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Published August 1978 | public
Journal Article

Isotopic Determination of Silver in Picomole Quantities by Surface Ionization Mass Spectrometry

Abstract

A microanalytical procedure is described for the quantitative separation of Ag from natural samples by anion exchange and analysis by surface ionization mass spectrometry using silica gel as an emitter. The isotopic composition of 50 pmol of Ag can be measured on a Faraday detector with a precision of 0.1%. Isotopic measurements have been made on as little as 0.15 pmol with a precision of 1% using an electron multiplier detector. The total procedural blank for the anion exchange Separation is 0.15 pmol. Using stable isotope dilution 0.5 pmol of Ag, which Is 3 X 10^(11) atoms, can be measured with a precision of better than 1% with only a 30% blank correction. This allows the accurate determination of Ag in natural samples down to concentration levels of 1 pmol per gram. The ionization efficiency for Ag is about 1-2% and the detection limit is 1 fmol. This procedure has been applied to several meteorites, and a standard terrestrial rock.

Additional Information

© 1978 American Chemical Society. Received for review October 17, 1977. Accepted May 2, 1978. W.R.K. was supported by NASA Grant NSG 7040 while a Visiting Associate in Geochemistry at the California Institute of Technology. General support for the Lunatic Asylum laboratory is provided by NSF Grant PHY 76-83685 and NASA Grant NGL 05-002-188. This is Contribution No. 2980 (254) of the Division of Geological and Planetary Sciences. This project was conceived by John W. Larimer of Arizona State University and the authors and was carried out as a joint study between ASU and the California Institute of Technology. We are pleased that both institutions allowed communal use of resources. The advice and encouragement of John W. Larimer was greatly appreciated. The encouragement and assistance of colleagues D. A. Papanastassiou and Felix Oberli is acknowledged.

Additional details

Created:
August 19, 2023
Modified:
October 25, 2023