The performance concept: A contribution to the modern theory of capillary GC

An original theoretical approach, the “performance concept” is introduced. This concept enables the linear carrier gas velocity and column length to be optimized in order to obtain the shortest possible analysis time for a required separation. The optimized gas velocity and column length are expressed as functions of the B and C coefficients of the HETP equation, the extra-column equipment constant, σ²_EC, and the necessary plate number, N_ne, determined by the analytical problem. A new equation is given for predicting analysis time as a function of the same parameters. The validity of the concept is illustrated with an example of such an optimization. The fundamental relationships have been proved experimentally and excellent agreement found between predicted and measured values.