Analytical chemistry is a vast area of applied chemistry. It comprises of techniques classified under different groups such as classical analysis, chromatography, spectroscopy, thermal, analysis, electrochemical analysis, etc. It may take a lifetime to gain expert knowledge of each and every area of analytical chemistry but a basic knowledge of some areas is a definite advantage for the laboratory chemist. On receiving a sample for analysis a chemist should be able to decide the suitable analysis technique based on its physical state, hazardous nature (if known), required analysis and concentration range over which the results of analysis are required.
The article will briefly discuss the benefits of learning about Gas Chromatography which is today an established chromatographic technique for separation, identification and quantitative estimation of volatile components present in gaseous and liquid mixtures. A known sample volume is injected into a flowing carrier gas stream comprising of the inert carrier gas, fuel gas and oxidant. On reaching the column inside the column oven the different components are retained depending on interaction with the stationary phase packed inside the column. After elution from the column the separated components are detected in a sequence on reaching the detector. The vast choice of stationary phases, temperature control of the oven and choice of detector options make Gas Chromatography a highly versatile technique with applications in diverse fields.
Knowledge of basics and principles of Gas Chromatography will prove to be an asset for the practicing chemist as well as for a fresh student who has graduated from the University and aspires to pursue higher studies or research or build a career in industrial laboratories. Interviewers at time of job interviews try to assess the basic understanding and knowledge of different analytical techniques though it is not expected that a fresh entrant will have expert knowledge in any specific area.
The section below will briefly discuss the career openings where a basic knowledge of Gas Chromatography will prove to be a definite asset.
Pollution Control Laboratories
The quality of air in cities and industrial areas is of great significance to do those who work or live in vicinityof such environments.Air monitoring is carried out at several points and average data on different pollutants like SOX, NOX, suspended particulate matter, combustion gases, vehicle emissions are reported at regular time intervals. In addition to gases present in ambient air industrial areas require round the clock monitoring of toxic vapours from fumes. The basis of such measurements is chromatographic separation and detection using sensitive detectors. More advanced instrument versions based on Gas Chromatographic principles are commercially available for automated sampling, stack monitoring of plumes and process gases.
Foods and Cosmetics
Food and cosmetics contain natural or artificial flavours that make the product appealing to the consumer. Flavours and fragrances are compounds which are highly volatile and can be detected easily by Gas Chromatography combined with mass selective detector or head space analyser at very low concentrations. The quantities of such compounds can be controlled to provide the right combination so as to appeal to the consumers.
Petroleum Products and Petrochemicals
This is an area having a large number of analysis options for different products ranging from crude oil in underground or under-sea reservoirs to fuel fractions to end products of petrochemicals including different grades of plastics and polymers. Analysis based on Gas Chromatographic principles is used to monitor and control petroleum refining operations in large-scale refineries handling hundreds of tonnes of crude oil per day.The range of analysis has diverse requirements and several modified versions of Gas Chromatographic instruments are available. These include Total hydrocarbon analysers, SIMDI Sanalysers andNatural gas analysers. Besides several other automated on-line analysers are required to monitor and control environment in large refineries for the safety of workers.
Academic Research
GC Courses also has immense potential for contributions in basic research and development of new organic molecules, modification of reaction processes and understanding the basics of reaction mechanisms.