Improvement of detection limits in laser-excited atomic fluorescence flame spectrometry

Journal Article · Wed Feb 01 04:00:00 EST 1978 · Anal. Chem.; (United States)

DOI:https://doi.org/10.1021/ac50024a047· OSTI ID:5142148

Weeks, S J; Haraguchi, H; Winefordner, J D

Laser-excited atomic fluorescence flame spectrometry with a pulsed nitrogen laser pumped tunable dye laser has been investigated with respect to analytical figures of merit, especially in terms of improvement of detection limits. The detection limits for 19 elements in an air-acetylene flame and for 5 elements in a nitrous oxide-acetylene flame are evaluated in the cases of both resonance and nonresonance atomic fluorescence lines. The detection limits obtained have been improved about 10 to 200 times. Detection limits for many elements excited by the frequency doubled dye laser output are reported for the first time. Now, most elements examined can be detected at the ng ml/sup -1/ (ppB) level or less with analytical curve linearities of over five orders of magnitude. Improvement of the detection limits was achieved mainly by expanding the diameter of the laser beam to illuminate a larger analyte volume in the flame and by using a low dispersive spectrometric system. The optical arrangement employed reduced the scatter signal and improved the signal-to-noise ratio (SNR). Although a low dispersive spectrometric system (spectral bandwidth of ..delta..lambda/sub M/) was employed, the spectral resolution of the system was determined by the spectral bandwidth of the laser, ..delta..lambda/sub L/(..delta..lambda/sub L/ much less than ..delta..lambda/sub M/). Conditions for optimizing analytical results are discussed. The results indicate that laser-excited atomic fluorescence spectrometry is potentially superior to atomic absorption spectrometry, atomic emission flame spectrometry, atomic emission induction coupled plasma spectrometry, and conventional source atomic fluorescence spectrometry, in terms of analytical figures of merit.

• Research Organization: Univ. of Florida, Gainesville
• OSTI ID: 5142148
• Journal Information: Anal. Chem.; (United States), Journal Name: Anal. Chem.; (United States) Vol. 50:2; ISSN ANCHA
• Country of Publication: United States
• Language: English

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