Laser-excited atomic fluorescence spectrometry using graphite tube electrothermal atomisation and double-resonance excitation

Abstract

Laser-excited atomic fluorescence spectrometry using double-resonance excitation and graphite tube electrothermal atomisation is evaluated for the determination of trace elements. Two dye lasers pumped by a Nd: YAG laser were used to excite atoms inside a graphite tube furnace simultaneously. Collisional coupling between the highest level reached by the laser excitation and nearby levels resulted in several fluorescence transitions in the ultraviolet region for each specific element. The fluorescence was collected at 90° by combining a pierced plane mirror, a plano-convex MgF₂ lens and a double monochromator equipped with a solar blind photomultiplier tube. The detection limits of In, Ga and Yb were 2, 1 and 220 fg, respectively.