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Relative molar response factors for thermal conductivity detectors
Journal of Chromatographic Science
|March 7, 2000
Summary
Relative molar response factors for thermal conductivity detectors are not universal. Calibration using literature values may lead to significant errors in measured concentrations, highlighting instrument-specific variations.
Area of Science:
- Analytical Chemistry
- Chromatography
Background:
- Relative molar response factors (RMRFs) are crucial for accurate quantitative analysis using gas chromatography (GC).
- Previous literature suggested RMRFs for thermal conductivity detectors (TCDs) are independent of the specific instrument used.
Purpose of the Study:
- To investigate the universality of RMRFs for TCDs across different GC instruments.
- To determine if RMRFs exhibit instrument-dependent variations.
Main Methods:
- Measured RMRFs for homologous series on multiple GC systems equipped with TCDs.
- Compared experimental RMRF values with existing literature data.
Main Results:
- Observed a linear relationship between RMRFs and carbon number in homologous series on a single instrument.
- Identified significant instrument-dependent variations in the slope of this linear relationship.
- Contradicted prior findings of instrument independence for RMRFs.
Conclusions:
- RMRFs for TCDs are not universal and show significant instrument-specific differences.
- Relying on literature RMRF values for TCD calibration can introduce substantial errors in concentration measurements.
- Instrument-specific calibration is essential for accurate quantitative analysis with TCDs.