Development of N-ferrocenyl(benzoyl)amino-acid esters stationary phase for high performance liquid chromatography

A new stationary phase for high-performance liquid chromatography was prepared by covalently bonding N-ferrocenyl(benzoyl)amino-acid esters (L 1 ) onto silica gel using 3-aminopropyltriethoxysilane as coupling reagent. The structure of new material was characterized by infrared spectroscopy , elemental analysis and thermogravimetric analysis . The chromatographic behavior of the phase was illustrated in reversed-phase (RP) and normal-phase (NP) modes using polycyclic aromatic hydrocarbons (PAHs), aromatics positional isomers, amines, 5-nitroimidazoles, organophosphorus pesticides and phenols as probes. Multiple mechanisms including hydrophobic, hydrogen bonding , π–π, dipole–dipole, charge-transfer and acid–base equilibrium interactions are involved. Thus, multi-interaction mechanisms and mixed-mode separation of the new phase can very likely guarantee its excellent chromatographic performance for the analysis of complex samples. The L 1 AminoSil column was successfully employed for the analysis of organophosphorus pesticides in vegetable.