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

Electrothermal atomic absorption spectrometric measurements are frequently hindered by the presence of sodium chloride, a high background absorption s ignal being obtained. This drawback:is reduced by the addition of hydrofluo ric acid. Thus, sodium fluoride, instead of sodium chloride, is present ins ide 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 waveleng ths above 240 nm and below 205 nm. No damage is caused to the pyrolytic mat erial or quartz windows of the atomizer when solutions containing high prop ortions of hydrofluoric acid are used. (C)1999 Elsevier Science B.V. All ri ghts reserved.