RATIONALE: The absence of an agreed-upon δ(17)O value for the primary reference water SLAP leads to significant discrepancies in the reported values of δ(17)O and the parameter (17)O(excess). The accuracy of δ(17)O and (17)O(excess) values is significantly improved if the measurements are normalized using a two-point calibration, following the convention for δ(2)H and δ(18)O values. METHODS: New measurements of the δ(17)O values of SLAP2 and GISP are presented and compared with published data. Water samples were fluorinated with CoF(3). Helium carried the O(2) product to a 5A (4.2 to 4.4 Å) molecular sieve trap submerged in liquid nitrogen. The O(2) sample was introduced into a dual-inlet ThermoFinnigan MAT 253 isotope ratio mass spectrometer for measurement of m/z 32, 33, and 34. The δ(18)O and δ(17) values were calculated after 90 comparisons with an O(2) reference gas. RESULTS: We propose that the accepted δ(17)O value of SLAP be defined in terms of δ(18) O = -55.5 ‰ and (17)O(excess) = 0, yielding a δ(17)O value of approximately -29.6986 ‰ [corrected]. Using this definition for SLAP and the recommended normalization procedure, the δ(17)O value of GISP is -13.16 ± 0.05 ‰ and the (17)O(excess) value of GISP is 22 ± 11 per meg. Correcting previous published values of GISP δ(17)O to both VSMOW and SLAP improves the inter-laboratory precision by about 10 per meg. CONCLUSIONS: The data generated here and compiled from previous studies provide a substantial volume of evidence to evaluate the various normalization techniques currently used for triple oxygen isotope measurements. We recommend that reported δ(17) O and (17)O(excess) values be normalized to the VSMOW-SLAP scale, using a definition of SLAP such that its (17)O(excess) is exactly zero.
RATIONALE: The absence of an agreed-upon δ(17)O value for the primary reference waterSLAP leads to significant discrepancies in the reported values of δ(17)O and the parameter (17)O(excess). The accuracy of δ(17)O and (17)O(excess) values is significantly improved if the measurements are normalized using a two-point calibration, following the convention for δ(2)H and δ(18)O values. METHODS: New measurements of the δ(17)O values of SLAP2 and GISP are presented and compared with published data. Water samples were fluorinated with CoF(3). Helium carried the O(2) product to a 5A (4.2 to 4.4 Å) molecular sieve trap submerged in liquid nitrogen. The O(2) sample was introduced into a dual-inlet ThermoFinnigan MAT 253 isotope ratio mass spectrometer for measurement of m/z 32, 33, and 34. The δ(18)O and δ(17) values were calculated after 90 comparisons with an O(2) reference gas. RESULTS: We propose that the accepted δ(17)O value of SLAP be defined in terms of δ(18) O = -55.5 ‰ and (17)O(excess) = 0, yielding a δ(17)O value of approximately -29.6986 ‰ [corrected]. Using this definition for SLAP and the recommended normalization procedure, the δ(17)O value of GISP is -13.16 ± 0.05 ‰ and the (17)O(excess) value of GISP is 22 ± 11 per meg. Correcting previous published values of GISP δ(17)O to both VSMOW and SLAP improves the inter-laboratory precision by about 10 per meg. CONCLUSIONS: The data generated here and compiled from previous studies provide a substantial volume of evidence to evaluate the various normalization techniques currently used for triple oxygen isotope measurements. We recommend that reported δ(17) O and (17)O(excess) values be normalized to the VSMOW-SLAP scale, using a definition of SLAP such that its (17)O(excess) is exactly zero.
Authors: Joseph Galewsky; Hans Christian Steen-Larsen; Robert D Field; John Worden; Camille Risi; Matthias Schneider Journal: Rev Geophys Date: 2016-08-22 Impact factor: 22.000
Authors: Andrew J Christ; Paul R Bierman; Joerg M Schaefer; Dorthe Dahl-Jensen; Jørgen P Steffensen; Lee B Corbett; Dorothy M Peteet; Elizabeth K Thomas; Eric J Steig; Tammy M Rittenour; Jean-Louis Tison; Pierre-Henri Blard; Nicolas Perdrial; David P Dethier; Andrea Lini; Alan J Hidy; Marc W Caffee; John Southon Journal: Proc Natl Acad Sci U S A Date: 2021-03-30 Impact factor: 11.205
Authors: V Faghihi; B M A A Verstappen-Dumoulin; H G Jansen; G van Dijk; A T Aerts-Bijma; E R T Kerstel; M Gröning; H A J Meijer Journal: Rapid Commun Mass Spectrom Date: 2015-02-28 Impact factor: 2.419
Authors: Fernando Gázquez; Ian Mather; James Rolfe; Nicholas P Evans; Daniel Herwartz; Michael Staubwasser; David A Hodell Journal: Rapid Commun Mass Spectrom Date: 2015-11-15 Impact factor: 2.419