Nitrous oxide as carrier gas in capillary gas-liquid chromatography

On use of nitrous oxide as carrier gas the retention factors of the chromatographed compounds decrease linearly with increasing average column pressure, Other retention characteristics (relative retention, retention index) change linearly, This effect was demonstrated by using a capillary column coated with nonpolar polydimethylsiloxane phase SE-30. As shown for capillary GLC the linear correlation is valid for the same column: k(i)(G(1),P-1) = A k(i)(G(2),P-2) + B, where ki(G1,P1) and ki(G2,P2) are the retention factors of compound i at average column pressures P-1 and P-2 when using carrier gases G(1) and G(2), respectively; A and B are coefficients.