Periodic Reporting for period 1 - EVOQUE (Enhanced selectivity VOC detection using novel GC-QEPAS)
Berichtszeitraum: 2024-01-01 bis 2025-06-30
Volatile organic compounds (VOCs) are organic chemicals that have a high vapor pressure at room temperature. Based on their origin and formation mechanisms, VOCs can be markers in many industrial processes; in food production as quality markers, technological indicators, process contaminants; in plant phenotyping as botanical/geographical tracers, authenticity markers; and in crops storage as shelf-life indicators. VOCs also pose a range of hazards to human health and the environment.
EVOQUE’s main objective is to develop a novel photonic-based detection system with potential to outperform the current standards and to meet the challenging requirements of at-line, on-line & in-field needs of Agriculture, Food, Environmental Pollution monitoring and Industrial Emissions monitoring.
EVOQUE will combine gas chromatography (GC), Quartz Enhanced Photo-Acoustic Spectroscopy (QEPAS), long wavelength quantum cascade lasers (QCLs) and mid-IR metasurfaces to produce a compact, easy to use, low cost, at-line and ultimately online, field deployable VOCs analyser that will have comparable performance to the gold standard lab-based GC-MS. EVOQUE will leverage GC’s separation of components from complex mixtures, and QEPAS’s high sensitivity, specificity and quantification accuracy. Unlike simpler GC detectors, QEPAS will provide molecular recognition based on the specific spectral features of single VOCs. The system measures the target compound even in the presence of interferents, thus avoiding issues with poor repeatability of elution times and reducing the false positive rate relative to GC with non-specific detectors. Also, optical spectroscopy of many VOCs is hampered by absorption by atmospheric compounds at the wavelengths of interest or overlapping absorption features of related molecules; using the GC column, these compounds are separated and eluted from the column at different times, thus unleashing the potential of photonics for sensitive fast, non-destructive measurements of VOCs.
EVOQUE’s main objective is to develop a novel photonic-based detection system with potential to outperform the current standards and to meet the challenging requirements of at-line, on-line & in-field needs of Agriculture, Food, Environmental Pollution monitoring and Industrial Emissions monitoring.
EVOQUE will combine gas chromatography (GC), Quartz Enhanced Photo-Acoustic Spectroscopy (QEPAS), long wavelength quantum cascade lasers (QCLs) and mid-IR metasurfaces to produce a compact, easy to use, low cost, at-line and ultimately online, field deployable VOCs analyser that will have comparable performance to the gold standard lab-based GC-MS. EVOQUE will leverage GC’s separation of components from complex mixtures, and QEPAS’s high sensitivity, specificity and quantification accuracy. Unlike simpler GC detectors, QEPAS will provide molecular recognition based on the specific spectral features of single VOCs. The system measures the target compound even in the presence of interferents, thus avoiding issues with poor repeatability of elution times and reducing the false positive rate relative to GC with non-specific detectors. Also, optical spectroscopy of many VOCs is hampered by absorption by atmospheric compounds at the wavelengths of interest or overlapping absorption features of related molecules; using the GC column, these compounds are separated and eluted from the column at different times, thus unleashing the potential of photonics for sensitive fast, non-destructive measurements of VOCs.
EVOQUE aims to develop a new Gas Chromatography Quartz Enhanced Photo-Acoustic Spectroscopy VOC analyser. The analyser is built up of different modules, namely the GC module, QEPAS module, laser module etc. The work plan is designed so that different generations and modules (particularly lasers) will be developed.
This began with the preparation of a “technical reference manual” (TRM), which performs a key role in aligning the form factors, electrical and optical connections, firmware, protocols, target compounds etc. The TRM is a maintained as a living document, to guide the Work Packages (WPs) in the development of their respective modules.
