Figure 3.

Determination of the bioavailable fraction of the polycyclic hydrocarbon compounds using solid-phase microextraction (SPME) in a defined mixture of analytical standards. A, Effects of SPME measurements on the percent distribution of the polycyclic hydrocarbon compounds. Black bars represent the total amount of the polycyclic hydrocarbon in the neat defined mixture. Gray bars indicate the bioavailable amount of the polycyclic hydrocarbon determined via SPME. B, Overall bioavailable fractions of different polycyclic hydrocarbon molecular subclasses (n = 3, mean ± SD).