Isotope-ratio-monitoring of O-2 for microanalysis of O-18/O-16 and O-17/O-16 in geological materials

Experiments were performed to test the viability of using isotope-ratio-monitoring gas-chromatography mass spectrometry (irm-GCMS) as a means for isotopic analysis of nanomole quantities of O-2 released in a vacuum system suitable for laser extraction and fluorination. Several sources of error were identified and eliminated, including false signals from extraneous scattered ions and adsorption of O-2 to metal surfaces. Results show that with appropriate attention to these potential impediments, coupling high-precision irm-GCMS to laser sampling of microgram quantities of silicate and oxide minerals is feasible. Copyright (C) 1998 Elsevier Science Ltd.