for the selected article. A PDF download of the full text of this article is available here. Members may download full texts at no charge. Non-members may be charged a small fee for certain articles.


Trace Metal Detection by Laser-Induced Breakdown Spectroscopy

Volume 53, Number 10 (Oct. 1999) Page 1226-1236

Wal, Randall L. Vander; Ticich, Thomas M.; West, Joseph R.; Householder, Paul A.


Laser-induced breakdown spectroscopy (LIBS) has been widely pursued for trace elemental determination in gases, solids, and liquids. Application to liquids has proved problematic due to high spatial confinement of the LIBS plasma and rapid quenching of the excited-state emission. This work presents an alternative approach to trace metal determination in liquids in which 1.0 mL of liquid is deposited onto a carbon planchet and then evaporated, thus transforming the liquid analysis to a solid surface analysis. Using optimized excitation and detection conditions, we have identified spectral regions for sensitive detection of 15 metals (Mg, Al, Si, Ca, Ti, Cr, Fe, Co, Ni, Cu, Zn, As, Cd, Hg, Pb). The limit of detection (LOD) for the technique ranged from 10 ppb to 10 ppm for these elements. A 100 ppb LOD represents detection of 130 picograms of metal (approximately 2 picomoles) in a single measurement calculated from the laser spot size on the sample. Scanning electron microscopy (SEM) images and energy-dispersive X-ray (EDX) spectra of the samples provide insight into the observed reproducibility and linearity of the technique for several of the metals studied.