Show simple item record

dc.contributor.authorManning, Cara C.  Concept link
dc.contributor.authorStanley, Rachel H. R.  Concept link
dc.contributor.authorLott, Dempsey E.  Concept link
dc.date.accessioned2016-03-23T14:53:29Z
dc.date.available2016-03-23T14:53:29Z
dc.date.issued2016-01-30
dc.identifier.urihttps://hdl.handle.net/1912/7896
dc.descriptionAuthor Posting. © American Chemical Society, 2016. This is the author's version of the work. It is posted here by permission of American Chemical Society for personal use, not for redistribution. The definitive version was published in Analytical Chemistry 88 (2016): 3040–3048, doi:10.1021/acs.analchem.5b03102.en_US
dc.description.abstractNoble gases dissolved in natural waters are useful tracers for quantifying physical processes. Here, we describe a field-deployable gas equilibration mass spectrometer (GEMS) that provides continuous, real-time measurements of Ne, Ar, Kr, and Xe mole ratios in natural waters. Gas is equilibrated with a membrane contactor cartridge and measured with a quadrupole mass spectrometer, after in-line purification with reactive metal alloy getters. We use an electron energy of 35 V for Ne to eliminate isobaric interferences, and a higher electron energy for the other gases to improve sensitivity. The precision is 0.7 % or better and 1.0 % or better for all mole ratios when the instrument is installed in a temperature-controlled environment and a variable-temperature environment, respectively. In the lab, the accuracy is 0.9 % or better for all gas ratios using air as the only calibration standard. In the field (and/or at greater levels of disequilbrium), the accuracy is 0.7 % or better for Ne/Kr, Ne/Ar, and Ar/Kr, and 2.5 % or better for Ne/Xe, Ar/Xe, and Kr/Xe using air as the only calibration standard. The field accuracy improves to 0.6 % or better for Ne/Xe, Ar/Xe, and Kr/Xe when the data is calibrated using discrete water samples run on a laboratory-based mass spectrometer. The e-folding response time is 90–410 s. This instrument enables the collection of a large number of continuous, high-precision and accuracy noble gas measurements at substantially reduced cost and labor compared to laboratory-based methods. Introductionen_US
dc.description.sponsorshipFunding was provided by NSF award OCE-1060840 and a WHOI Innovative Technology award to RHRS, and scholarships from NSERC and CMOS to CCM.en_US
dc.language.isoen_USen_US
dc.relation.urihttps://doi.org/10.1021/acs.analchem.5b03102
dc.titleContinuous measurements of dissolved Ne, Ar, Kr, and Xe ratios with a field-deployable gas equilibration mass spectrometeren_US
dc.typePreprinten_US


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record