Neodymium isotope analyses after combined extraction of actinide and lanthanide elements from seawater and deep-sea coral aragonite
File(s)Struve et al., accepted, G-cubed methods.pdf (918.53 KB)
Accepted version
Author(s)
Type
Journal Article
Abstract
Isotopes of the actinide elements protactinium (Pa), thorium (Th) and uranium (U), and the lanthanide element neodymium (Nd) are often used as complementary tracers of modern and past oceanic processes. The extraction of such elements from low abundance matrices, such as seawater and carbonate, is however labor-intensive and requires significant amounts of sample material. We here present a combined method for the extraction of Pa, Th and Nd from 5 to 10 L seawater samples, and of U, Th and Nd from <1 g carbonate samples. Neodymium is collected in the respective wash fractions of Pa-Th and U-Th anion exchange chromatographies. Regardless of the original sample matrix, Nd is extracted during a two-stage ion chromatography, followed by thermal ionization mass spectrometry (TIMS) analysis as NdO+. Using this combined procedure, we obtained results for Nd isotopic compositions on two GEOTRACES consensus samples from Bermuda Atlantic Time Series (BATS), which are within error identical to results for separately sampled and processed dedicated Nd samples (εNd = -9.20 ± 0.21 and -13.11 ± 0.21 for 15 and 2000 m water depths, respectively; intercalibration results from 14 laboratories: εNd = -9.19 ± 0.57 and -13.14 ± 0.57). Furthermore, Nd isotope results for an in-house coral reference material are identical within analytical uncertainty for dedicated Nd chemistry and after collection of Nd from U-Th anion exchange chromatography. Our procedure does not require major adaptations to independently used ion exchange chromatographies for U-Pa-Th and Nd, and can hence be readily implemented for a wide range of applications.
Date Issued
2016-01-09
Date Acceptance
2015-12-07
Citation
Geochemistry Geophysics Geosystems, 2016, 17 (1), pp.232-240
ISSN
1525-2027
Publisher
American Geophysical Union (AGU)
Start Page
232
End Page
240
Journal / Book Title
Geochemistry Geophysics Geosystems
Volume
17
Issue
1
Copyright Statement
This is the peer reviewed version of the following article: Struve, T., et al. (2016), Neodymium isotope analyses after combined extraction of actinide and lanthanide elements from seawater and deep-sea coral aragonite, Geochem. Geophys. Geosyst., 17, 232–240, which has been published in final form at https://dx.doi.org/10.1002/2015GC006130. This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving.
Sponsor
The Leverhulme Trust
Natural Environment Research Council (NERC)
Natural Environment Research Council (NERC)
Grant Number
RPG-398
NE/J021636/1
NE/N001141/1
Subjects
Science & Technology
Physical Sciences
Geochemistry & Geophysics
deep-sea corals
seawater
GEOTRACES
extraction methods
neodymium isotopes
GEOTRACES INTERCALIBRATION
LAST DEGLACIATION
ANION-EXCHANGE
NITRIC ACID
SEPARATION
PALEOCEANOGRAPHY
CHROMATOGRAPHY
RADIOCARBON
CATIONS
THORIUM
04 Earth Sciences
02 Physical Sciences
Publication Status
Published
Date Publish Online
2015-12-14