Feed injection in liquid chromatography: Reducing the effect of large-volume injections from purely organic diluents in reversed-phase liquid chromatography.

In liquid chromatography (LC), discrepancies in liquid properties such as elution strength and viscosity lead to a mismatch between the sample diluent and mobile phase. This mismatch can result in peak deformation, including peak splitting or even breakthrough, particularly when large sample volumes are injected. The formation of a T-junction between sample solution and mobile phase flow stream, a technique previously used in supercritical fluid chromatography, is the key enabler of feed injection in LC.

Surface immobilized Cu-1,10-phenanthroline complexes with α-aminophosphonate groups in the 5-position as heterogenous catalysts for efficient atom-transfer radical cyclizations.

Many Cu catalyzed ATRC reactions suffer from low catalyst activity and stability. We have synthesized five 1,10-phenanthroline ligands substituted in the 5-position with α-aminophosphonate groups, through which the corresponding Cu complexes can be immobilized on AlO. These catalysts show similar activity and higher selectivity than the homogenous catalysts while being recyclable.