Authors: Yuji Sano Naoto Takahata
Publish Date: 2005/06/01
Volume: 61, Issue: 3, Pages: 465-473
Abstract
A quadrupolebased mass spectrometric system for determining noble gas He Ne Ar Kr and Xe abundances in a liquid sample has been developed and applied to seawater equilibrated with the atmosphere at several temperatures After known amounts of isotopic spikes 22Ne 36Ar 86Kr and 124Xe were introduced into the preparation vacuum line dissolved gases were extracted from seawater and well mixed with the spikes by ultrasonic vibration Noble gases were purified using threestage hot Ti getters and separated by two activated charcoal traps held at low temperature liquid nitrogen and dry ice—ethanol Noble gas abundances were measured by a relatively inexpensive quadrupole mass spectrometer based on the isotope dilution technique Precisions obtained by repeated measurements for He Ne Ar Kr and Xe are 15 04 04 04 and 06 respectively Noble gas abundances in airsaturated seawater at eight temperature steps 10°C 55°C 100°C 144°C 170°C 213°C 246°C and 296°C were measured using the analytical system The overall variation of the abundances with temperature agrees well with those of NaCl brines reported in the literature We propose here new constants to fit observed data to empirical equation of noble gas solubility in seawater with its temperature variation
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