High resolution minor and trace element measurements for mussel shells using LA-ICP-MS
Abstract
The successively deposited calcium carbonate layers in mollusk shells could offer high resolution archives of the environmental conditions the mollusk has experienced during its life. Previous studies have shown that the elemental composition of mollusk shells is related to environmental parameters. Understanding the high resolution environmental conditions recorded in the mollusk shells requires a reliable high resolution analytical method of the trace and minor element composition in the shells. In this study, we investigated three methods using different instrumental configurations to generate high resolution records/time series of a suite of minor/ trace elements in mussel shells (Mytilus californianus) using laser ablation sector field inductively coupled plasma mass spectrometry (LA-ICP-MS) and compared their advantages and disadvantages. The three methods include running the ablated sample with dry plasma, running the ablated sample with diluted nitric acid blank solution and running the ablated sample with spiked solution. We concluded that running the ablated material with the spiked solution could yield the most reproducible signal and accurate data for Mg/Ca, Sr/Ca, Ba/Ca, La/Ca, Ce/Ca and Nd/Ca. To better understand the features of the laser ablation analytical method, we did a series of tests, such as scanning at different speeds, different directions, and applying different sampling strategies and explored the possible complications that could be encountered in using the laser ablation analytical method. In addition, we compared the results from the micromilled samples analyzed by the solution based method to the those obtained from the laser ablation method. Our results demonstrate that applying the slow ablation speed and simultaneously introducing the spiked solution (i.e. along with the ablated sample in the He carrier gas) could yield high resolution and reproducible time series of element/Ca ratios throughout the life span of the mussel. An exciting result is that seasonal and annual variations could be observed in some of the element/Ca ratios from this laser method. However, for some elements with very low concentration, like Cd and U, more reproducible and higher precision results are acquired using solution based analytical method.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2011
- Bibcode:
- 2011AGUFMOS31A1611B
- Keywords:
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- 1094 GEOCHEMISTRY / Instruments and techniques;
- 4875 OCEANOGRAPHY: BIOLOGICAL AND CHEMICAL / Trace elements