Preatomization Losses in Flameless Atomic Absorption Spectroscopy

A preatomizing (charring) step is customarily used in flameless atomic absorption spectroscopy. Experiments were carried out to investigate the effect of the charring temperature on the final response and to determine at what temperature significant losses were occurring. Four elements of environmental significance (Pb, Cd, Be, V) were investigated in three matrices obtained from air pollution studies.

It was found that Pb and Cd were lost in charring above 500°C and 330°C, respectively, and that the loss rate differed for the different matrices. The maximum charring temperatures for Be and V were 900°C and 1280°C, respectively. Preatomization losses were also examined for Co, Ni, Fe and Cu in aqueous solution. Several effects which could be explained by a change in atomization rate were noted at low charring temperatures.