Theoretical Approximation for the Linear Flow of Carrier Gas through a Rectangular Gas Chromatogaphic Column

A simple relationship for the average linear velocity of carrier gas flowing through a rectangular gas chromatographic column is derived. Since the relationship agrees remarkably well with published experimental data taken from a variety of sources, it should be very useful in practical application. This is particularly true for micro-fabricated etched silicon columns that often have a rectangular cross-section. Knowledge of the average linear velocity facilitates calculation of the height equivalent to a theoretical plate (HETP), a measure of resolution for the column.