In the first Reporting Period, WP2 has collected IR absorption spectra of VOCs of interest for EVOQUE, expanding commonly available spectral databases such as those provided by HITRAN, NIST, and PNNL. WP3 has produced the first generation of Quantum Cascade (QCL) and Interband Cascade (ICL) Lasers tailored for the EVOQUE system’s gas detection needs, i.e. targeting specific characteristic wavelengths. Work has also begun on the design and fabrication of metalenses for precision focusing and beam shaping of the laser output. WP4 has developed the first generation of the EVOQUE Acoustic Detection Module (ADM) for QEPAS, and made initial tests in combining this with a Gas Chromatography (GC) system. WP5 investigated the GC columns best suited for the EVOQUE system, and developed the optimal coupling system between GC and QEPAS. WP6 then focused on the integration of the overall analyser, including control electronics and Graphical User Interface.
This began with the preparation of a “technical reference manual” (TRM), which performs a key role in aligning the form factors, electrical and optical connections, firmware, protocols, target compounds etc. The TRM is a maintained as a living document, to guide the Work Packages (WPs) in the development of their respective modules.
In the first Reporting Period, WP2 has collected IR absorption spectra of VOCs of interest for EVOQUE, expanding commonly available spectral databases such as those provided by HITRAN, NIST, and PNNL. WP3 has produced the first generation of Quantum Cascade (QCL) and Interband Cascade (ICL) Lasers tailored for the EVOQUE system’s gas detection needs, i.e. targeting specific characteristic wavelengths. Work has also begun on the design and fabrication of metalenses for precision focusing and beam shaping of the laser output. WP4 has developed the first generation of the EVOQUE Acoustic Detection Module (ADM) for QEPAS, and made initial tests in combining this with a Gas Chromatography (GC) system. WP5 investigated the GC columns best suited for the EVOQUE system, and developed the optimal coupling system between GC and QEPAS. WP6 then focused on the integration of the overall analyser, including control electronics and Graphical User Interface.
The project has successfully demonstrated the first integrated gas chromatography and quartz-enhanced photoacoustic spectroscopy (GC-QEPAS) analyser capable of detecting key volatile organic compounds (VOCs) like propane at sub-ppm levels in benchtop trials. This proof-of-concept validates that EVOQUE’s combined system can match lab-grade sensitivity but in a compact, deployable format.
The project has developed and optimised novel miniaturised acoustic detection modules (ADMs) that drastically reduce internal volume and dead-volume, allowing better chromatographic resolution and sharper detection peaks even at low flow rates. This engineering step is vital for portable, high-fidelity VOC analysis on-site.
EVOQUE has expanded high-resolution mid-IR spectra for several important VOCs (aldehydes, pyrazines, furans) well beyond what is available in standard databases. This spectral data directly supports improved selectivity and accuracy of the new photonic sensors and feeds into new machine learning models for product fingerprinting, such as roasted coffee origin validation. Efforts are underway to ensure this data is made publicly accessible, via e.g. HITRAN or NIST.
Finally, a real prototype of the EVOQUE system has been integrated with new custom laser sources, and its electronics have been validated in fully functional end-to-end tests. This demonstrates that all subsystems—GC column, preconcentrator, QEPAS sensor, and control electronics—are progressing from separate lab modules to a unified portable device suitable for industrial deployment in sectors like food quality monitoring and environmental emissions control, laying the groundwork for the second phase of the project.
The project has developed and optimised novel miniaturised acoustic detection modules (ADMs) that drastically reduce internal volume and dead-volume, allowing better chromatographic resolution and sharper detection peaks even at low flow rates. This engineering step is vital for portable, high-fidelity VOC analysis on-site.
EVOQUE has expanded high-resolution mid-IR spectra for several important VOCs (aldehydes, pyrazines, furans) well beyond what is available in standard databases. This spectral data directly supports improved selectivity and accuracy of the new photonic sensors and feeds into new machine learning models for product fingerprinting, such as roasted coffee origin validation. Efforts are underway to ensure this data is made publicly accessible, via e.g. HITRAN or NIST.
Finally, a real prototype of the EVOQUE system has been integrated with new custom laser sources, and its electronics have been validated in fully functional end-to-end tests. This demonstrates that all subsystems—GC column, preconcentrator, QEPAS sensor, and control electronics—are progressing from separate lab modules to a unified portable device suitable for industrial deployment in sectors like food quality monitoring and environmental emissions control, laying the groundwork for the second phase of the project.