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Laser ablation mass spectrometry blast through detection in R
  • +2
  • Alex Searle-Barnes,
  • Andy Milton,
  • Christopher Standish,
  • Gavin Foster,
  • Thomas Ezard
Alex Searle-Barnes
University of Southampton

Corresponding Author:[email protected]

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Andy Milton
University of Southampton
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Christopher Standish
University of Southampton
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Gavin Foster
University of Southampton
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Thomas Ezard
University of Southampton
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Abstract

Rational: Organisms that grow a hard carbonate shell or skeleton, such as foraminifera, corals or molluscs, incorporate trace elements into their shell during growth that absorbs the environmental change and biological activity they experienced. These geochemical signals locked within the carbonate are archives used in proxy reconstructions to study past environments and climates, to decipher taxonomy of cryptic species and to resolve evolutionary responses to climatic changes. Methods: Here we use a laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) as a time resolved acquisition to quantify the elemental composition of carbonate shells. We present the LABLASTER (Laser Ablation BLASt Through Endpoint in R) package, which imports a single time resolved LA-ICP-MS analysis, then detects when the laser has ablated through the carbonate as a function of change in signal over time, and outputs key summary statistics. We provide two worked examples within the package: a planktic foraminifera and a tropical coral. Results: We present the first R package that improves signal: noise ratios in data reduction workflows by automating the detection of when the laser has ablated through a sample using a smoothed time-series and subsequent removal of off-target data points. The functions are flexible and adjust dynamically to enhance the signal: noise ratio of the desired geochemical target. Visualisation tools for manual validation are also included. Conclusions: LABLASTER increases transparency and repeatability by algorithmically identifying when the laser has either ablated fully through a sample or across a mineral boundary and is thus no longer documenting a geochemical signal associated with the desired sample. LABLASTER’s focus on better data targeting means more accurate extraction of biological and geochemical signals.
10 Mar 2023Submitted to Rapid Communications in Mass Spectrometry
11 Mar 2023Submission Checks Completed
11 Mar 2023Assigned to Editor
11 Mar 2023Review(s) Completed, Editorial Evaluation Pending
11 Mar 2023Reviewer(s) Assigned
06 Apr 2023Editorial Decision: Revise Minor
28 Apr 20231st Revision Received
28 Apr 2023Submission Checks Completed
28 Apr 2023Assigned to Editor
28 Apr 2023Review(s) Completed, Editorial Evaluation Pending
28 Apr 2023Editorial Decision: Accept