A hydrogen bond is a form of the electrostatic force of attraction which takes place between the hydrogen atom and a more electronegative atom such as nitrogen, fluorine, and oxygen.
Hydrogen bond falls in the category of weak forces.
In size-exclusion chromatography, the type of interaction that takes place between the proteins and dextran is hydrogen bonding.
The hydrogen bonding is possible because dextran, being a polysaccharide of glucose has several hydroxyl groups and thus, they get involved in the hydrogen bonding.