The use of volcanic glass as recorder of paleoenvironmental conditions has existed for 30
years. In this paper we investigate the methodological aspects of the determination of water
content, isotopic composition, and water speciation in volcanic glass using the High
Temperature Conversion/Elemental Analyzer (TCEA) mass spectrometer system on
milligram quantities of glass concentrates. It is shown here that the precision and the
reproducibility of this method is comparable to off-line conventional methods that require …