2. GAS CHROMATOGRAPH

3. Principle:
Which type of compounds can analyse?
Volatile
Thermostable

5. Carrier gas supply: Hydrogen, Helium, Nitrogen, Argon
Requirements of a carrier gas:
Inert
High purity
Easy available
Cheap
Less risk of explosion
Best column performance
Compatible with the stationary phase and the sample and detector used

6. Carrier gas flow regulator
Carrier gas cylinder
Carrier gas flow regulator
Carrier gas cylinder, Carrier gas flow regulator

7. Sample injection devices:
Manual - Direct Injection
Automated - Auto sampler
- Purge and Trap
Commercial GC- Split &
Splitless inj.& On column inj.
Liquids
Gases
Solids

8. Gases
Position -I
Position -II
Position -I

9. .>0.1%,0.01% SPLIT RATIO:1/49,25/49UL

11. On-Column Injector

12. Columns: Column selection Column length Column diameter
Column efficiency
Column head pressure
Column cost
Column diameter

13. GC Columns Packed columns Capillary columns/Open tubular
Typically a glass or stainless steel coil.
1-5 total length and inner diameter:2 & 4mm
Packing particles diameter: 100 to 250 micrometers
porous-layer open tubular (PLOT) column
support-coated open tubular(SCOT) column
wall coated open tubular column (WCOT)

16. Packed
Capillary

17. List of common stationary phases and their polarities
Column Stationary Phase
Polarity
Diatomaceous Earth (SiO2, Al2O3, Fe2O3, CaO, MgO, Na2O, and K2O)
relatively non-polar
Clay
Celite
Squalane (C30H62) (purified with charcoal and alumina)
non-polar
Hexadecane
Apolane-87 (C87H176)
Apiexon Greases (purified with charcoal and alumina)
Dialkyl Phthalates
moderately polar
Tetrachlorophthalates
Polyethylene Glycol (Carbowax 20M)
Polysiloxanes
non-polar-polar (depending on the R group attached)

18. List of functional groups attached to the stationary phase and their polarities
Stationary Phase Functional Group
Polarity
Polyester Phases
Highly Polar
-OH
Polar
-CN
-CO
Hydrocarbons
Non-polar
Dialkyl Siloxanes

19. Analyte Functional Groups (Polar to Non-polar)
Water
Acids
Alcohols
Amines
Amides
Aldehydes
Ketones
Esters
Ethers
Aromatics
Hydrocarbons

20. Column Oven The oven can be operated in two manners:
A gas chromatography oven, open to show a capillary column
The oven can be operated in two manners: 
isothermal programming
temperature programming

21. The effect of column temperature on the shape of the peaks

22. Detection Systems
Characteristics of the Ideal Detector: The ideal detector for gas chromatography has the following characteristics:
1. Adequate sensitivity
2. Good stability and reproducibility.
3. A linear response to solutes that extends over several orders of magnitude.
4. A temperature range from room temperature to at least 400oC.

23. Characteristics of the Ideal Detector
5. A short response time that is independent of flow rate.
6. High reliability and ease of use.
7. Similarity in response toward all solutes or a highly selective response toward one or more classes of solutes.
8. Nondestructive of sample.

24. Type of Detector Applicable Samples Detection Systems
Flame Ionization (FID) 
Hydrocarbons 
Thermal Conductivity (TCD) 
Universal 
Electron-Capture (ECD) 
Halogenated hydrocarbons 
Argon ionisation detector
Organic compounds
Nitrogen Phosphorous detector
Molecules containing N2/P

25. These properties allow FID high sensitivity and low noise.
Flame Ionization Detectors
Advantageous :
the detector is unaffected by flow rate, noncombustible gases and water. 
These properties allow FID high sensitivity and low noise. 
relatively easy to use. 
Disadvantages:
this technique does require flammable gas and also destroys the sample. 

26. The Electron Capture Detector
used for detecting environmental samples as the device selectively detects organic compounds with moieties such as halogens, peroxides, quinones and nitro groups .
best suited in applications where traces quantities of chemicals such as pesticides are to be detected
high selectivity and sensitivity towards certain organic species with electronegative functional groups. 

27. Thermal conductivity detector
advantages :
ease and simplicity of use
application to inorganic and organic compounds, and the ability of the analyte to be collected after separation and detection. 
drawback :
TCD is the low sensitivity of the instrument in relation to other detection methods, in addition to flow rate and concentration dependency

29. Nitrogen Phosphorus Detector