QUANTITATIVE MEASUREMENTS OF WATER AND CA RBON CONCENTRATIONS IN NATURAL BASALTIC GLASSES BY INFRARED-SPECTROSCOPY .2. WATER

Quantitative analysis by infrared spectroscopy of dissolved hydroxyl g roups in a silicate glass require a calibration of the IR molar absorp tion coefficient at the O-H bond fundamental stretching frequency. We present a new determination of this coefficient obtained on a consiste nt set of 28 samples representative of MORE composition and containing their characteristic water concentration (570-3,400 ppm H2O), which a lso guarantees the absence of dissolved molecular water. It is demonst rated that our value of 78+/-1 I.mol(-1).cm(-1) is much more precise a nd appropriate for MORE than previous determinations.