Analysis of ferrous alloys by spark ablation coupled to inductively coupled plasma atomic emission spectrometry

Abstract

Spark ablation coupled to excitation in a 1.2-kW argon inductively coupled plasma is applied to the direct analysis of ferrous alloys. A medium-voltage spark at a repetition rate of 400 s^–1 and a ceramic spark chamber are used for aerosol production. In low-alloyed steels detection limits for Cr, Mn, Ni, P, Si and V range from 1 to 10 µg g^–1(Mo 19 µg g^–1). When using a simultaneous spectrometer and selecting an iron line as reference, RSDs at a concentration level of 3 mg g^–1 are below 0.01. When plotting intensity ratios versus concentration ratios and using a regression function of the second degree, high-alloyed steels which contain up to 250 or 400 mg g^–1 of Ni and low-alloyed steels can be analysed using the same calibration. Preliminary measurements for the determination of carbon showed that this also applied to the determination of carbon in cast and pig iron.