Formic acid as a milder alternative to trifluoroacetic acid and phosphoric acid in two-dimensional peptide mapping

In reversed-phase chromatography of peptides, formic acid has been shown to successfully replace the stronger traditional trifluoroacetic and phosphoric acids. Detection of non-aromatic peptide at lower wavelength is not impaired and being volatile the acid is easily removed, enabling further studies of the peptides. Also in ion-exchange chromatography (the first step of a two-dimensional approach) formic acid works well with a sulphonic acid ion-exchange resin.