Endcapping
A column is said to be endcapped when a small silylating agent, such as trimethylchlorosilane, is used to bond residual silanol groups on a packing surface. It is most often used with reversed-phase packings and may cut down on undesirable adsorption of basic or ionic compounds.
End capping is the process in which unreacted silanol group (-OH) is replaced with the chemical substituent so that it will avoid the secondary interaction of analyte with the stationary phase.
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