Precise Measurement of the Hydrogen Isotope Composition of Phyllosilicates by Continuous Flow Off-Axis Integrated Cavity Output Spectroscopy.

New methodology is presented for analyzing hydrogen isotope ratios (D/H) in phyllosilicate minerals by laser absorption spectroscopy. D/H measurements were carried out using an off-axis integrated cavity output spectroscopy (OA-ICOS) instrument operated in a continuous flow configuration. Water was extracted from minerals in a high temperature quartz column and advanced to the analyzer in a dry air carrier gas stream.