Spark ablation inductively coupled plasma mass spectrometry analysis of minor and trace elements in low and high alloy steels using single calibration curves

A unidirectional high current pulse spark with a very fast rise-time, ensur ing a rapid and complete transfer of energy to the sample, was used as the sampling system for the analysis of carbon steels and highly alloyed steels with the same operating conditions. The sparking operating conditions were optimised and a restrictive path was designed to decrease the quantity of eroded material reaching the plasma, in order to prevent deposition of mate rial in the torch injector, and to minimise sampling cone blockage and drif t effects. Spark ablation sampling efficiency and effectiveness of the rest rictive path were evaluated. To compensate for differences in the amount of material ablated or for a variation in drift, Fe-57 and Mn-55 were used as internal standards. The calibration procedure was applied to the analysis of the elements Al, B, Co, Cu, Mn, Nb, P, Si, and V, present in the followi ng certified reference materials: BCS (Bureau of Analysed Samples) SS-456 t o SS-460 (residual series); CRMs (European Committee for Iron and Steel Sta ndardisation) No 285-2 (Maraging steel), No 292-1 (niobium stabilised steel ), No 295-1 (highly alloyed steel), and No 296-1 (jethete steel). When plot ting intensity ratios (I-X/I-IS) versus concentration ratios (C-X/C-IS) lin ear calibration curves over the entire range of tested concentrations, with correlation coefficients better than 0.999, were obtained. Determination l imits below 1 mu g g(-1) were found and the precision was better than 2.8%. It has also been shown to determine carbon contents at concentration level s greater than 0.03% with RSD values below 3%. For the elements As, Sn, Ti, W and Zr, only present in one or two of the Standard Materials, the sensit ivity was also evaluated. Furthermore, the possibility of obtaining reprodu cible transient signals from sparking periods of only a few seconds was dem onstrated.