SEPARATION OF PHENOLS BY PACKED-COLUMN SUPERCRITICAL FLUID CHROMATOGRAPHY

Phenols are rapidly and efficiently separated by packed column supercritical fluid chromatography (SFC). The effect of temperature, pressure, additive identity, and concentration on retention are studied. Polar modifiers do not completely suppress tailing. The addition of a very polar additive, like trifluoroacetic acid (TFA), to a modified mobile phase improves peak shapes, apparently by covering active sites on the silica packing material. Additives sometimes continue to be retained and improve peak shapes even after removal from the mobile phase.