Normal phase and hydrophilic interaction liquid chromatography (HILIC) are primarily used to separate polar and hydrophilic compounds. In reversed phase mode very polar compounds are often not sufficiently retained in low percent organic, or even in 100% aqueous mobile phase. The order of elution in normal phase is opposite that found in reversed phase for the same mixture of compounds. Although non-polar organic mobile phases and a silica stationary phase were used traditionally in normal phase LC, today most separations are performed with aqueous-organic mobile phases and a more polar-bonded stationary phase. This mode of HPLC is now commonly referred to as HILIC, hydrophilic interaction liquid chromatography.