Theory of fast capillary gas chromatography - Part 3: Column performance vs. gas flow rate

At the high pressure drop required for the fast analysis of complex mixture s, the equations for the column plate height, H, and plate duration, Q, as functions of the carrier gas velocity, ii, differ substantially from the eq uations for the same quantities expressed via the carrier gas flow rate, F. While ii as an independent pneumatic variable is more convenient for the t heoretical studies, F is a more convenient as a control parameter in practi cal applications. Equations for H vs. (u) over bar and for Q vs. (u) over b ar from Parts 1 and 2 are transformed here into expressions for H vs. F and Q vs. F. An efficiency-optimized flow rate (EOF) and a speed-optimized flo w rate (SOF) are found. Expressions for these two quantities are considerab ly simpler than their velocity-based counterparts. In particular, SOF does not depend on column length, film thickness, and press;re drop.