Influence of an Electric Field on the Emission and Absorption of Atoms and Ions in a Flame

Abstract

Experiments were carried out to explore the effect of an electric field upon atomic species introduced into a flame. The study involves components from a conventional flame atomic absorption apparatus with 10 × 10-cm parallel plate electrodes as the cathode and the 5-cm slot burner head as the anode. A marked decrease in the emission and absorption of many atomic species was observed, and quantification of the effect was carried out. The effect has been interpreted as a disturbance of the equilibrium, Me ≈ Me+ + e−. Relative decreases in absorption and emission were found to be functions of applied voltage and analyte concentration at low voltages, and constant for high voltages (≍ −2000 V). Temporal behavior of the effect has been investigated by observation of the speed of restoration of the emission signal from Na (589.16 nm), Sr (460.86 nm), and Sr+ (407.89 nm) after rapid elimination of the electric field. The effects were also studied as a function of viewing position in the flame for optimization of the position and comparison of the temporal behavior with the speed of the flame gases.

Atomic Absorption, Atomic Emission, and Flame Emission Spectrometry

“…The revival of "atom traps" continues, with reports of moderate sensitivity improvement with a slotted atom trap (255)(256)(257)(258), and a water-cooled device (259). Madden et al (260) placed electrodes across an air-C 2 H 2 flame and applied an electric field. Quantification of the resulting reduction in atomic emission and absorption intensity was performed, and reasons for this effect were suggested.…”

“…The revival of "atom traps" continues, with reports of moderate sensitivity improvement with a slotted atom trap(255- 258), and a water-cooled device(259). Madden et al(260) placed electrodes across an air-C 2 H 2 flame and applied an electric field.…”