Open AccessAbsolute Ca Isotopic Measurement Using an Improved Double Spike Technique
Author(s) -
Jason Jiun-San Shen,
Der-Chuen Lee,
WenTzong Liang
Publication year - 2009
Publication title -
terrestrial, atmospheric and oceanic sciences/terrestrial, atmospheric, and oceanic sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.35
H-Index - 46
eISSN - 2223-8964
pISSN - 1017-0839
DOI - 10.3319/tao.2008.05.30.01(tt
Subject(s) - spike (software development) , absolute (philosophy) , mathematics , statistics , geology , computer science , philosophy , software engineering , epistemology
[[abstract]]A new vector analytical method has been developed in order to obtain the true isotopic composition of the (42)Ca-(48)Ca double spike. This is achieved by using two different sample-spike mixtures combined with the double spike and natural Ca data. Because the natural sample (two mixtures) and the spike should all lie on a single mixing line, we are able to constrain the true isotopic composition of our double spike using this new approach. Once the isotopic composition of the Ca double spike is established, we are able to obtain the true Ca isotopic composition of the NIST Ca standard SRM915a, (40)Ca/(44)Ca = 46.537 +/- 2 (2 sigma(m), n = 55), (42)Ca/(44)Ca = 0.31031 +/- 1, (43)Ca/(44)Ca = 0.06474 +/- 1, and (48)Ca/(44)Ca = 0.08956 +/- 1. Despite an offset of 1.3% in (40)Ca/(44)Ca between our result and the previously reported value (Russell et al. 1978), Our data indicate all offset of 1.89 parts per thousand in (40)Ca/(44)Ca between SRM915a and seawater, entirely consistent with the published results.[[fileno]]2010101010043[[department]]物理