bonded phase

in chromatography
https://doi.org/10.1351/goldbook.B00700
A stationary phase which is covalently bonded to the support particles or to the inside wall of the column tubing.
Source:
PAC, 1993, 65, 819. 'Nomenclature for chromatography (IUPAC Recommendations 1993)' on page 823 (https://doi.org/10.1351/pac199365040819)