What Is Gas Chromatography-Mass Spectrometry (GC-MS)?
A combination of multiple techniques, GC-MS analysis is particularly useful for identifying and quantifying small, organic molecules in complex mixtures. To enable gas chromatography, samples must be injected directly in the gas phase or transformed to the gas phase via liquid injection, headspace analysis, solid-phase microextraction (SPME), thermal desorption (TD), pyrolysis, evolved gas analysis (EGA) or field desorption (FD), all of which are supported by Covalent’s state-of-the art laboratory.
After exiting the gas chromatograph, compounds must be ionized for analysis and detection. Covalent supports several modes of either hard or soft ionization, including electron ionization, chemical ionization, field ionization, field desorption, and photoionization.
Finally, ions are separated and counted. Depending on the specific application typical mass analyzers include Single Quadrupole (SQ-MS), Triple Quadrupole (TQ-MS) or Time-Of-Flight (ToF) analysis, which allows for significantly improved mass accuracy over quadrupole systems and simplifies the collection of a wide range of m/z without sacrificing sensitivity.
Other Details:
- Seven available injection methods.
- Five available ionization modes.
- Three available mass analyzers including state-of-the-art ToF GC-MS.
- Ideal for all volatile and semi-volatile organic compounds.
Flexibility
Sensitivity
Specificity
Why Use GC-MS?
- Flexible chemical analysis capable of detecting and identifying trace organic molecules.
- Useful for confirming compound identities from other techniques that lack chemical specificity or separation.
- Relevant for a wide range of industries and applications including petrochemical, energy storage, forensics, pharmaceuticals, semiconductors, environmental monitoring, polymer sciences and more.
Analytical Depth
Material Compatibility
Mass Accuracy
How GC-MS Works
Samples injected into a gas chromatographer (GC) are volatilized and swept through a separatory column by an inert carrier gas – usually helium, hydrogen, argon or nitrogen. Compounds separate along the length of the column based on their affinity for the column, and a well-designed method will fully separate all compounds into a mixture. Upon exiting the column, compounds are ionized and transferred to a mass spectrometer (MS), where the generated ions are separated and counted.
Equipment Used for GC-MS
JEOL JMS-T2000 AccuTOF GC-Alpha GC-MS
- Integrated NIST library search software for analyte identification.
- Inert electron ionization source.
- Temperature Range: 150 to 300°C.
- High Sensitivity: Instrument detection limit (IDL) = 18.7 fg.
- Wide Dynamic Range: 4 Orders.
- Wide Mass Range: ~m/z 6,000.
- High Mass Resolving Power: 30,000.
- High Mass Accuracy: to 1 ppm.
Key Differentiators
Strengths
- High sensitivity – order of femtograms.
- Simultaneous detection, identification, and quantification.
- Compatibility with a wide range of sample types.
- Minimal information needed for untargeted analysis.
Limitations
- Requires volatile analytes.
- Analyte-specific calibration required for accurate quantification.
- Significant sample prep may be required.
Example Outputs
Sample Requirements
Gases, liquids and solids are acceptable depending on specific matrix and measurement goals. GC-MS analysis techniques are compatible with small sample volume or mass; measured analyes are typical on the order of nanograms. Analytes must be volatile below 300°C.
GC-MS Applications by Industry
Semiconductor
Critical to identifying yield issues, GC-MS is used in the semiconductor industry to pinpoint sources of yield issues stemming from material purity concerns, monitor the purity of process gas that affects chip quality, and identify organic contaminants to ensure the integrity of cleanroom environments.
Food & Agriculture
GC-MS analysis plays an important role in ensuring the safety of our food supply for manufacturers and regulatory agencies alike. Whether identifying organic residue from pesticide, performing flavor or nutritional analysis, or identifying and eliminating a wide range of contaminants in our food supply, GC-MS plays an essential part in producing the food we eat.
Medical Devices & Biotech
Ranging from medical device chemical characterization to clinical applications for the analysis of bodily fluids, GC-MS plays a critical role in keeping patients healthy, ensuring integrity & fairness in sport, aiding in the treatment of addiction & substance abuse, and aiding in the diagnosis and detection of congenital disease.
Aerospace & Defense
Ensuring the performance of materials under extreme stress in conditions like high temperature or pressure; analysis of critical components in the manufacture of aircraft and engine components; the forensic analysis of HAZMAT, narcotic, or explosive material; and the detection of chemical threats, GC-MS plays a role in ensuring our safety.
Techniques That Complement GC-MS
Why Choose Covalent for Your GC-MS Needs?
Covalent has a particularly powerful GC-MS, offering mass resolving power >30,000 and an instrument detection limit below 20 femtograms. We are fully equipped with a range of sample introduction techniques including liquid, headspace, solid-phase microextraction, thermal desorption, evolved gas analysis and pyrolysis. We have a variety of ion sources including hard (electron) and soft (chemical and field) ionization modes.