column chromatography
(gcide) | Chromatography \Chro`ma*tog"ra*phy\, n. [Gr. ?, ?, color +
-graphy.]
1. A treatise on colors [archaic]
[1913 Webster]
2. (Chem.) an analytical and preparative technique for
separating substances by differences in their selective
adsorption to solids, by passing a liquid over the solid,
to which the substances to be separated have usually been
adsorbed in a preliminary step. The major variations are
column chromatography, in which the substances to be
separated are adsorbed to a column with any of a wide
variety of adsorbing solids in powdered or granulated
form; paper chromatography, in which the solids are
applied as a spot at one end of a strip of absorbent paper
(such as filter paper), and the liquid is percolated
through the paper by capillary action; and thin-layer
chromatography (TLC), which is similar to paper
chromatography, but the adsorbent material is, instead of
paper, a thin layer of finely powdered material, such as
cellulose or silica, on a backing of glass or plastic,
called a TLC plate. A modern version of {column
chromatography} is high-performance liquid chromatography,
usually referred to as HPLC.
[PJC] |