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Column chromatography in chemistry is a chromatography method used to isolate a single chemical compound from a mixture. Chromatography is able to separate substances based on differential absorption of compounds to the adsorbent; compounds move through the column at different rates, allowing them to be separated into fractions.
Chromatography columns of different types are used in both gas and liquid chromatography: Liquid chromatography: Traditional chromatography columns were made of glass. Modern columns are mostly made of borosilicate glass, acrylic glass or stainless steel. To prevent the stationary phase from leaking out of the column interior a polymer ...
Today, most GC columns are fused silica capillaries with an inner diameter of 100–320 micrometres (0.0039–0.0126 in) and a length of 5–60 metres (16–197 ft). The GC column is located inside an oven where the temperature of the gas can be controlled and the effluent coming off the column is monitored by a suitable detector. [1]
Chromatography, pronounced / ˌ k r oʊ m ə ˈ t ɒ ɡ r ə f i /, is derived from Greek χρῶμα chrōma, which means "color", and γράφειν gráphein, which means "to write".". The combination of these two terms was directly inherited from the invention of the technique first used to separate biological pigme
Oldershaw columns have the same theory of operation as industrial plate columns. They are highly efficient for fractionating but they have significant holdup (the amount of liquid in the column during use) and their complexity makes them one of the more expensive types of glass column.
Air-free techniques refer to a range of manipulations in the chemistry laboratory for the handling of compounds that are air-sensitive. These techniques prevent the compounds from reacting with components of air , usually water and oxygen ; less commonly carbon dioxide and nitrogen .
The amount of heat entering the column from the reboiler and with the feed must equal the amount heat removed by the overhead condenser and with the products. The heat entering a distillation column is a crucial operating parameter, addition of excess or insufficient heat to the column can lead to foaming, weeping, entrainment, or flooding.
The reflux system in a typical industrial distillation column. Reflux is a technique involving the condensation of vapors and the return of this condensate to the system from which it originated. It is used in industrial [1] and laboratory [2] distillations. It is also used in chemistry to supply energy to reactions over a long period of time.