How Much Can We Trust Major Element Quantification in Bioapatite Investigation?

Area of Science:

• Geochemistry
• Paleontology
• Analytical Chemistry

Background:

• Bioapatite composition is crucial for vertebrate evolution and serves as an archive of environmental information.
• Standard analytical methods for bioapatite composition require internal standards, but bioapatite's variable nature complicates this.
• Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICPMS) is a powerful tool for analyzing solid samples like bioapatite.

Purpose of the Study:

• To develop and validate a method for accurate major element concentration measurement in bioapatite using LA-ICPMS.
• To address the challenge of identifying a sole internal standard for bioapatite analysis due to its compositional variability.
• To establish the necessity of matrix-matched external calibration standards for reliable bioapatite chemical characterization.

Main Methods:

• Development of homemade matrix-matched external calibration standards.
• Application of LA-ICPMS for measuring major elements (P, Ca, Mg, Na, K, Si, Al, Fe) in bioapatite.
• Testing and validation using living and fossil shark teeth, with comparisons to other analytical techniques and certified standards.

Main Results:

• The proposed method using matrix-matched external calibration standards provides reliable quantification of major elements in bioapatite.
• Comparison with other techniques and standards confirmed the accuracy and necessity of the developed method.
• Variability factors like matrix aggregation, volatile compounds, fossilization, and instrumental drift were identified as further challenges.

Conclusions:

• Matrix-matched calibration is mandatory for accurate LA-ICPMS analysis of bioapatite major elements.
• This approach enables reliable chemical characterization of bioapatite, vital for understanding vertebrate evolution and paleoenvironmental conditions.
• Further research is needed to account for additional variability parameters in bioapatite analysis.