gc & gc vs hplc
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Gc & gc vs hplcTRANSCRIPT
DERIVATIZATION OF GAS CHROMATOGRAPHY & COMPARISION OF GAS CHROMATOGRAPHY & HPLC
GUDIED BY:
Mr. UTTAM PRASAD PANIGRAHY
PRESENTED BY:
M.Srilatha
Pharmaceutics
COMPARISION OF GC&HPLC
GAS CHROMATOGRAPHY In this technique a stream of
carrier gas that act as mobile phase is passed over a fixed stationary phase placed inside the column.
Principle:- GLC=Partition chromatography. Gsc=Adsorption
chromatography
HIGH PERFORMANE LIQUID
CHRROMATOGRAPHY In this technique a
liquid mobile phase is pumped at a high pressure through a suitably modified column that acts as a stationary phase.
Principle:- separation in HPLC is adsorption.
Depending upon the nature of stationary phase used.
1) Gs-liquid chromatography:
Mobile phase-Gas Stationary phase-Thin
layer of non-volatile liquid or a polymer coated innert solid
Ex;Porous polymer, sand glass beads.
2)Gas-solid chromatography:-
Mobile phase-Gas Stationary phase-solid
adsorbent Ex; silicon rubber,poly
ethylene glycol
Techniques of HPLC are classified based on
I. Modes of chromatographyII. Normal phase mode:- Mobile phase-Non polar-Ex; hydrocarbon solvent alcohols. Stationary phase-silica gel3)Reverse phase mode:- Mobile phase-polar-Ex; methanol with water aqueous
buffer Stationary phase-non polar-Ex; alcohol chlorinated, solvents.
2)HPLC-principle of separation:-
1. Adsorption chromatography:- Adsorption2. Ion- exchange chromatography:-Reversible
exchange of ions.3. Gel permeation chromatography:-Molecular filtration4. Affinity chromatography:-Affinity of analytic towards
stationary phase
3)Elution technique:- Isocratic separation Gradient separation4)Scale of operation:- Analytical HPLC Pre-operative HPLC5)Type of analyse:- Qualitative analysis Quantitative analysis
The concept of gas chromatography between 1941&’1943
Instruments used are simple, less expensive.
Equipment cost is 8 lacks above
pore size- Gaseous and volatile
compounds can be easily separated and analysed
The concept of the HPLC between 1967&’1969
HPLC columns are expensive&eqiupment cost is high.
Equipment cost is 15-20lacks above
Pore size-3-10µm Gaseous and volatile
compounds cannot be easily separated and analysed
Thermo stable compounds
can be analysed
Preparation of mobile phase is easy. Ex;H2gas
Mobile phase cannot be recovered
It requires temperature programming.Ex;Linearmode
Samples need to be heated at elevated temperatures. If it is not in the gaseous state
Ex;Thermostable
Thermo labile compounds can be easily separated and analysed
Preparation of sample and solvent is laborious& time consuming process.
Mobile phase can be recovered
Temperature. programming is not essential
Sample treatment is not required when aqueous or non aqueous samples are to be analysed
Instrumentation
includes:-a) Gas supply unitb) Sampling unitc) Columns unitsd) Injection devicee) Detectorsf) Recorders Precolumn is not
required.
Instrumentation includes:-
a) Solvent delivery systemb) Injectionc) Columnsd) Analytical columnse) Solvent degassing
gradient controllerf) Detector g) Recorders A pre column is
essential that increases the efficiency of chromatographic separation.
Ex; Guard columns
Glass columns are most commonly used because they can withstand higher temperature
Sampleunit,column&detector needs an oven to maintain higher temperature
Column length few centimetres to several hundred meters
Column used-packed columns
Capillary &open tubular
Analytical& preparative
Stainless steel columns are commonly used because they can withstand high pressure.
Only column unit needs an oven
Column length 25cm-100cm
Columns used-conventional columns
Micro bore columns
A. Bulk property:-
Refractive indexdectorsConductivity detectors
B. Solute property:-UV-visible detector
Fluorescence detectorsElectro chemical
detectors
A. Concentration dependent:- Thermal conductivity
detector Electron capture detector Argon ionization detector
B. Mass flow dependent Nitrogen phosphorous
detector Flame photometric
detectors
Detectors used are 2 types-