Atomic absorption and fluorescence spectroscopy with a carbon filament atom reservoir: The determination of gold by atomic fluorescence and atomic absorption spectroscopy with an unenclosed atom reservoir

Abstract

The atomic absorption and fluorescence characteristics of gold generated in an argon atmosphere by a carbon filament atom reservoir and a high-intensity hollow-cathode lamp are examined. Strong fluorescence signals at 242.8 and 267.5 nm were observed which yielded detection limits of 5.10 −12 and 4.10 −12 g (0.001 and 0.0008 p.p.m.), respectively. Much weaker fluorescence was also observed at 302.9 nm. Absorption signals occurred at 242.8 nm with a detection limit of 2.10 −l0g (0.04 p.p.m.). The fluorescence sensitivity is better than the best previously reported for an argon-separated oxy-hydrogen flame. Condensation reactions occur in the gas phase and lead to abnormal loss of atomic gold when 1000-fold concentrations of elements such as Ce, Cr, Cu, Fe, Mn, Mo, Ni, Pd and W are present in the gold solution. When, however, the fluorescence signals are measured immediately above the surface of the filament, with restricted field viewing, virtually all these interferences disappear.