Gas chromatography coupled with mass spectrometry (GC-MS / GC-MS/MS)
Gas chromatography-mass spectrometry (GC-MS) is a cutting-edge analytical technique that allows for the precise separation, identification, and quantification of volatile and semi-volatile organic compounds in a sample. Widely used for trace analysis, GC-MS has become a reference method in the pharmaceutical, cosmetic, food, environmental, and materials industries.
What do GC-MS and GC-MS/MS refer to?
GC -MS (Gas Chromatography – Mass Spectrometry) combines two complementary analytical steps:
- chromatography (GC) separates the different components of a mixture based on their volatility and their interactions with a chromatographic column.
- Mass spectrometry (MS) allows each separated compound to be by measuring its mass/charge ratio (m/z) after ionization, and by analyzing its fragmentation spectrum .
Each compound generates a characteristic signal, compared to reference spectral libraries for reliable identification, even at trace levels.
GC-MS/MS (or tandem MS version adds a controlled ion fragmentation step, offering increased specificity and enhanced sensitivity , particularly useful for complex matrices or compounds at very low concentrations.
How the GC-MS method works
GC-MS analysis follows several successive steps:
- Injection and vaporization : the sample is injected into the heated injector and immediately vaporized.
- Chromatographic separation : compounds migrate in a capillary column according to their volatility and affinity with the stationary phase.
- MS source ionization : the separated compounds are ionized (often by electron impact – EI) to form characteristic fragments.
- Mass spectrum analysis : each ion is detected according to its mass/charge ratio (m/z), producing a specific spectrum.
- Identification and quantification : spectra are compared to databases, or processed in SIM mode for targeted and ultra-sensitive detection.
Technical specifications of the GC-MS
- Ultra-sensitive detection : ng/g to pg/g depending on the compounds
- Analysis methods : full scan (qualitative), SIM (targeted quantitative)
- Ionization : electron impact (EI), chemical ionization (CI)
- Spectral databases : NIST, Wiley, in-house
- Associated standards : European Pharmacopoeia, USP, ISO, REACH, FCM directives, etc.
- Matrix compatibility : solids, liquids, extracts, films, environmental samples
For which matrices?
GC-MS and GC-MS/MS are suitable for a wide variety of matrices, including those containing volatile or semi-volatile :
Main industrial applications
GC-MS is used in routine analyses , product development and regulatory assessments in many industrial sectors:
Léa Géréec
Technical and scientific expert
