Citric acid and phosphate ion are separated by HILIC on Primesep N HILIC HPLC column. Both compounds are very hydrophilic. Citric acid and phosphate ions are well separated with excellent peak shape. Method can be used for quantitation of citrate and phosphate in various formulations. Because of the lack of UV activity, separation can be monitored by LC/MS, ELSD or Corona CAD. Method can be used for other hydrophilic organic and inorganic acids.