Inductively coupled plasma-mass spectrometry (ICP-MS) has to-date not commonly been used in anal. labs. of the iron and steel industry. In order to correlate the properties of the various type of steels contg. different elemental compns., it becomes necessary to det. trace elements, which is a strength of ICP-MS. This paper describes a methodol. for the detn. of Si, an important element for steel making. Si typically is problematic using ICP-MS because of the strong interferences caused by polyat. ions produced by N, O, H, and C. The results obtained in our study show that Si can be detd. with good reproducibility and accuracy in the concn. range typically present in certified steel ref. materials. The detection limits achieved are in the single digit mg/L range.