It is a basic presentation about gas chromatography,its components,working principle,procedure,applications and advantages over other.

2. INTRODUCTION
Name: SADOON ALI ZAHID
Registration #:529-FBAS/BSBT/F13
Subject: Pharmaceutical Chemistry
Topic: Gas Chromatography (G.C)

3. OUTLINES
Chromatography
Types of Chromatography
History
Gas Chromatography (G.C)
Gas Chromatography main components
Working principle of Gas Chromatography
Procedure of Gas Chromatography
Factors affecting Gas Chromatography
Advantages of Gas Chromatography
Application of Gas Chromatography
 Conclusion

4. Chromatography
Greek words “CHROMA” and
“Graphein”.
Process of separation and
analyzation of complex mixture.
Chromatography is a great
physical method for observing
mixtures and solvents.

5. How it works?
It works on the basis of rate at
which the types of components
flow. As the mixture of various
components enter the
chromatograph we will observe
that the different components of
a mixture move/flow at different
rate. This different rate of flowing is
responsible for the separation of
their components.

7. Types of Chromatography

8. History
 FRITZ PRIOR

9. Gas Chromatography
 Gas chromatography is separation
method.
Gas chromatography is
a chromatographic technique that
can be used to separate volatile
organic compounds.
 Gas Chromatography consists of
two phases.
 Mobile Phase
 Stationary phase

10. GAS CHROMATOGRAPH
MAIN COMPONENETS:
Carrier Gas
Injection Port
Column
Oven
Detector
Sample

13. CARRIER GAS
This is the mobile phase and
should be inert gas(He, Ar, H2,
N2 etc.)
INJECTION PORT
The injection port consist of
rubber septum through which a
syringe needle is inserted to
inject the sample.

14. COLUMN
Column is the most important
component where separation
takes place.
OVEN
Oven is also an important
component in which column is
fitted.

15. DETECTOR
Detector is to indicate the
presence and measure the
amount of component eluted
out from the column.
SAMPLE
The mixture of components
which is to be analyzed.

16. Properties of carrier Gas
 The carrier gas must be chemically inert.
 Commonly used gases include nitrogen,
helium, argon, and carbon dioxide.
 The choice of carrier gas is often dependant
upon the type of detector which is used.
 The carrier gas system also contains a
molecular sieve to remove water and other
impurities.
- P inlet 10-50 psig

17. Column Types
 There are two general types of
column, packed and capillary (also known
as open tubular).
 Packed columns contain a finely divided, inert,
solid support material ( diatomaceous earth)
coated with liquid stationary phase. Most
packed columns are 1.5 - 10m in length and
have an internal diameter of 2 - 4mm.
 Capillary columns have an internal diameter of
a few tenths of a millimeter. They can be one of
two types; wall-coated open tubular (WCOT)
or support-coated open tubular (SCOT).

18. Ideal GC-Detectors
 Sensitive (10-8-10-15 g solute/s)
 Operate at high T (0-400 °C)
 Stable and reproducible
 Linear response
 Wide dynamic range
 Fast response
 Simple (reliable)
 Nondestructive
 Uniform response to all analytes

19. WORKING PRINCIPLE OF GC
It works on the principle that the
organic compounds are separated
due to differences in their
partitioning behavior between
Mobile phase and Stationary
phase.
The mobile phase is comprised of
inert gas.
The stationary phase consists of
packed column.

20. PROCEDURE OF GC
 Sample is injected in column.
 Oven heats the system to vaporize
the sample and speed its passage
through the column.
 The different components of the
sample will be separated by the
column because each of the
components “sticks” to the liquid
coating that on the column
packing differently.

21. PROCEDURE OF GC
 When a substance leaves the
column, it is sensed by a detector.
 The detector generates the voltage
that is proportional to the amount of
the substance.
 Chromatogram

23. FACTORS AFFECTING GC
Temperature: The higher the
temperature, the more of the
compound is in the gas phase.
Carrier gas flow: If the carrier
gas flow is high, the molecules do
not have a chance to interact with
the stationary phase.
Column length: The longer the
column is the better the separation
usually is.

24. Amount of material injected:
The injection of too much
sample causes poor
separation.
Effective Factor: High
temperatures and high flow
rates decrease the retention
time, but also deteriorate the
quality of the separation.

25. Applications
 Miscellaneous-analysis of foods like carbohydrates,
proteins, lipids, vitamins, steroids, drug and pesticides
residues, trace elements
 Pollutants like formaldehyde, carbon monoxide,
benzene, DDT etc.
 Dairy product analysis- rancidity
 Separation and identification of volatile materials,
plastics, natural and synthetic polymers, paints, and
microbiological samples
 Inorganic compound analysis

26. Advantages
 The technique has strong separation power and even complex
mixture can be resolved into constituents
 The sensitivity of the method is quite high
 It gives good precision and accuracy
 The analysis is completed in a short time
 The cost of instrument is relatively low and its life is generally
long
 The technique is relatively suitable for routine analysis

27. Conclusion
Gas Chromatography is one
of the most important tools in
chemistry because of its
simplicity, sensitivity and
effectiveness in separating
components of mixtures. It is
widely used for quantitative
and qualitative analysis of
mixtures and for the
purification of compounds.