A workflow and software solution for spatially resolved spectroscopic and numerical data (SpecXY)

Abstract

Spectroscopic analytical techniques such as Fourier Transform Infrared Spectroscopy (FTIR), Raman or hyperspectral imaging are important in modern geosciences. In recent years there has been a shift from using exclusively single-spot analyses to 2-dimensional maps. Maps help to reveal patterns in a sample that would not be detected by single point measurements. Filtering and extracting signal information from multiple combined pixels can help improve the signal-to-noise ratio and thus the precision of the data. The combination of multi-layer numerical datasets obtained from different instruments or measurement settings opens up the possibility of exploring and investigating individual datasets in much greater detail. However, the amount of data and information in the dataset increases significantly when high-resolution spectroscopic and spatial data is used instead of spot analyses, thus making the data examination and data validation more challenging and time consuming. To investigate large datasets, we have developed SpecXY, a software solution for preparing, editing, extracting, and comparing spatially resolved spectral datasets. SpecXY aims to provide a user-friendly and open-source software solution for working with spectroscopic data by providing a simple user interface that is accessible to all users with basic computer skills. Advanced users with a basic understanding of MATLAB® programming can adapt, customise and extend SpecXY due to its modular and function-based program structure. SpecXY also provides innovative algorithms for analyzing spectral data, such as Monte Carlo deconvolution of peaks, and hybrid classification and filtering based on spectra in combination with user knowledge. Two examples illustrate possible applications of SpecXY: (1) multidimensional classification and correlation of spatially resolved spectroscopic data and quantified chemical element maps, and (2) classification, filtering, quantification of H₂O in minerals and profile extraction of a high-resolution spectroscopic data set measured by Fourier Transform Infrared (FTIR) Spectroscopy coupled to a Focal Plane Array (FPA) detector.