relative retention time - ratio between the net retention time of a substance and that of a standard compound.

residual silanols - the silanol (-Si-OH) groups that remain on the surface of a silica after a modifier ligands is chemically bonded onto its surface. These silanol groups may not be accessible to the reacting bulky organosilane (e.g. octadecyldimethylchlorosilane) but may be accessible to small polar compounds. Often they are removed by endcapping with a small organosilane such as trimethylchlorosilane.

See silica based bonded phases.

resolution - a quantitative measure of the separation of two peaks; it accounts for narrowness of peaks and the separation of peak maxima.

See selectivity and resolution.

response - detector characteristic which defines the detectable types of compounds by a particular detector.

See response.