Human Blood and Plasma Partition Coefficients for C4-C8 n-alkanes, Isoalkanes, and 1-alkenes

Human blood:air and plasma:air partition coefficients for C-4-C-8 n-alkanes, isoalkanes, and 1-alkenes were determined using multiple headspace extraction coupled with solid phase microextraction and gas chromatography. Mean blood:air partition coefficients expressed in the form of dimensionless blood-to-air concentration ratio (g/mL(b)/g/mL(a)) were 0.183, 0.416, 1.08, 2.71, and 5.77 for C-4-C-8 n-alkanes; 0.079, 0.184, 0.473, 1.3, and 3.18 for C-4-C-8 isoalkanes; and 0.304, 0.589, 1.32, 3.5, and 7.01 for C-4-C-8 1-alkenes, respectively (n = 8). The reported partition coefficient values increased exponentially with boiling points, molecular weights, and the carbon atoms in the particle. The solubility of 1-alkenes in blood was higher than in plasma, whereas the blood:air and plasma:air partition coefficients of n-alkanes and isoalkanes did not differ significantly. Consequently, additional interactions of 1-alkenes with whole blood seem to occur. The presented findings are expected to be particularly useful for assessing the uptake, distribution, and elimination of hydrocarbons in human organism.