ATR Infrared Technique Quantifies Aragonite Carbonate Mixtures

A team led by Mahmoud Alkhatib, Nabil Thabteh, Fuad Al-Rimawi, and Mutaz Qutob published a new analytical approach in Eur. J. Mineral., 38, 557–565 (2026) that uses attenuated total reflection Fourier transform infrared spectroscopy (ATR‑FTIR) to quantify components within aragonite-group carbonates without any sample preparation. The technique offers a rapid alternative to X-ray diffraction for qualitative and quantitative analysis of these minerals.¹

The study focuses on synthetic mixtures of aragonite containing the carbonate phases strontianite and witherite. By developing calibration curves based on absorbance ratios between characteristic peaks, the authors reduced variability caused by measurement conditions and achieved more accurate quantification of each phase in mixed samples. This advance is significant because traditional methods often require laborious sample prep or are less precise when distinguishing closely related carbonate species.¹

Beyond the specific application to aragonite, the research demonstrates how ATR‑FTIR can be adapted to other mineral systems where surface-sensitive measurements are advantageous. The method’s ability to probe molecular vibrations directly from the material’s surface makes it broadly useful across chemistry, physics, and geology, especially when quick screening is needed.¹

Expert context explains that ATR works by reflecting light off a material’s surface at varying angles, allowing scientists to observe vibrational modes of molecules inside the sample. In this case, the ATR approach enabled direct assessment of strontianite and witherite concentrations in aragonite mixtures, providing a practical tool for studying sedimentary carbonates.¹