APPLICATION OF THE SHATS EQUATION FOR PREDICTING RETENTION IN REVERSED-PHASE AND NORMAL-PHASE LIQUID-CHROMATOGRAPHY

To predict retention parameters in liquid chromatography in both the column (HPLC) and thin layer (TLC) variants with binary mobile phases (MP) wide use is made of the Soczewinski equation [1] lg k'= R(M) = -a lg m2+b, (1) where k' = (1/R(f)) - 1 is the capacity coefficient; m2 is the concentration of the more active component of the binary MP; a and b are equation coefficients. Equation (1) is usually well obeyed over a wide range of MP compositions in reversed-[2] and normal-phase liquid phase chromatography [3], which is the reason for its common use in practice.