where (k') is the capacity ratio of the solute,
(df) is the effective film thickness of the stationary
phase,
(DS) is the diffusivity of the solute in the stationary
and the other symbols have the meaning previously ascribed to them.
Now, applying the law of Summation of Variances,
(8)
where (
) is the
total variance/unit length of the column.
Thus substituting for (
), (
),
(
) and (
) from equations
(4), (5), (6) and (7), respectively,
(9)
