Gas chromatography-mass spectrometry (GCMS) is an analytical technique that combines gas chromatography and mass spectrometry to identify different substances within a test sample. GCMS can be used for applications like drug detection, environmental analysis, and identifying unknown samples. It involves separating components of a sample via gas chromatography and then using mass spectrometry to identify the components based on their mass-to-charge ratios. GCMS provides advantages over traditional methods like simultaneous quantification and confirmation of targets as well as detection of non-target sample components. It has wide applications in food analysis including identification of fatty acids, sterols, flavors, and residues.

1. Gas chromatography-mass spectrometry
BY
Pintu Choudhary
Master of Technology
( Food Science and Technology)
Indian Institute of Crop Processing Technology
Ministry of Food Processing Industries
Government of India
Thanjavur - 613005
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2. Gas chromatography-mass
spectrometry
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3. Gas chromatography-mass
spectrometry
• Gas chromatography–mass spectrometry (GCMS) is an
analytical method that combines the features of Gas
chromatography and mass spectrometry to identify
different substances within a test sample
• Applications of GCMS include drug detection, fire
investigation, environmental analysis, explosives
investigation, and identification of unknown samples.
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4. Gas chromatography
• Gas chromatography is a column chromatography technique, in
which the mobile phase is gas and the stationary phase is either an
immobilized liquid or a solid packed in a closed tube.
• GC is used to separate thermally stable volatile components of a
mixture
• Gas chromatography, specifically gas–liquid chromatography,
involves vaporizing a sample and injecting it onto the head of the
column
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5. Mass Spectrometry
• Separation of molecular & atomic species
according to their mass to charge ratio.
• Used in the analysis of samples from elemental
to large proteins and polymers.
• Both qualitative and quantitative analysis
possible.
• Can be used in conjunction with gc, lc .
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6. Sample preparation
1. Introduction of (purified) sample extract onto the GC
column,
2. separation of its components on an analytical column and
3. detection of target analytes by currently the most
commonly used device—mass spectrometric (MS)
detector.
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7. Sample preparation
Sample
Size reduction
Refrigeration
Inactivation of
enzyme
Heat treatmentDrying
Cleaning
Microbial
inactivation
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8. Example of sample preparation
Fatty acids in food
Transesterification
Formation of ester to improve gas chromatographic
properties
Hydrolyze the fatty acids
Isolation
Extraction of lipids(e.g. solvent extraction )
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9. Process of analysis
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10. Process of analysis
• These materials for GC analysis may be isolated by headspace analysis
(static or dynamic), distillation, preparative chromatography (e.g., solid-
phase extraction, column chromatography on silica gel), simple solvent
extraction, or some combination of these basic methods.
• The procedure used will depend on the food matrix as well as the
compounds to be analyzed
• The primary considerations are to isolate the compounds of interest from
nonvolatile food constituents (e.g., carbohydrates, proteins, vitamins) or
those that would interfere with GC (e.g., lipids).
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11. Principle of detector
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12. Parts of GC
The major parts of a GC are the gas supply system,
• injection port,
• oven,
• column,
• detector,
• electronics, and
• recorder/data handling system
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13. System of GCMS
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14. Advantages of GC–MS over traditional
approaches
It include :-
• Simultaneous quantification and confirmation of
target analytes
• Detection and identification of non-target sample
components
• Possibility to spectrometric-ally resolve co-
eluting peaks
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15. Application of GCMS
• Residual volatiles in packaging materials
• Separation of stereoisomers
• Headspace analysis of ethylene oxide in spices
• Aroma analysis of food
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16. Application of GCMS
• GC has been used for the determination of fatty acids, triglycerides,
cholesterol and other sterols, gases, solvent analysis, water, alcohols,
and simple sugars, as well as oligosaccharides, amino acids and
peptides, vitamins, pesticides, herbicides, food additives,
antioxidants, nitrosamines, polychlorinated biphenyls (PCBs),
drugs, flavor compounds, and many more
• GC is ideally suited to the analysis of thermally stable volatile
substances.
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17. Application
• Pesticides
• Polychlorinated biphenyls
(PCBs)
• Polychlorinated dibenzo-p-
dioxins and dibenzofurans
(PCDDs/PCDFs), dioxine-like
polychlorinated biphenyls, and
dioxine-like PCBs
• Polybrominated diphenyl ethers
(PBDEs)
• Polycyclic aromatic
hydrocarbons (PAHs)
• Mycotoxins
• Veterinary drug residues
• Acrylamide
• Chloropropanols
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18. References
• Kitson, F. G., Larsen, B. S., McEwen, C. N.: 1996,
Gas chromatography and mass spectrometry: a
practical guide, Academic Press, San Diego.
• Chester TL, Pinkston JD, Raynie DE (1996)
Supercritique fluid chromatography and extraction
(fundamental review). Anal Chem 68:487R–514R
• Nielsen S (2010) ,Food analysis,Sringer,USA.
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