Column chromatography in chemistry is the preparative application of chromatography. It is used to obtain pure chemical compounds from a mixture of compounds on a scale from micrograms up to kilograms using large industrial columns. Chemistry (derived from alchemy) is the science of matter at or near the atomic scale. ... Chromatography is a family of analytical chemistry techniques for the separation of mixtures. ... A chemical compound is a chemical substance formed from two or more elements, with a fixed ratio determining the composition. ...

Column chromatography on a large scale in the 1950s, the chemist uses a ladder to refill eluent, he operates not one but 11 columns, barely visible are erlemeyer receptibles on the floor

The classical preparative chromatography column is a glass tube with a diameter from 5 to 50 mm and a height of 50 cm to 1 m with a tap at the bottom. A slurry is prepared of the eluent with the stationary phase powder and then carefully poured into the column. Care must be taken to avoid air bubbles. A solution of the organic material is pipetted on top of the stationary phase. This layer is usually topped with a small layer of sand or with cotton or glass wool to protect the shape of the organic layer from the velocity of newly added eluent. Eluent is slowly passed through the column to advance the organic material. Often a spherical eluent reservoir or an eluent-filled and stoppered separating funnel is put on top of the column. ImageMetadata File history File links Colortest. ... A slurry is a sloppy mixture, which comes in different varieties: Metal Slurry can be used in pipe fitting and other welding tasks, as well as slurry based bombs like the BLU-82. ... In chromatography an eluent is the liquid or gas entering a chromatographic bed (e. ... Chromatography is a family of analytical chemistry techniques for the separation of mixtures. ... Separating funnel A separating funnel or separation funnel or separatory funnel is a piece of equipment used in science to separate two immiscible liquids or solutions of different densities. ...

The individual components are retained by the stationary phase differently and separate from each other while they are running at different speeds through the column with the eluent. At the end of the column they elute one at a time. During the entire chromatography process the eluent is collected in a series of fractions. The composition of the eluent flow can be monitored and each fraction is analyzed for dissolved compounds, e.g. by analytical chromatography, UV absorption, or fluorescence. Colored compounds (or fluorescent compounds with the aid of an UV lamp) can be seen trough the glass wall as moving bands. Fractional distillation is the separation of a mixture of compounds by their boiling point, by heating to high enough temperatures. ... Ultraviolet (UV) light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than soft X-rays. ... Fluorescence induced by exposure to ultraviolet light in vials containing various sized Cadmium selenide (CdSe) quantum dots. ... Fluorescence induced by exposure to ultraviolet light in vials containing various sized Cadmium selenide (CdSe) quantum dots. ... Ultraviolet (UV) light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than soft X-rays. ...

Stationary phase (adsorbent)

The stationary phase or adsorbent in column chromatography is a solid. The most common stationary phase for column chromatography is silica gel, followed by alumina. Cellulose powder has often been used in the past. Also possible are ion exchange chromatography, reversed-phase chromatography (RP), or affinity chromatography. The stationary phases are usually finely ground powders or gels and/or are microporous for an increased surface. Some examples of silica gel sachets Silica gel is a granular, porous form of silica made synthetically from sodium silicate. ... Flash point Non-flammable. ... Cellulose (C6H10O5)n is a long-chain polymeric polysaccharide carbohydrate, of beta-glucose. ... The ion-exchange chromatography process allows the separation of ions and polar molecules based on the charge properties of the molecules. ... Affinity chromatography is a biochemical separation method that combines size fractionation capability of gel permeation chromatography with the ability to design a stationary phase that reversibly binds to a known subset of molecules. ...

Mobile phase (eluent)

The mobile phase or eluent is either a pure solvent or a mixture of different solvents. It is chosen so that the R_f value of the compound of interest is roughly around 0.75 in order to minimize the time and the amount of eluent to run the chromatography. The eluent has also been chosen so that the different compounds can be separated effectively. The eluent is optimized in small scale pretests, often using thin layer chromatography (TLC) with the same stationary phase. In chromatography an eluent is the liquid or gas entering a chromatographic bed (e. ... A solvent is a liquid that dissolves a solid, liquid, or gaseous solute, resulting in a solution. ... Chromatography is a family of analytical chemistry techniques for the separation of mixtures. ...

Flow rate

A faster flow rate of the eluent minimizes the time required to run a column and thereby minimizes diffusion, resulting in a better separation, see Van Deemter's equation. A simple laboratory column runs by gravity flow. The flow rate of such a column can be increased by extending the fresh eluent filled column above the top of the stationary phase or decreased by the tap controls. Better flow rates can be achieved by using a pump or by using compressed gas (e.g. air, nitrogen, or argon) to push the solvent through the column (flash column chromatography). The Van Deemter equation gives the variance per unit length of a packed column in terms of the physical properties of the solute and phase system and the linear mobile phase velocity. ... Gravity is a force of attraction that acts between bodies that have mass. ... General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless Atomic mass 14. ... General Name, Symbol, Number argon, Ar, 18 Chemical series noble gases Group, Period, Block 18, 3, p Appearance colorless Atomic mass 39. ...

See also

• Chromatography, an overview article covering all chromatographic techniques.
• High performance liquid chromatography (HPLC) for column chromatography using high pressure.
• Fast protein liquid chromatography (FPLC) for separation of proteins using column chromatography.

Chromatography is a family of analytical chemistry techniques for the separation of mixtures. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... Fast Protein Liquid Chromatography, usually referred to as FPLC, is a form of column chromatography used to separate or purify proteins from complex mixtures. ...

External links

• Column chromatography howto
• Column chromatography Technologies
• Flash Column Chromatography Guide (pdf)