Develop a quantitative relationship:

Various attempts have been made to develop a quantitative relationship between the plate height and the column variables. One of the most accepted and in general use was providing in 1950s by a Dutch chemical engineer van Deemeter. The equation given by him, known as van Demeter equation, is in the subsequent form

H = A + B/u + Cu

where, H is the plate height (cm), u is the linear velocity of the mobile phase (cm/sec) and A, B and C are the coefficients related to the phenomena of eddy diffusion or longitudinal diffusion, multiple flow paths, and mass transfer between phases, respectively. A coefficient C could be separated in two coefficients, one pertaining to the stationary phase (C_S) and the other related to mobile phase (C_M). It means the equation can be rewritten as

H = A+B/u+ (C_S+C_M) u

Presently, we have to examine the effect of variables on the four terms, A, B/u, C_Su and C_Mu.