The Effect of Matrix Interferences on In Situ Boron Isotope Analysis by Laser Ablation MC-ICP-MS
Abstract
Boron isotope analysis is a key geochemical tool for understanding Earth-based processes, with applications ranging from a palaeo-pH proxy for seawater in studies concerned with ocean acidification to a tracer for mixing processes in studies of the ocean-crust-mantle system. Laser ablation multi-collector inductively-coupled-plasma mass spectrometry (LA-MC-ICP-MS) allows the in situ collection of geochemical information at high spatial resolutions, with the added benefit of high sample through-put. However, despite clear advantages over traditional methods, the adoption of laser ablation techniques to studies concerning boron isotopes has not been straight forward, with numerous authors reporting significant levels of inaccuracy (up to 6 ‰ Δδ11B) and imprecision (typically 1-2 ‰ δ11B) compared to other analytical techniques [1, 2].
Here we explore the role of matrix interferences on boron isotope analysis by LA-MC-ICP-MS and present a protocol for obtaining accurate δ11B data following mass bias correction with the universal NIST glass standard SRM610. Our protocol enables small-scale investigations of boron isotope heterogeneities in a range of samples without the need for closely matrix-matched standards, which are themselves often difficult to obtain and/or characterise. Our methods will be demonstrated through timeseries analysis of a section of a Siderastrea siderea core collected from the Southern Belize portion of the Mesoamerican Barrier Reef System. [1] Mikova et al. (2014) J. Anal. Atom. Spectrom. 29, 903-914. [2] Thil et al. (2016) Rapid Commun. Mass Sp. 30, 359-371.- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.V43A..05S
- Keywords:
-
- 1040 Radiogenic isotope geochemistry;
- GEOCHEMISTRYDE: 1041 Stable isotope geochemistry;
- GEOCHEMISTRYDE: 1094 Instruments and techniques;
- GEOCHEMISTRYDE: 1194 Instruments and techniques;
- GEOCHRONOLOGY