Editing Chromatography (section)

==Terms==
*'''Analyte''' – the substance to be separated during chromatography. It is also normally what is needed from the mixture.
*'''Analytical chromatography''' – the use of chromatography to determine the existence and possibly also the concentration of analyte(s) in a [[Sample (material)|sample]].
*'''Bonded phase''' – a stationary phase that is covalently bonded to the support particles or to the inside wall of the column tubing.
*'''Chromatogram''' – the visual output of the chromatograph. In the case of an optimal separation, different peaks or patterns on the chromatogram correspond to different components of the separated mixture.{{paragraph break}}[[File:Rt 5 9.png|300px|Chromatogram with unresolved peaks]] [[File:Rt 5 12.png|300px|Chromatogram with two resolved peaks]]{{paragraph break}}Plotted on the x-axis is the retention time and plotted on the y-axis a signal (for example obtained by a [[Spectrophotometry|spectrophotometer]], [[Mass Spectrometry|mass spectrometer]] or a variety of other detectors) corresponding to the response created by the analytes exiting the system. In the case of an optimal system the signal is proportional to the concentration of the specific analyte separated.
*'''Chromatograph''' – an instrument that enables a sophisticated separation, e.g. gas chromatographic or liquid chromatographic separation.
*'''Chromatography'''  – a physical method of separation that distributes components to separate between two phases, one stationary (stationary phase), the other (the mobile phase) moving in a definite direction.
*'''Eluent''' (sometimes spelled ''eluant'') – the solvent or solvent fixure used in elution chromatography and is synonymous with ''mobile phase''.<ref name="Borman-1987">{{cite journal |last1=Borman |first1=Stu |title=Eluent, Effluent, Eluate, and Eluite |journal=Analytical Chemistry |date=1987 |volume=59 |issue=2 |page=99A |doi=10.1021/ac00129a735}}</ref>
*'''Eluate''' – the mixture of ''solute'' (see Eluite) and ''solvent'' (see Eluent) exiting the column.<ref name="Borman-1987"/>
*'''Effluent''' – the stream flowing out of a chromatographic column. In practise, it is used synonymously with ''eluate'', but the term more precisely refers to the stream independent of separation taking place.<ref name="Borman-1987"/>
*'''Eluite''' – a more precise term for ''solute'' or ''analyte''. It is a sample component leaving the chromatographic column.<ref name="Borman-1987"/>
*'''[[Eluotropic series]]''' – a list of solvents ranked according to their eluting power.
*'''Immobilized phase''' – a stationary phase that is immobilized on the support particles, or on the inner wall of the column tubing.
*'''Mobile phase''' – the phase that moves in a definite direction. It may be a liquid (LC and [[capillary electrochromatography]], CEC), a gas (GC), or a supercritical fluid (supercritical-fluid chromatography, SFC). The mobile phase consists of the sample being separated/analyzed and the solvent that moves the sample through the column. In the case of [[High-performance liquid chromatography|HPLC]] the mobile phase consists of a non-polar solvent(s) such as hexane in normal phase or a polar solvent such as methanol in reverse phase chromatography and the sample being separated. The mobile phase moves through the chromatography column (the stationary phase) where the sample interacts with the stationary phase and is separated.
*'''Preparative chromatography''' – the use of chromatography to purify sufficient quantities of a substance for further use, rather than analysis.
*'''Retention time''' – the characteristic time it takes for a particular analyte to pass through the system (from the column inlet to the detector) under set conditions. See also: [[Kovats retention index|Kovats' retention index]]
*'''Sample''' – the matter analyzed in chromatography. It may consist of a single component or it may be a mixture of components. When the sample is treated in the course of an analysis, the phase or the phases containing the analytes of interest is/are referred to as the sample whereas everything out of interest separated from the sample before or in the course of the analysis is referred to as ''waste''.
*'''Solute''' – the sample components in partition chromatography.
*'''Solvent''' – any substance capable of solubilizing another substance, and especially the liquid mobile phase in liquid chromatography.
*'''Stationary phase''' – the substance fixed in place for the chromatography procedure. Examples include the [[silica]] layer in [[#Thin-layer chromatography|thin-layer chromatography]]
*'''Detector''' – the instrument used for qualitative and quantitative detection of analytes after separation.
  
Chromatography is based on the concept of partition coefficient. Any solute partitions between two immiscible solvents. When one make one solvent immobile (by adsorption on a solid support matrix) and another mobile it results in most common applications of chromatography. If the matrix support, or stationary phase, is polar (e.g., [[cellulose]], [[Silica gel|silica]] etc.) it is forward phase chromatography. Otherwise this technique is known as reversed phase, where a non-polar stationary phase (e.g., non-polar derivative of [[Octadecane|C-18]]) is used.