Newly developed perfluorinated polyethers, HOCH O CF O CF 2 2 p 2 . x Ž . CF O CH OH Z-Dols , were separated using packed capillary column supercrit-2 q 2 Ž . ical fluid chromatography SFC . A fluorocarbon-bonded stationary phase, Fluofix Ž .
120N 5 m and 120 A , was used as a packing material and the performance of this stationary phase was investigated under different experimental conditions. The effects of column length, pressure, and temperature on separation were studied. Approximately 180 oligomers of perfluorinated polyethers with an average molecular weight range from 2000 to 4000 were well resolved using an 85 cm = 200 m i.d. column at 110ЊC under pressure programming conditions. The chromatographic behavior of the fluorocarbon-bonded stationary phase was compared with octade-Ž . cyl silica ODS particles under SFC conditions. The results show Fluofix 120N has more selective retention than ODS for perfluorinated polyethers. The effects of Freon F-113, methanol, and water as sample solvent on stationary phase stability were also examined. It was found that the column efficiency with the Fluofix 120N stationary phase did not deteriorate significantly using Freon and methanol as sample solvents but decreased by 30% using water at 110ЊC for 48 h.