Skip to main content

Gas Chromatography

Gas Chromatography (GC) - 


The chromatographic technique where the mobile phase is a gas.
GC is currently one of the most popular methods for separating and analyzing compounds.  This is due to its high resolution, low limits of detection, speed, accuracy and reproducibility.
GC can be applied to the separation of any compound that is either naturally volatile (i.e., readily goes into the gas phase) or can be converted to a volatile derivative.  This makes GC useful in the separation of a number of small organic and inorganic compounds.
Equipment:
A simple GC system consists of:
1. Gas source (with pressure and flow regulators)
2. Injector or sample application system
3. Chromatographic column (with oven for temperature control)
4. Detector & computer or recorder



Carrier gas: He (common), N2, H2
Pinlet 10-50 psig
Flow = 25-150 mL/min packed column
Flow = 1-25 mL/min open tubular column
Column: 2-50 m coiled stainless steel/glass/Teflon
Oven: 0-400 °C ~ average boiling point of sample
Accurate to <1 °C
Detectors: FID, TCD, ECD, (MS)
Mobile Phase: GC separates solutes based on their different interactions with the mobile and stationary phases. 
Carrier gas – Main purpose of the gas in GC is to move the solutes along the column, mobile phase is often referred to as carrier gas.
Common carrier gas: include He, Ar, H2, N2. 

CLICK HERE👉GC Practical Experiment

Advantages Gas-solid chromatography (GSC):
- long column lifetimes
- ability to retain and separate some compounds not easily resolved by other GC methods, viz. 
geometrical isomers, permanent gases etc.

Disadvantage: 
- very strong retention of low volatility or polar solutes
- catalytic changes that can occur on GSC supports
- GSC supports have a range of chemical and physical environments, viz. different strength retention sites ‚ non-symmetrical peaks‚ variable retention times

Labels:

Comments

Post a Comment

Popular posts from this blog

(B.L.E.V.E) Boiling Liquid Expansion Vapour Explosion & UVCE Explosion.

👉B.L.E.V.E. (Boiling Liquid Expanding Vapour Explosion).  A BLEVE (Boiling Liquid Expanding Vapour Explosion) is experienced when  containers of liquefied gases, are exposed to fires. It results from the failure of a vessel containing a liquid or a liquefied gas at a temperature significantly above its boiling point at normal atmospheric pressure. In case of container failure, a large fraction of  the superheated liquid flashes to vapour, resulting in the sudden generation of a large amount of flammable gas. " CLICK:- Everything about BLEVE " Considering the large amount of liquefied gases which are in use both in the industry and society, the risk of BLEVEs is high, as is also evident from large number of instances of BLEVEs, both within and outside industrial premises. Amongst the most  dangerous of such explosions are the rupture of liquefied gas containers such as large Horton spheres, bullets (both fixed and mobile), smaller cylinders, etc. If such ...
Post a Comment
Read more

HYDRANT SYSTEM EXPLAINED

  Introduction :   All tires in initial stage are small and can be fought easily then and there if trained fire men and well maintained Hand Appliances are available, close to the place of occurrence of tire. Hand Appliances are therefore, of immense importance as they will not let the small lire take to large proportions. F ire multiply to large sizes perhaps because of scheduled areas like warehouses, automatic plants requiring minimal man power, people are available but are not trained for the purpose. Extinguishers and Buckets are not properly maintained they may be empty or not operative at all etc. it is then when comes the role of well laid Fire Hydrant System. Fire hydrant system is capable of extinguishing tires of large sizes in small time if it is handled by trained personnel. As a matter of fact a well designed and well laid F ire Hydrant Service is the back bone of the entire available fire fighting means as it lights fires of serious proportions in al...
Post a Comment
Read more

Fire Entry Suit & Fire Proximity Suit.

Fire Proximity Suit: A fire Proximity suit(also, silvers or silver bunker suit) is a suit designed to protect a fire fighter from high temperatures, especially near fires of extreme temperature such as aircraft fires.   Fire proximity suits first appeared during the 1930's, and were originally made of asbestos fabric(hence also known as the asbestos suit). Today, they are manufactured from vaccum deposited Aliminized material that reflect the high radiant loads produced by the fire. There are three basic types of these Aluminisied suits: Approach suited for work in the general area of high temperatures such as steel mills and smelting facilities. Proximity suited for aircraft rescue and fire fighting(AR-FF) and, in more heavily insulated versions, for work requiring entry into the heated area.  •Entry suited for entry into extreme heat and situations requiring protection from total flame engulfment.  •Complete proximity protection for AR-FF requires....
Post a Comment
Read more