Grantee Research Project Results
Final Report: Novel Detection Interface for Gas Chromatography/Fourier Transform Infrared Spectroscopic Analysis
EPA Contract Number: 68D01042Title: Novel Detection Interface for Gas Chromatography/Fourier Transform Infrared Spectroscopic Analysis
Investigators: Micheels, Ronald H.
Small Business: Polestar Technologies Inc.
EPA Contact:
Phase: I
Project Period: April 1, 2001 through September 1, 2001
Project Amount: $69,985
RFA: Small Business Innovation Research (SBIR) - Phase I (2001) RFA Text | Recipients Lists
Research Category: Ecological Indicators/Assessment/Restoration , SBIR - Monitoring , Small Business Innovation Research (SBIR)
Description:
This Phase I SBIR project was directed at developing a novel infrared detection interface for the hyphenated gas chromatography/Fourier transform infrared (GC/FTIR) spectroscopy analysis technique, to be incorporated into a field-portable GC/FTIR instrument in a Phase II project. The new GC/FTIR interface design has advantages over the conventional infrared light pipe GC/FTIR interface, with reduced cost, greater portability, and potentially improved detection sensitivity. Currently, GC/FTIR analysis is used less frequently than gas chromatography/mass spectrometry because of the higher instrument costs and reduced sensitivity of GC/FTIR, even though this infrared detection technique provides better identification of chemical isomers and can handle much higher analyte concentrations without sample dilution. Portable GC/FTIR instruments have not yet been developed, primarily because the GC/FTIR interfaces currently employed are based on a light pipe gas cell combined with a liquid nitrogen-cooled HgCdTe detector. Because of the size of the light pipe interface and the detector cooling requirements, these light pipe GC/FTIR interfaces are not very amenable to field-portable use.Summary/Accomplishments (Outputs/Outcomes):
Polestar Technologies, Inc., constructed and evaluated the innovative GC/FTIR interface during the Phase I project with known gas samples containing known concentrations of CO2 and toluene. The results of the evaluation indicated that the interface had promise as an FTIR detection and sampling system with lower cost and greatly reduced size relative to existing FTIR detection and sampling systems of related design. However, the Phase I prototype device did not have a sufficient combination of response time and sensitivity to be successful for use as a GC/FTIR interface. The detection/sampling system demonstrated a detection sensitivity for toluene in He of about 500 ppm for an average of 100 spectral scans with a total collection/Fourier-transform processing time of about 60 seconds. FTIR detection for a capillary GC system requires gas phase detection sensitivities of at least 25 ppm (volume) with a spectral collection time of less than 3 seconds. Use of the new device as a GC/FTIR interface may be possible with further optimization of the device together with optimization of the FTIR infrared source and beam-delivery optics.Commercial applications outside of GC/FTIR are being pursued for the innovative FTIR detection/sampling system developed in the Phase I project. The FTIR detection/sampling system will find applications in analysis of very small samples with volumes of less than 70 L for forensic analysis and for the analysis of gases and air samples for trace constituents where spectral collection times of 1?2 minutes can be used. The new detection/sampling device employs parts that are very low cost and compact, which gives the system a competitive advantage over other FTIR detection/sampling systems that can be used for the same type of samples. A patent application was filed in July 2001, for the design and method of the new FTIR detection/sampling system and its use as a GC/FTIR interface.
Conclusions:
The prototype innovative FTIR detection/sampling device developed in the Phase I project did not have sufficient sensitivity and response time for successful application as a GC/FTIR interface, but it did show promise as an FTIR detection/sampling system with lower cost and greatly reduced size relative to existing FTIR sampling systems of related design. Commercialization of the device developed in the Phase I project is being pursued for the latter application, where the device has advantages in cost and ability to handle small samples.Supplemental Keywords:
FTIR, sampling/detection, forensic analysis., RFA, Scientific Discipline, Toxics, Air, Ecosystem Protection/Environmental Exposure & Risk, Chemical Engineering, Environmental Chemistry, VOCs, Analytical Chemistry, Monitoring/Modeling, Chemistry and Materials Science, Environmental Engineering, Engineering, Chemistry, & Physics, environmental monitoring, Field Fourier Infrared (FT-IR), analysis of air and water samples, Fourier Transform Infrared measurement, field portable monitoring, field portable systems, mass spectrometry, detection interface, detection system, gas chromatography, chemical detection techniques, field monitoring, field deployable, field detection, spectroscopic, Volatile Organic Compounds (VOCs), air quality field measurements, aerosol analyzers, air quality, atmospheric chemistry, Fourier transform infraredThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.