- Author
- Turk, G. C. | Mallard, W. G. | Schenck, P. K. | Smyth, K. C.
- Title
- Improved Sensitivity for Laser Enhanced Ionization Spectrometry in Flames by Stepwise Excitation.
- Coporate
- National Bureau of Standards, Gaithersburg, MD
- Journal
- Analytical Chemistry, Vol. 51, 2408-2410, December 1979
- Keywords
- lasers | ionization | flames | spectrometers
- Identifiers
- analytical atomic flame spectrometry; laser enhanced ionization
- Abstract
- A unique approach to analytical atomic flame spectrometry called laser enhanced ionization (LEI) has recently been reported. The method relies upon the collisional ionization of electronically excited analyte atoms produced by the absorption of laser radiation to give an increase in the electrical current monitored in the flame. Results obtained using a flashlamp pumped dye laser have shown that limits approaching the part-per-trillion level can be achieved if an excited state lying withing 1-2 eV of the atom;s ionization limit can be effectively populated by laser excitation. Since experiments to date have been restricted to photons with energies less than 4.4 eV, only the low ionization potential elements have met this condition.