Blank problems in the detection of gold by electrothermal atomisation and laser-induced fluorescence

The limit of detection of gold by electrothermal atomisation and double-resonance laser-induced atomic fluorescence can reach the low femtogram level as absolute amount of gold deposited in the furnace. At these high sensitivities, even dry firings of the graphite tube may result in a signal, which is unequivocally attributed to atomic fluorescence of the gold content of the tube released during atomisation. The occurrence and the analytical relevance of such blank signals are presented and discussed in this note.