Gas Chromatography Mass Spectrometry (GC-MS) Information

GC/MS targets small and volatile molecules

GC/MS is the analysis method of choice for smaller and volatile molecules such as benzenes, alcohols and aromatics, and simple molecules such as steroids, fatty acids, and hormones. It can also be applied towards the study of liquid, gaseous and solid samples.

There are many advantages to using GC/MS for compound analysis, including its ability to separate complex mixtures, to quantify analytes, and to determine trace levels of organic contamination.


GC/MS begins with the gas chromatograph, where the sample is volatized. This effectively vaporizes the sample (the gas phase) and separates its various components using a capillary column packed with a stationary (solid) phase. The compounds are propelled by an inert carrier gas such as argon, helium or nitrogen. As the components become separated, they elute from the column at different times, which is generally referred to as their retention times.

Once the components leave the GC column, they are ionized by the mass spectrometer using electron or chemical ionization sources. Ionized molecules are then accelerated through the instrument’s mass analyzer, which quite often is a quadrupole or ion trap. It is here that ions are separated based on their different mass-to-charge (m/z) ratios.

The final steps of the process involve ion detection and analysis, with compound peaks appearing as a function of their m/z ratios. Peak heights, meanwhile, are proportional to the quantity of the corresponding compound. A complex sample will produce several different peaks, and the final readout will be a mass spectrum. Using computer libraries of mass spectra for different compounds, researchers can identify and quantitate unknown compounds and analytes.

GC is the separation technique of choice for smaller and volatile molecules such as benzenes, alcohols and aromatics, and simple molecules such as steroids, fatty acids and hormones. It is widely used for chemical analysis, and especially for drug and environmental contamination testing. When combined with MS, GC/MS can be used in both full scan MS or select ion monitoring (SIM) mode to cover either a wide range of m/z ratios or to gather data for specific masses of interest, respectively.

In this section, you will:

  • Learn which mass spectrometry instruments and technologies are best suited to sample analysis by GC/MS.
  • Understand how GC/MS helps analyze volatile and small molecules.
  • Learn about workflows specifically designed for samples undergoing analysis by GC/MS.

GC/MS features

Application note

Sensitive and specific GC-MS/MS is critical during routine testing for drugs of abuse in urine. Find out how such high level drug testing is performed.  

Webinar

Understand how GC/MS, when coupled to HRAM technology, helps elucidate targeted and untargeted compounds during a single pesticide analysis workflow.

Forensic ebook

Remove doubt with these mass spectrometry workflows when working on forensic cases.


GC/MS information subtopics

GC/MS Sample Preparation

Learn how GC/MS enables the analysis of volatile and thermally stable samples including pesticides, environmental pollutants, solvents, aromatics, and drug metabolites.


Mass Spectrometry Resource Library

Further your knowledge of mass spectrometry applications and technologies with our comprehensive collection of applications and technical notes, peer-reviewed journal publications, webinars, posters and more.

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