(Rs). Ability of a column to separate chromatographic peaks. It is usually expressed in terms of the separation of two peaks. One attempts to achieve the best resolution possible. Resolution can be calculated in two ways: Rs = 2(tR.2 - tR.1)/(Wb.1 + Wb.2) or Rs = 1/4(a-1/a) (k'/1+k')N1/2 A value of 1 is considered to be the minimum for a measurable separation to occur and to allow good quantitation . Values of 1.7 or larger are generally desirable for rugged methods