Flame atomic absorption spectrometric determination of magnesium in nickel-base alloys

Abstract

Flame atomic absorption spectrometry (FAAS) was employed for the determination of magnesium with wavelength 285.4 nm, slit-width 0.7 nm and air–acetylene flame (flow rates 2 and 15.5 l min^–1, respectively). A pre-treatment procedure for the determination of trace concentrations of magnesium in nickel-base alloys was developed. Matrix interferences could be effectively eliminated by the addition of both ethylenedi-aminetetraacetic acid and SrCl₂. The accuracy of the results was checked with certified reference materials of nickel-base alloys. For IN100 and Inconel alloy 718 with a certified magnesium content of 130 ± 9 and a reference value of 12 ± 5 ppm, the procedure gave values of 130 ± 3 and 7 ± 1 ppm, respectively. The detection limit was 0.50 ng g^–1 and the recovery ranged from 97 ± 4 to 104 ± 2%.