Stability-indicating hydrophilic interaction liquid chromatography method for highly polar and basic compounds

A hydrophilic interaction liquid chromatography (HILIC) method was developed for the analysis of very polar and basic 4-(aminomethyl)pyridine (4-AMP) and its related compounds. Separation parameters such as stationary phase, buffer pH, buffer ionic strength, organic modifier, and column temperature were evaluated. The retention mechanisms were explored through the evaluation of the common chromatographic parameters in the method development. The data indicated the existence of surface adsorption phenomena for 4-AMP and its positional isomers (2-AMP, 3-AMP). For two degradants, different retention mechanisms might be involved when compared to 4-AMP. The selectivity of two critical pairs 3-/4-AMP isomer and Degradant-1/-2 diastereomer changed through isoelution temperature with reversal of elution order. The validation results indicated that the HILIC method is a sensitive, reproducible, and robust method suitable for the analysis of 4-AMP and its related compounds.