TY - JOUR
T1 - Spectrochemical analysis of liquids using laser-induced plasma emissions
T2 - Effects of laser wavelength on plasma properties
AU - Ng, C. W.
AU - Ho, W. F.
AU - Cheung, N. H.
N1 - Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 1997/7
Y1 - 1997/7
N2 - We spectroscopically determined the temperature and electron density of the plasma plumes produced by pulsed-laser ablation of aqueous solutions containing sodium, lithium, and rubidium. With the use of a Nd:YAG laser at 532 nm and fluence of 3 J/cm2, the plasma produced was hot (low eV range) and extensively ionized, with electron density in the 1018 cm-3 range. Analyte line signals were initially masked by intense plasma continuum emissions and would only emerge briefly above the background when the plume temperature dropped below 1 eV during the course of its very rapid cooling. Since ionization was thermally induced, the intense plasma flash was inevitable. In contrast, 193-nm laser ablation at similar fluence generated plasmas of much lower (<1 eV) temperature but comparable electron density. Plasma continuum emissions were rel-atively weak, and the signal-to-background ratio was a thousand times better. Consequently, this "cold" plasma was ideal for sampling biologically important elements such as sodium, potassium, and calcium.
AB - We spectroscopically determined the temperature and electron density of the plasma plumes produced by pulsed-laser ablation of aqueous solutions containing sodium, lithium, and rubidium. With the use of a Nd:YAG laser at 532 nm and fluence of 3 J/cm2, the plasma produced was hot (low eV range) and extensively ionized, with electron density in the 1018 cm-3 range. Analyte line signals were initially masked by intense plasma continuum emissions and would only emerge briefly above the background when the plume temperature dropped below 1 eV during the course of its very rapid cooling. Since ionization was thermally induced, the intense plasma flash was inevitable. In contrast, 193-nm laser ablation at similar fluence generated plasmas of much lower (<1 eV) temperature but comparable electron density. Plasma continuum emissions were rel-atively weak, and the signal-to-background ratio was a thousand times better. Consequently, this "cold" plasma was ideal for sampling biologically important elements such as sodium, potassium, and calcium.
KW - Atomic emission spectroscopy
KW - Electron density
KW - Laser-induced plasma
KW - Plasma temperature
KW - Pulsed-laser ablation
KW - Spectrochemical analysis of liquids
UR - http://www.scopus.com/inward/record.url?scp=0031186728&partnerID=8YFLogxK
U2 - 10.1366/0003702971941638
DO - 10.1366/0003702971941638
M3 - Journal article
AN - SCOPUS:0031186728
SN - 0003-7028
VL - 51
SP - 976
EP - 983
JO - Applied Spectroscopy
JF - Applied Spectroscopy
IS - 7
ER -