The role of pore size and stationary phase composition in preventing aqueous-induced retention time loss in reversed-phase HPLC

The phenomenon of aqueous mobile phase induced retention time loss, which has also been referred to as phase-collapse behavior, is investigated using a variety of stationary phases with an aqueous mobile phase. The loss of retention of several water-soluble B vitamins is measured as a function of silica pore size, bonded-phase chemistry, and bonded stationary phase density. It is found that these variables influence the magnitude of the retention time loss behavior and that controlling/optimizing these variables can result in a stationary phase with sufficient retention of the analyte without the column exhibiting the so-called phase-collapse behavior.