phenyl phase - a nonpolar bonded phase prepared by the reaction of dimethylphenyl-chlorosilane with silica gel. Claimed to have affinity for aromatic compounds.

See phenyl phase.

pirkle columns - "brush-type" chiral stationary phases, based on 3.5- dinitrobenzoylphenylglycine silica, used in the separation of a wide variety of enantiomers. Named after the developer, Dr. William Pirkle, University of Illinois.

See chiral phases.

plate height - syn. height equivalent to a theoretical plate, HETP; column length corresponding to a theoretical plate, normally found by dividing the column length by the number of theoretical plates.

See band broadening.

polarity - a measure of the separation of charges in a molecule; hydrocarbons are non-polar; alcohols are polar; more polar stationary phases interact more strongly with polar samples and usually provide a better separation.