Analysis of Solids by Laser Ablation and Resonance-Enhanced Laser-Induced Plasma Spectroscopy

• Published in: Analytical chemistry (Washington) Vol. 72; no. 9; pp. 2087 - 2092
• Main Authors: Chan, S. Y, Cheung, N. H
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01-05-2000
• Subjects: Analytical chemistry; Chemistry; Exact sciences and technology; Lasers; Scientific imaging; Spectrometric and optical methods; Trace analysis; Elementary analysis; Alkali metal Compounds; Emission spectrometry; Chemical analysis; Photoionization; Sodium; Pulsed laser; Refractory material; Laser ablation technique; Laser produced plasma; Potassium Iodates
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac991242o

An analytical technique based on resonance-enhanced laser-induced plasma spectroscopy was demonstrated. Pellets of potassium iodate containing trace amounts of sodium were ablated by a 532-nm laser pulse in air. After 30 ns, the plasma plume was intercepted by a 404.4-nm laser pulse to resonantly photoionize the potassium atoms in the vapor plume. The 589-nm emissions of the sodium were found to be significantly enhanced. The enhancement was shown to depend critically on the profile of the 532-nm beam as well as the spatial overlap of the two laser pulses. Using this double-pulse scheme, the mass detection limit for sodium was estimated to be about 200 pg, which was five times better than that obtained by using the 532-nm laser pulse alone.