Reduce zone broadening in  column chromatography:

The main factors which can reduce zone broadening are

i)          The column should  be packed with smaller particles and the packing should be compact,

ii)        Column diameter should be narrow,

iii)       The thickness of the liquid layer should be minimized; and

iv)       With gaseous mobile phase, the longitudinal diffusion can be lowered by reducing the temperature. This effect is not noticeable in liquid chromatography.