Determination of trace amounts of sulfur in steel by electrothermal vaporization inductively coupled plasma mass spectrometry

A method is described for the determination of trace amounts of S in steel by ETV-ICP-MS, The effect of Fe, Cu, Al, Si, V, Co, Ni, Cr, Mo, Ti, Mn and W on S signals and the use of KOH as a chemical modifier were studied. Most concomitant elements affected the intensity and shape of the S ETV-ICP-MS signal, The addition of KOH as a chemical modifier only partially eliminated these interference effects, The use of isotope dilution calibration and the removal of Fe by solvent extraction with 4-methylpentan-2-one were used to compensate for interference effects. A precision of +/-0.2 mu g g(-1) at an S concentration of 2 mu g g(-1) was achieved. The limit of detection for S in steel was 0.05 mu g g(-1).