Averaging the pressure and flow rate of the carrier gas in a gas chromatographic column

A systematic derivation of corresponding equations shows that averaging the pressure and the flow rate of the mobile phase in a gas chromatographic column over the column length and over the time that an unretained component resides in the column, requires the use of three different compressibility correction factors, j(2)(1), j(3)(2), and j(4)(3). When multiplied by the adjusted retention volume, V-R-V-M, the Martin and James mobile phase compressibility correction factor j(3)(2), only, produces the value of specific retention volume, V-g(T), which is connected unambiguously with the thermodynamic phase distribution coefficient, K, of the sorbate.