Elution

Elution is a term used in analytical and organic chemistry to describe the process of extracting one material from another by washing with a solvent (as in washing of loaded ion-exchange resins to remove captured ions).

In a liquid chromatography experiment, for example, an analyte is generally adsorbed, or "bound to", an adsorbent in a liquid chromatography column. The adsorbent, a solid phase (stationary phase), is a powder which is coated onto a solid support. Based on an adsorbent's composition, it can have varying affinities to "hold" onto other molecules—forming a thin film on its outside surface (or on its internal surface if there are cavities within the compound). Elution then is the process of removing analytes from the adsorbent by running a solvent, called an "eluent", past the adsorbent/analyte complex. As the solvent molecules "elute", or travel down through the chromatography column, they can either pass by the adsorbent/analyte complex or they can displace the analyte by binding to the adsorbent in its place. After the solvent molecules displace the analyte, the analyte can be carried out of the column for analysis. This is why as the mobile phase passes out of the column, it typically flows into a detector or is collected for compositional analysis.

Predicting and controlling the order of elution is a key aspect of column chromatographic methods.

Read more about ElutionEluotropic Series, Eluent, Eluate, Elution Time and Elution Volume

Other articles related to "elution":

Elution Time and Elution Volume
... The elution time of a solute is the time between the start of the separation (the time at which the solute enters the column) and the time at which the solute elutes ... In the same way, the elution volume is the volume of eluent required to cause elution ... standard conditions for a known mix of solutes in a certain technique, the elution volume may be enough information to identify solutes ...
Size-exclusion Chromatography - Analysis
... The elution volume (Ve) decreases roughly linear with the logarithm of the molecular hydrodynamic volume ... Vo determination because it is heterogeneous and may give variable results) The elution volumes of the standards are divided by the elution volume of the thyroglobulin (Ve/Vo) and plotted against the log of the ...
Displacement Chromatography - Comparison With Elution Chromatography - Characteristics of Elution Mode
... In elution mode, solutes are applied to the column as narrow bands and, at low concentration, move down the column as approximately Gaussian peaks ... where the isotherm is curved, is disadvantageous in elution chromatography because the rate of travel then depends on concentration, causing the peaks to spread and distort ... Retention in elution chromatography is usually controlled by adjusting the composition of the mobile phase (in terms of solvent composition, pH, ionic strength, and so ...
Affinity Chromatography - Batch and Column Setup
... to allow setting, a wash buffer run through the column and the elution buffer subsequently applied to the column and collected ... the liquid phase, washing, re-centrifuging, adding the elution buffer, re-centrifuging and removing the eluate ... with the target molecule bound is packed onto a column and washing and elution are done on the column ...
Displacement Chromatography
... differences between displacement and elution chromatography ... In elution mode, substances typically emerge from a column in narrow, Gaussian peaks ... The speed at which any component of a mixture travels down the column in elution mode depends on many factors ...