Experimental determination and calculation of distribution coefficients between air and fiber with polydimethylsiloxane coating for some groups of organic compounds

This paper reports the results of experimental determination of distribution coefficients Kfa for five terpene hydrocarbons and five aliphatic ketones between air and polydimethylsiloxane (PDMS) coating for solid-phase microextraction. To estimate the values of Kfa for compounds of the same classes, which did not undergo experiments, it is proposed to use an empirical two-parameter equation in which various physico-chemical and structural characteristics weakly correlated with each other are used as descriptors. It is also shown that for these purposes it is possible to use distribution coefficients of compounds in any other two-phase heterogeneous system, e.g. octanol–water or hexane–acetonitrile. This approach was applied to estimate Kfa values of 92 volatile organic compounds.