Most reports in reversed-phase liquid chromatography (RPLC) with micellar mobile phases use the anionic surfactant sodium dodecyl sulphate, which effectively masks silanol groups responsible for poor efficiency and tailing peaks in basic compounds. However, it causes excessive retention, requiring the addition of an organic solvent to reduce retention times. Non-ionic surfactants like polyoxyethylene(23)lauryl ether (Brij-35) are rarely used, despite allowing separation of various analytes without organic solvents. However, Brij-35 irreversibly adsorbs on columns and leads to poor peak shapes. Therefore, finding non-ionic surfactants with properties similar to Brij-35 but with reversible adsorption and better peak shape is important. This work explores several non-ionic surfactants for RPLC, with polyoxyethylene(10)tridecyl ether showing promise. The separation of sulphonamides, β-adrenoceptor antagonists, tricyclic antidepressants, and flavonoids (with and without hydroxyl groups on the aromatic rings) was tested, and chromatographic behaviour was evaluated in terms of retention and peak shape, with results compared to Brij-35.
