Zircon water content: reference material development and simultaneous measurement of oxygen isotopes by SIMS

Abstract

Zircon water content is an important physicochemical parameter for many geological processes, yet its measurement by the secondary ion mass spectrometry (SIMS) technique is hampered by the lack of suitable reference materials and high water background, especially if large-geometry (LG)-SIMS is used.

Optimization of SIMS analytical parameters for water content measurement of olivine

“…The internal and external precision of oxygen isotope measurements of San Carlos olivine is <0.41‰ (2SE) and <0.53‰ (2SD), respectively. We noted that both of them are marginally higher in the San Carlos olivine, while 1.5 to 2 times in the other three olivine samples than that of normal oxygen measurement (<0.32‰, 2SE and <0.30‰, 2SD) or simultaneously high‐precision measurement of water content and oxygen isotope (0.40‰, 2SE and 0.40‰, 2SD) …”

“…The energy slit was set to 50 eV with 5 eV gap. Although we focused on water content measurement, the oxygen isotope compositions were also simultaneously measured with the multicollector system to compare with our previous data. Two Faraday cup detectors, located on L'2 and H1 trolleys with 10 10 and 10 11 Ω amplifiers, and an electron multiplier of monocollector were used to measure the 16 O − , 18 O − , and 16 O 1 H − , respectively.…”

“…Fourier transform infrared (FTIR) spectroscopy is most commonly used to determine the water content and its species in glasses and minerals . It has the capacity to measure low hydrogen abundance and to provide information on hydrogen species with very high special resolution .…”

“…This requirement limits the application of FTIR to small‐sized samples (<100 μm) . Secondary ion mass spectrometry (SIMS) provides insitu micromeasurements of elemental and isotopic compositions in selected millimeter‐ to centimeter‐sized solid sample for almost all elements in nature and is ideal for measuring the water content in NAMs . Moreover, SIMS can simultaneously yield water content and oxygen isotope compositions, which are essential to trace the origin of water .…”

“…1 Fourier transform infrared (FTIR) spectroscopy is most commonly used to determine the water content and its species in glasses and minerals. 2 It has the capacity to measure low hydrogen abundance and to provide information on hydrogen species with very high special resolution. 3 However, the samples to be analyzed by this technique need to be of such a dimension that allows wafers to be manufactured, typically around 100 μm thick and double polished.…”