Chromatography

2 definitions found

From The Collaborative International Dictionary of English v.0.48 [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]

From WordNet (r) 2.0 [wn]:

  chromatography
       n : a process used for separating mixtures by virtue of
           differences in absorbency