Determination of the Octanol-Air Partition Coefficients (KOA) of Fluorotelomer Alcohols


Octanol-air partition coefficients (KOA) for five fluorotelomer alcohols (4:2 FTOH, 6:2 FTOH, 8:2 FTOH, 10:2 FTOH, and for the first time 12:2 FTOH) were determined over a temperature range from (5 to 40) °C using a modified generator column method. Octanol-saturated air at a fixed temperature was blown over a column filled with glass spheres which were coated with an FTOH solution. FTOHs partitioning to the gas phase were collected on a trap filled with XAD-2 and eluted with acetone afterward. The concentrations of FTOH were measured by GC-MS using positive chemical ionization. The KOA values were calculated as the ratio of the FTOH concentrations in the octanol to the FTOH concentrations in the air. Values of log KOA at 25 °C ranged from 4.5 (4:2 FTOH) to 6.2 (12:2 FTOH). The calculated internal energies of phase change (ΔUOA) ranged from 42.8 kJ · mol-1 (12:2 FTOH) to 61.1 kJ · mol-1 (4:2 FTOH). The combined uncertainty of the method applied ranged from 8.3 % (4:2 FTOH) to 10.5 % (10:2 FTOH). The expanded uncertainty (P ) 95 %) ranged from 18.7 % (4:2 FTOH) to 38.7 % (10:2 FTOH), respectively.
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