PPT KA II KROM.GAS SUSI

GAS CHROM ATOGRAPHY (GC)

By: Susila Kristianingrum
susila.k@uny.ac.id
Basic Competencies:
Students can describe the separation of GC,
interpretation chromatograms, and apply this
separation method for the analysis of a sample

USAGE GC
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The oil (pet roleum)
The field of essent ial oils
The field of medicine
Chemist ry / research

Pest icide
Environment / pollut ion

BENEFITS OF USE GC
 Fast
Operat ion is simple
Sensit ive (order of ppm, ppt ), mL, mg
The separat ion (resolut ion) high
Qualitat ive and quant itat ive analysis
High repeatabilit y

ANALYSIS OF CHROM ATOGRAPHY
 GAS-LIQUID: PARTITION
 GAS-SOLID: ADSORPTION
 Qualitat ive analysis: based on chromat ogram
peak t hat appears

 Quant itat ive analysis: a high peak areas or
peak chromat ogram

Gas-Solid Chromatography (GSC)
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M obile phase: gas
Stat ionary phase: non-volat ile solids ,
stable
For example: spheron (Grafit e-coal),
linden (molecular sieves) porapak,
polypak, chromosorb

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Basic work: t he separat ion of molecules
based on size

Gas-Liquid Chromatography (GLC)
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Terms of t he solid support :

1. Stable at high t emperat ures
2.Inert , not react ing w it h samples &
stat ionary phase
3.The large surface area (grain)
4. Ideal sit uat ion (same size)

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Examples of solid support :
Diat oport , cilit e, chromosorb (G, P, W)

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Working basis:
separat ion based on part it ion bet ween mobile
phase and stat ionary phase

Gas-Liquid Chromatography (GLC)
• M obile phase: gas
• Stat ionary phases: liquid, t he condit ion:

1. Non volat ile
2. Inert & stable
3. Very viscous
4. Spread & bound t o a solid support
5. Soluble in organic solvent (et her)

Gas-Liquid Chromatography (GLC)
 This t ype of stat ionary phase: polar, semi polar,
non polar

 Examples of polar stat ionary phases:
carbowax 20M , PEGA, DEGS,
cast orwax, amine 220, versamid 900,
PDEAS

 Examples of semipolar stat ionary phases:
dionilftalat , SE-52 (OV-17)

 Examples of non-polar stat ionary phases:
apiezon, Squalane, SE-30

Classificat ion of compounds
POLAR
water
Glycol, glycerol
alcohol
Oksim
Hydroxy acids
ester
etc.

Classificat ion of compounds
SEM I POLAR
et her
ketone
aldehyde
tert iary amine
etc.

• NON POLAR

CHCl3
CH2Cl2
aromat ic hydrocarbons
olefin hydrocarbons
CH3CHCl2
etc.

BASIC SEPARATION
Rule: like dissolves like

Compounds

nat ure

Polar

Stationary
Phase
Polar

Soluble

Non polar

Non polar

Soluble

Polar

Non polar

insoluble

Non polar

Polar

insoluble

CHROM ATOGRAM
 GAUSS CURVE
1. Eddy diffusion and molecular
2. The balance of slow
3. Price K is not fixed

 IDEAL chromat ogram
1. Quickly balance
2. No diffusion
3. uniform column

INSTRUM ENTS GC

COM PONENTS INSTRUM ENTS GC

 Carrier gas tank (+ regulat or)
 Place t he sample inject ion
 column
 det ect or
 Amplifier + Recorder

Carrier gas tank (+ regulator)

Place t he sample inject ion

column

Detector
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FID
TCD
FPD
ECD

FID Detector
• Basic work: sample + burner gas (H2 + air/O2)

burned
Ionization occurs: positive ion to
negative electrode, negative ion to positive
electrode
• On electrodes occurs: Change Voltage (V)
Change of voltage forwarded to the recorder and
produce chromatogram.
• Advantages: highly sensitive (1000xTCD).
• Disadvantages: damaged samples, detecting
water insoluble, CS2, O2, N2, CO2, and the
noble gases.

TCD Detector / Chatarometer
• Conditions: t he t emperat ure of t he det ect or
must be higher t han column t emperat ure

• Basic principles: Component s w hich have been
separat ed from t he column carried by t he
carrier gas on t he filament . Change of filament
t emperat ure causes filament resistance .

Resistance filament s changed by Wheat st one
bridge become current . Change current arus
forwarded t o t he recorder and t hen convert ed
become chromat ogram.

TCD Detector / Chatarometer
• Advantages:
1. Does not dest roy t he sample
2. All kinds of compounds can be det ect ed.

• Disadvantage:
less sensit ive.