Abstract

A glow discharge optical emission spectrometric (GD-OES) method for the simultaneous determination of C, P, S, Si, Mn, Cu, Ni, Mo, Cr, Ti, Sn, V, Al, Co and As in grey cast irons is described and demonstrated. White cast irons are used as calibrants, and a long, vigorous, presputtering routine is employed to allow stoichiometric sputtering to be attained prior to data acquisition for both the calibrants and unknowns. This approach effectively eliminates the matrix effect differences between white and grey irons that may occur in the absence of stoichiometric sputtering, thus enabling elemental determinations to be performed without type standardization. Drift correction is utilized to compensate for the effects of drifting instrument sensitivity. Data are presented and statistically evaluated to demonstrate the accuracy of the GD-OES method for each of the 15 elemental analytes. Analytical bias is shown to be inversely related to the mass fraction of the analyte in the sample. Without regard to analyte identity, the median relative bias is observed to be 1.14% when the analyte is present at mass fractions between 1 and 10%, while the median relative error is 15.1% when the analyte is present at mass fractions between 0.001 and 0.01%.