Thin-Layer and Gas Chromatography

The purpose of this paper is to analyze the various differences that can be noted between thin layer chromatography and gas chromatography as seen in the various laboratory tests carried out in class.

1) Thin layer chromatography is where in the stationary phase consists of a powdered adsorbent and it is constant/ fixed in an aluminum, plastic or glass plats. Then the mixture that is meant to be analyzed is loaded at the bottom of the glass or plastic plate. The plate that is used is placed in something known as a reservoir of the solvent; it is only the bottom of the plate in place that is submerged (Pascal, 2000). The solvent in the phase that is known as the mobile phase have a tendency of moving up the plate resulting to the distribution of the components used in the mixture between the moving solvent and what is known as adsorbent which is found in the plate. If one separates the components used in the mixture for the purpose ensuring that components are in separate spots as they will be appearing from the bottom of the plate as well as to the top of the plate. On the other hand Gas chromatography in the stationary phase it is characterized by a highly boiling liquid which is a waxy substance or viscous oil. The highly boiling liquid which is packed in a narrow, long metal or glass column. The mixture meant to be analyzed is then loaded by use of syringe at the beginning of the column. At the mobile phase there is an inert gas that is continuously flowing through the narrow column. The components contained in the mixture then distribute themselves between the mobile gas and the highly stationary boiling liquid which are moving in the column used. The mixture of the gas flows through the detector in the end of the column and it separation is successful; the components will show some different peaks or blips on the recorder.

From the above analyses the following  differences can be noted between thin layer chromatography and gas chromatography; In the thin layer chromatography, the mobile phase has a liquid wile in the stationary phase  is in form of solid. It is mainly useful in comparison of mobility of some dissolvable liquid and solid as well as separating them (Laurence, 1989).

On the other hand Gas chromatography, in the mobile phase there is gas while in the stationary phase there liquid which is on solid. It is serve the purpose of separating gases by use of their affinities as seen in the stationary phase.

The most important points to be noted is what happens in the mobile and stationary phase as they form the basis of analyzing the two types of chromatography.

2) The laboratory tests that caught my attention is determination of solvent systems for column and thin layer chromatography. They caught my attention because thin layer chromatography tents to have elution patterns that extrapolate to the column elution patterns. This is the case because thin layer chromatography tends to be faster compared to column chromatography in its procedures(Still, 1918). For example while determining the system that is solvent for the flash chromatography steps, the system that is ideal tend to move from the intended component contained in the mixture .Mixture can be analyzed through usage of thin layer chromatography in order to determine the solvent which is ideal for what is known as flash chromatography steps/ procedures. This caught my attention as many of beginners do not have this knowledge. This is the case due to the toxicity, cost involved and finally lack of knowledge on the subject of chromatography.