GAS CHROMATOGRAPHIC DETERMINATION OF VAPOUR PRESSURES OF PHEROMONE-LIKE COMPOUNDS .3. ALDEHYDES

摘要

Equilibrium vapour pressures of six saturated and seventy-four mono-unsaturated C-10-C-16 even-carbon aldehydes were determined using a method based on gas chromatographic (GC) retention data. GC measurements were carried out on a 3-m HP-1 capillary column at five to seven temperatures in the range of 35-140 degrees C by utilising saturated n-C-12, n-C-13, n-C-17 and n-C-18 hydrocarbons as vapour pressure reference standards. A close correlation, viz. lnP [Pa] = 14.008 - 1.105n(c) (r = 0.9996) has been found between the vapour pressures P and the number of carbon atoms (n(c)), indicating a vapour pressure decrease by a factor of 3.02 for each CH2 group added in the alkanal chain. For structurally similar subseries of alkenals (omega-3, omega-5 and omega-7 unsaturation), the vapour pressures were also shown to have a simple dependence on n(c). Within each alkenal subseries, isomers having Z-configuration had mostly greater vapour pressures than their E-counterparts.