Isotopic analysis of 28Si-Enriched silicon using laser mass spectrometry

A procedure for the isotopic analysis of Si-28-enriched silicon by laser mass spectrometry is described. The procedure is based on the analysis of a dry concentrate or a film obtained by the pneumatic nebulization of an analyte and an internal standard solution or by the laser sputtering of a solid phase onto a support of a high-purity substance. The range of determinable isotope concentrations is (100-n x 10(-6)) at %; the total error in determining the major isotope is n x 10(-2) at % at an enrichment factor higher than 99%. The procedure provides the simultaneous control of 70 impurity elements in the sample.