band - mobile phase zone which contains a sample component; band is usually in the column; peak is the band signal on the chromatogram.

band broadening - effect of spreading of the chromatographic band while it moves though the column. Band broadening occurs due to the eddy diffusion, longitudinal diffusion and slow mass transfer. Band broadening value expressed as column efficiency.

See band broadening.

baseline - constant signal produced by the background level of the instrument; usually represented by a flat line on the recorder.

See also noise and drift.

biocompatible - term to indicate that the column or instrument component will not irreversibly or strongly adsorb or deactivate biomolecules such as proteins.

bonded phase - silica is traditionally the common "normal" chromatography packing material. When another material is chemically bonded to the surface of the silica, a new adsorbent with unique surface chemistry and separation properties can result. Historically this bonded molecular layer is called "bonded phase". When an alkyl group is chemically joined to a silica surface, a hydrophobic paraffinic packing is obtained. Similarly, amine, sulfonic acid, or nitrile groups could be bonded to silica.

See bonded phases.