P 13 - “The Potential of GC-FTIR and IR Libraries to resolve unknown”
P 13 - “The Potential of GC-FTIR and IR Libraries to resolve unknown”
The coupling of gas chromatography (GC) with Fourier-transform infrared spectroscopy (FTIR) provides an analytical platform capable of combining separation information and structure elucidation. GC-FTIR offers direct information on functional groups and molecular geometry, allowing differentiation of isomers or isobaric molecules that possess identical mass spectra. Advances in technology, including the development of new interfaces, such as the solid deposition (-sd), have improved sensitivity and spectral resolution, enabling reliable identification of trace components in complex matrices.
A critical factor for the performance of GC-FTIR is the use of dedicated infrared spectral libraries precisely acquired. These databases enable automated recognition and spectral matching, facilitating rapid and confident identification of compounds. For instance, GC-FTIR allows the identification of hydrocarbons based on characteristic IR bands, allowing differentiation among alkanes, alkenes, cycloalkanes, and aromatics that often produce indistinguishable mass spectra.
This presentation highlights recent applications of GC-FTIR combined with IR databases for the discrimination of structural isomers and the identification of hydrocarbons, demonstrating its growing relevance as a complementary tool to GC-MS in modern separation science. In this research, effort has been devoted to the development of a dedicated IR spectral database, comprising hundreds of hydrocarbon components registered with sd-GC-FTIR instruments under standardized conditions (e.g. disc speed, temperature, sample amount delivered), to ensure spectral reproducibility and reliability. This comprehensive library forms the basis for robust automated spectral matching and supports the identification process.