Understanding the response factors of a GC detector

Gas Liquid Chromatography (GLC) or simply Gas chromatography (GC)is a versatile technique that helps identify and quantify constituent compounds of complex organic mixtures. Primarily such compounds should be volatile in nature and should not decompose at high temperatures inside the injector and the column oven.  The technique offers a wide choice of detectors. For any […]

10 Similarities between High Performance Liquid Chromatography (HPLC) and Gas Chromatography (GC)

The dissimilarities between HPLC and GC were discussed in the earlier article- How are Gas chromatography (GC) and High Performance liquid chromatography (HPLC) different?. The present article discusses 10 key features which are common to both the techniques. On going through these features you will recollect your basic understanding of chromatography and appreciate the commonality […]

How are Gas Chromatography (GC) and High Performance Liquid Chromatography(HPLC) different?

Gas Chromatography is an ideal technique for separation and identification of gases or volatile liquids having low molecular weights. The basis of separation is selective distribution of components present in gaseous phase on the solid adsorbent inside a column or on a thin liquid layer adsorbed on an inert solid support or on the inside wall […]

Gas Chromatography in Petroleum Refining Industry

Gas chromatography has found large-scale applications in monitoring of petroleum refining and finished product testing. This is evidenced by evolution of several dedicated versions of techniques based on Gas Chromatography. Large-scale refining operations require fast decisions on process parameter changes as delays of even a minute can result in colossal losses so these are overcome […]

Which type of gas regulator is suitable for Gas Chromatography?

Before answering the question you should understand the role a regulator plays. The regulator supplies gas at constant pressure to the Gas Chromatograph. Cylinder regulators are fixed direct to the gas cylinder valve and serve to reduce the cylinder pressure to a value suitable enough for the Gas Chromatograph. Such valves are of two types, […]

Why Capillary Columns are preferred over Packed Columns in Gas Chromatography

A column is a major component of a Gas Chromatograph in which separation of sample components takes place. Gas chromatographic columns are classified into two major categories, namely, packed columns and capillary columns. The types of columns have been discussed in the free course on gas chromatography. A question that often comes up is which […]

Hydrogen, Helium or Nitrogen – Which is most suitable as a Carrier Gas?

A carrier gas serves as a medium for transport of eluting molecules through the Gas Chromatograph. Before deciding on the carrier gas you should consider the following Inertness towards the sample components Should not attack system components Should not give its own response signal Should be available in highly pure state Should be cost-effective and […]

What are the Differences between GC and HPLC?

Gas chromatography and High Performance Liquid Chromatography are both separation techniques which have gained immense popularity in both academic and industrial laboratories. High Performance Liquid Chromatography has found favour in applications covering pharmaceuticals, foods, life sciences and polymers whereas Gas Chromatography has significant applications in petroleum and petrochemical industry, flavours and fragrances and, environmental air monitoring,. A general […]

How to handle Gas Chromatographic Gases Safely?

Gas chromatography analysis requires high purity compressed gases. The three Gas Chromatographic gases commonly used are: Inert Carrier Gas – Helium or Nitrogen Fuel Gas – Hydrogen (FID operation) Combustion Support Gas – Air (FID operation) The Gas Chromatographic gases are supplied in compressed gas cylinders which are colour coded and require careful handling to prevent accidents. […]

How Derivatisation is useful in GC analysis?

Derivatisation has been used in the analysis by Gas Chromatography in some situations to modify properties of analyte molecules to give desirable response for: Improvement of volatility so that thermally unstable compounds do not decompose at higher temperatures Improvement of detector response Improvement of peak shape Resolution of closely spaced peaks by derivatising one component […]