Chemical affinity

Affinity (from the Latin affinitas = relationship - it was formerly believed that substances that react with each other, have some kind of relationship with each other would have ) is the driving force of a chemical reaction, namely the tendency of ions, atoms or groups of atoms, a ( covalent ) to enter into binding ( reaction affinity). Competing two metal ions to oxygen, it is called oxygen affinity. However, is based solely on a bond electrostatic attraction of the binding partners, one speaks of binding affinity.

The so-called affinity chromatography makes use of this type of interaction between the potential binding partners for the purposes of purification: a chemically stable pseudo- substrate (not implementable, most small molecule ) is bound to a carrier and serves to the binding partner (e.g. a protein) that has a high affinity for this has to withhold and thus get rid of impurities.