Use of hydrofluoric acid to decrease the background signal caused by sodium chloride in electrothermal atomic absorption spectrometry Original Research Article

Electrothermal atomic absorption spectrometric measurements are frequently hindered by the presence of sodium chloride, a high background absorption signal being obtained. This drawback is reduced by the addition of hydrofluoric acid. Thus, sodium fluoride, instead of sodium chloride, is present inside the atomizer at the atomization stage and advantage can be taken of the different absorbance profiles originating during the atomization of these two chemicals. The background signals are considerably reduced at wavelengths above 240 nm and below 205 nm. No damage is caused to the pyrolytic material or quartz windows of the atomizer when solutions containing high proportions of hydrofluoric acid are used.