Gas Chromatography Essay

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Chromatography means "color writing" literally from the Greek words chroma and graphe. It is a separating technique for a mixture of chemicals, which can be in gas or liquid form, by letting them creep slowly past another substance. There are two important things in chromatography that is it must has one state of matter such as gas or liquid, that is known as mobile phase, moving over the surface of another state of matter which can be liquid or solid that stays where it is that is known as stationary phase. As the mobile phase moves, it separates out into its components on the stationary phase and identify one by one afterwards. (1)
The development of Gas Chromatography (GC) to be an analytical technique to separate the components of a mixture
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The retention of analyte molecules happened due to stronger interactions with the stationary phase than the mobile phase. In another words, there is higher affinity of sample towards stationary phase than mobile phase that caused retention. The interaction types can be divided into Dispersive, Dipole and Hydrogen…show more content…
Packed columns with typical dimension 1.5 m x 4 mm are usually packed with a solid support coated with immobilized liquid stationary phase material namely Gas-Liquid Chromatography. Whereas, capillary columns with typical dimension 30 m x 0.32 mm x 0.1 mm film thickness are the long hollow silica tubes with the inside wall of the column coated with immobilized liquid stationary phase material and may also contain solid stationary phase particles namely Gas-Solid Chromatography. Open tubular columns are known as capillary columns can be divided into two. The first one is wall-coated open tubular (WCOT) column and the second type is support-coated open tubular (SCOT) column. WCOT columns are capillary tubes that have a thin layer of the stationary phase coated along the column walls. The column walls of SCOT are first coated with a thin layer of adsorbant solid, such as diatomaceous earth and then treated with the liquid stationary phase. SCOT columns are able to hold a greater volume of stationary phase than a WCOT column due to its greater sample

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