BARCHAN: Blob Alignment for Robust CHromatographic ANalysis

- BARCHAN: 2D chromatogram and template alignment based on peak registration.
- The alignment is performed by probabilistic estimation with a Gaussian Mixture Model.
- It combines a rigid and a non-rigid transformation for complex samples analysis.
- The method accounts for noise, outliers and missing peaks in an automated way.
- BARCHAN significantly reduces the time to results for GC × GC analysis.

Two-dimensional gas chromatography (GC × GC) plays a central role into the elucidation of complex samples. The automation of the identification of peak areas is of prime interest to obtain a fast and repeatable analysis of chromatograms. To determine the concentration of compounds or pseudo-compounds, templates of blobs are defined and superimposed on a reference chromatogram. The templates then need to be modified when different chromatograms are recorded. In this study, we present a chromatogram and template alignment method based on peak registration called BARCHAN. Peaks are identified using a robust mathematical morphology tool. The alignment is performed by a probabilistic estimation of a rigid transformation along the first dimension, and a non-rigid transformation in the second dimension, taking into account noise, outliers and missing peaks in a fully automated way. Resulting aligned chromatograms and masks are presented on two datasets. The proposed algorithm proves to be fast and reliable. It significantly reduces the time to results for GC × GC analysis.