Gas Chromatography-Mass Spectrometry
Gas chromatography-mass spectrometry combines two powerful techniques to provide. Low detection limits are needed for quantitative analysis and compound identification. Gas chromatography-mass spectrometry works with liquid, solid, and gaseous samples.
But is limited to semi-volatile and volatile compounds. In gas chromatography, the sample passes through a glass capillary column coated. With an intermediate gas and is transported by volatilization.
Gas Chromatography Principle and Instrumentation
The stationary phase is connected within the column. And the time it takes for a compound of a particular element. To move through the column to the detector is called the 'retention time'.
These measurements are for identification versus standards. In the MS step of conventional mass spectrometry or gas chromatography-mass spectrometry.
Compounds exiting the GC column are fragmented by electron bombardment. These charged fragments are detected. And the resulting spectrum is used to identify the molecule. Fragmentation patterns are reproducible.
And can be used for quantitative measurements. Gas Chromatography-Mass spectrometry is performed on gases, solids, and liquids. For gases and beverages. Samples are injected gas chromatogram. Solid-state elemental analysis. By degassing or desorption, solvent extraction, or pyrolysis.
Desorption experiments are performed under helium gas flow. At controlled temperatures between 40 and 300 degrees Celsius. Analytes are then collected in a cryotrap during the desorption process.
Sample Chamber: 1.25" x 4" Cylinder. Pyrolysis is another sampling technique for analyzing substances. That cannot be injected into a gas chromatography-mass spectrometer.
This method applies heat to the sample. Resulting in reproducible molecular decomposition. These small molecules are included in the gas chromatogram and analyzed by GC-MS. Probe temperatures up to 1400°C can be used with this method.
Several other sampling methods and sample preparations are available. B. Applications based on species of interest. And sample type, including static headspace analysis, derivatization, and purge. And trap, and solid-phase microextraction.
Strengths Identification of organic components by separating complex mixtures. Quantitative analysis of trace organic impurities low nanograms in solid matrices? Ideal applications Identification and quantification of volatile organic compounds.
In mixtures Gases, Emission studies Residual solvent testing Semiconductor impurity characterization wafers. Other technical products Identification of trace impurities. n liquids or gases Limitations of gas chromatography-mass spectrometry Non-volatile matrices.
Requires extra preparation Evaluation of extractable from plastics. Compounds of interest must be volatile or derivatized. Atmospheric gases are a challenge. Analytical Lab Type A robust analytical tool. That identifies chemicals using time.
It takes for a chemical element to pass through a GC column. Retention time compared to known standards. This is a good technique for simple mixtures or situations. Where the chemicals of interest are known. And calibrated before sample analysis.
