Interpretation of the real plate number concept: A fundamental analysis

The real plate number concept is interpreted in terms of the fundamental properties of a chromatograph. It is shown that the linear relationship between the total peak width at half height, (b_0.5)T, t, and k is only an approximation of the more general linear relationship between (b_0.5)²T, t and (1 + k)². In the case where the relationship between (b_0.5)T, t and k approaches linearity, it is concluded, firstly, that b₀ = a, i. e., b₀ is a column property and independent of extra-column phenomena and, secondly, that n_real=n_theor. When the relationship becomes non-linear, b₀ is determined partly by extra-column phenomena, but not in terms of a useful relationship. It is concluded that it is unnecessary to introduce the parameters a, b₀ and n_real, since they all have counterparts in the established theory of chromatography. These counterparts prove to be equally useful in the practical analysis of chromatographic systems.