Chromatography

Chromatography describes a chemical process in which a mixture of substances is separated into a stationary and a mobile phase, which is possible due to the different distributions of its individual components. Depending on the procedure, the stationary phase consists of a solid substance or a fluid and the mobile phase consists of a gas or a liquid. Various methods are applied in chromatography, which provide advantages or disadvantages, depending on the application area. Paper chromatography, thin layer chromatography, column chromatography and gas-chromatography are the most important of these methods. (A short explanation of the various methods will follow later). There are practical applications for chromatography in many of areas, e.g. in production, in which the chromatography is used for cleaning and isolating of substances. In the chemical analysis, chromatography is used to separate mixtures of substances into preferably uniform components. Chromatography has an important role in many areas of chemistry, including amongst others organic chemistry, biochemistry, inorganic chemistry, environmental chemistry and food chemistry. You will soon be able to find equipment and accessories for the chromatography on this page. If you can't find the chromatography equipment you are looking for, please contact us and we will help you find the best solution which suits your needs: UK customers +44(0) 23 809 870 30 / US customers (561) 320-9162. Our technical staff will advise you regarding our products. Our engineers and technicians will be happy to help you with the chromatography equipment, and of course, with the other products in the field of regulation and control, measuring instruments or scales and balances of PCE Instruments Ltd.

Paper chromatography: Paper chromatography is part of the “fluid chromatography”. Here, the stationary phase consists of a paper strip, which stands vertical in a glass container, while the mobile phase consists of a liquid. The movement of the mobile phase is caused by the capillary forces. Applications for paper chromatography are in the analysis of mixtures of substances. 

Thin layer chromatography: Thin layer chromatography is part of the “fluid chromatography” and operates the same way as paper chromatography. The difference between the two procedures lies in the stationary phase. In thin layer chromatography, this phase is built up of pulverised material such as aluminium oxide, silica gel or cellulose, which is applied to thin glass plates. The advantages of thin layer chromatography are the fast operating time and the high detection sensitivity.

Column chromatography: Column chromatography is part of the “fluid chromatography”. In column chromatography, the stationary phase mostly consists of powdery silica gel or aluminium oxide, which is added to a glass tube and then filled up with a solvent (mobile phase). In this process, the sample is brought together with the mobile phase in the glass tube. In doing so, the ingredients of the assay are separated and leave the tube one after another. A common application for column chromatography lies in the in purification of preparations.

Gas chromatography: In gas chromatography, the two following procedures are used: 
1. Gas-fluid-chromatography
2. Gas-solid-chromatography

The most frequently used procedure is the gas-fluid-chromatography procedure. During this procedure, the substrate (e.g. silicone oil) is filled into a spiralled tube with a diameter of 0, 1 – 5 mm and a length of up to 5 meters. The gas mixture which is to be analysed streams through the spiral together with the carrying gas (azote, helium, argon). At the end of the spiral, a heat conductance-detector measures the temperature variations. Out of these temperature variations, the material components can be deduced.