VOLTINT: A Matlab®-based program for semi-automated processing of geochemical data acquired by voltammetry

Recent progress has resulted in the development of advanced techniques to acquire geochemical information in situ in aquatic systems. Among these techniques, voltammetry has generated significant interest for its ability to detect several important redox-sensitive chemical species in a fast, reliable, and automated manner. Many research groups worldwide have now adopted these techniques for geochemical measurements in various marine and freshwater systems, including water column, sediment, microbial mat, and groundwater, with a high spatial and temporal resolution. Unfortunately, the ability to conduct multiple measurements with great spatial and temporal resolutions generates large data sets that are difficult to integrate manually. We report a new computer program, voltammetric integration software (VOLTINT), that can integrate large voltammetric data sets semi-automatically. This program implemented in Matlab® is based on a graphical user interface to visualize and identify voltammetric signals. The program differentiates between voltammetric techniques and derives or integrates voltammetric signals to produce output data files containing the redox potentials, current intensities, and, when appropriate, peak surface areas of each electrochemical species that can be detected. VOLTINT was developed with the intention of integrating voltammetric data obtained with potentiostats from a specific company Analytical Instrument Systems, Inc. (AIS). However, the scripts can be easily altered to process any ASCII file containing voltammetric data. The details of the program are presented, and examples provided along with recommendations regarding the analysis of voltammetric data in the context of this program. VOLTINT is available free of charge to anyone who is interested in integrating multiple voltammetric data files in a fast and reliable manner.