Gas chromatography-mass spectrometry (GC-MS) is an analytical technique that combines gas chromatography and mass spectrometry to identify different substances within a test sample. It works by separating chemical mixtures using gas chromatography and then analyzing the components at a molecular level using mass spectrometry. The GC-MS instrument is composed of a gas chromatograph to separate molecules and a mass spectrometer to capture, ionize, accelerate, deflect, and detect the ionized molecules to identify compounds by their mass. It has various applications including environmental monitoring, pharmaceutical analysis, drug metabolism studies, food analysis, and medical diagnosis.

1. A
Special Report
On
Gas Chromatography- Mass spectrometry : Principle,
Instrumentation and Application

2. CONTENTS
 General Introduction
 Principle
 Instrumentation
 GC-MS Setup
 Types of Mass Spectrometer detector
 Application

3. General Introduction
 Gas Chromatography – Mass Spectrometry (GC-MS) is
an analytical method that combines the features of
gas- liquid chromatography and mass spectrometry to
identify different substances with in a test sample.
 Gas chromatography is a technique used to separate
drugs that might be present in a sample. The detector
for the GC is the Mass spectrometry detector.
 Mass spectrometer(MS) is an instrument that serves
for establishment of the molecular weight and
structure of both inorganic and organic compounds,
and the identification and determination of analytes
in complex mixtures.

4. Principle
 GC-MS instrument separates chemical mixtures (the
GC component) and identifies the components at a
molecular level (the MS component).
 GC works on the principle that a mixture will separate
into individual substances when heated. The heated
gases are carried through a column with an inert gas.
 As the separated substances emerge from the column
opening , they flow into MS.
 Mass spectrometry identifies compounds by the mass
of the analyte molecule.

7. Instrumentation
 The GC-MS is composed of two major building blocks:
 Gas chromatograph
 Mass spectrometer
 The molecules are retained by the capillary column and
elute from the column at different times.
 The Mass spectrometer capture, ionize, accelerate, deflect
and detect the ionized molecules separately by breaking
each molecule into ionize fragments and detecting these
fragments using their mass to charge ratio.

9. GC-MS Setup

10. Types of Mass spectrometer Detectors
1. Quadrupole Mass Spectrometer- most common
2. Ion Trap Mass Spectrometer
3. Magnetic Mass Spectrometer

11. Quadrupole Mass Ion Filter

12. Ion trap Filter

13. Advantages of GC-MS
 Accurate identification of a particular molecule is
possible.
 Differentiate between multiple molecules in the
same amount of time.
 Identification carried out at a molecular level.
 Easy to Operate.

14. Application
 Environmental monitoring and cleanup
 Assay of pharmaceuticals and purity and
characterization of raw materials
 Studies of Drug metabolite
 Characterization of Odour and flavor component
of food
 Law enforcement
 Sports Anti- doping analysis
 Medical Diagnosis
 Security of Airports
 Criminal Forensics

15. Thank
You