Quantitative analysis of iron-rich and other oxide-based samples by means of glow discharge mass spectrometry

Glow discharge mass spectrometry has been applied to the analysis of iron-rich samples using a Fisons VG9000 mass spectrometer. Various iron ore reference materials were mixed in a 1 + 7 ratio with either copper or silver powder as a conducting host matrix. Both pin and flat geometry electrodes were prepared. Internal repeatability was seldom worse than 6%, and the external repeatability was typically better than 10% for the flat electrodes, and only slightly poorer for the pin electrodes. Linear calibration curves with correlation factors of 0.998 or better were obtained. Relative sensitivity factors were calculated and used to evaluate the effects of cooling, sample geometry and conducting host matrix. The variation in sensitivity factors for the non-conducting matrix materials under investigation (iron ores, sinters, firebrick, and bauxite) was usually < 25%.