Improved Chromatographic Alignment of GC-IMS Data Using Spectral Information.
4 affiliations
- 1Department of Electronics and Biomedical Engineering, Universitat de Barcelona, 08028 Barcelona, Spain.
- 2Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, 08028 Barcelona, Spain.
- 3Institut d'Oncologia de la Catalunya Sud (IOCS), Hospital Universitari Sant Joan de Reus, Facultat de Medicina i Ciències de la Salut, Universitat Rovira i Virgili, 43204 Reus, Spain.
- 4Institut de Recerca Biomèdica Catalunya Sud (IRBCatSud), 43204 Reus, Spain.
Abstract
Gas chromatography-ion mobility spectrometry (GC-IMS) provides two-dimensional separation of volatile compounds, but instrumental variability can produce shifts and nonlinear distortions that hinder comparison among measurements. This study presents a chromatographic alignment workflow that uses spectral information from the drift-time dimension to support peak correspondence. The method combines injection point correction and parametric time warping along the retention-time axis with multiplicative correction of the drift-time axis. Peaks are then matched using information from both dimensions, and their retention positions are used as internal landmarks for a final cubic spline refinement without requiring standards specifically for alignment. The workflow was evaluated using 134 repeated measurements of a pooled urine sample and compared with correlation optimized warping (COW) applied directly and after different preprocessing stages. Conventional metrics based on correlation, Euclidean similarity, simplicity, and peak factor indicated comparable global performance for the proposed method and the best COW workflows. However, a correspondence-based assessment showed that high profile similarity and low positional dispersion did not necessarily imply preservation of the same peak correspondences. Direct COW recovered 45.2% of the reference correspondences, whereas recovery increased to 85.0% after injection point correction and to 89.9% after injection point correction plus parametric time warping. These results highlight the importance of combining profile-based metrics with measures of peak correspondence and show how the orthogonal drift-time dimension can provide additional constraints for chromatographic alignment in GC-IMS data.
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BibTeX
@article{fernandez2026improved,
title = {{Improved Chromatographic Alignment of GC-IMS Data Using Spectral Information.}},
author = {Luis Fernández and Gema Guedes de la Cruz and Eduardo Caballero and Eva Martín-López and Albert Vidal and Javier Alonso-Valdesueiro and Josep Gumà and Raquel Cumeras and Antonio Pardo and Santiago Marco},
journal = {ACS measurement science au},
year = {2026},
month = oct,
doi = {10.1021/acsmeasuresciau.6c00271},
url = {https://europepmc.org/article/MED/42921132},
note = {CC BY},
}
RIS
TY - JOUR
TI - Improved Chromatographic Alignment of GC-IMS Data Using Spectral Information.
AU - Luis Fernández
AU - Gema Guedes de la Cruz
AU - Eduardo Caballero
AU - Eva Martín-López
AU - Albert Vidal
AU - Javier Alonso-Valdesueiro
AU - Josep Gumà
AU - Raquel Cumeras
AU - Antonio Pardo
AU - Santiago Marco
PY - 2026
DA - 2026/10/02
JO - ACS measurement science au
DO - 10.1021/acsmeasuresciau.6c00271
UR - https://europepmc.org/article/MED/42921132
AB - Gas chromatography-ion mobility spectrometry (GC-IMS) provides two-dimensional separation of volatile compounds, but instrumental variability can produce shifts and nonlinear distortions that hinder comparison among measurements. This study presents a chromatographic alignment workflow that uses spectral information from the drift-time dimension to support peak correspondence. The method combines injection point correction and parametric time warping along the retention-time axis with multiplicative correction of the drift-time axis. Peaks are then matched using information from both dimensions, and their retention positions are used as internal landmarks for a final cubic spline refinement without requiring standards specifically for alignment. The workflow was evaluated using 134 repeated measurements of a pooled urine sample and compared with correlation optimized warping (COW) applied directly and after different preprocessing stages. Conventional metrics based on correlation, Euclidean similarity, simplicity, and peak factor indicated comparable global performance for the proposed method and the best COW workflows. However, a correspondence-based assessment showed that high profile similarity and low positional dispersion did not necessarily imply preservation of the same peak correspondences. Direct COW recovered 45.2% of the reference correspondences, whereas recovery increased to 85.0% after injection point correction and to 89.9% after injection point correction plus parametric time warping. These results highlight the importance of combining profile-based metrics with measures of peak correspondence and show how the orthogonal drift-time dimension can provide additional constraints for chromatographic alignment in GC-IMS data.
SN - 2694-250X
ER -