The present invention provides silica-based reversed-phase HPLC methods
that lead to higher retention of the analytes in the column and longer
column lifetimes than usually observed under medium to high pH aqueous
mobile phase conditions. The inventive methods comprise eluting the HPLC
column using an aqueous mobile phase comprising at least one fluorinated
additive. Preferred additives are polyfluorinated alcohols such as
2,2,2-trifluoroethanol and 1,1,1,3,3,3-hexafluoroisopropanol. The methods
of the present invention may be used for analyzing, separating,
purifying, and/or isolating small organic molecules, natural products, as
well as biomolecules such as polypeptides, oligonucleotides and
polynucleotides (e.g., DNA fragments).