Cytidine phosphates are nucleotides. Nucleotides contain a nucleobase, five-carbon sugar and one or three phosphate groups. All three cytidines are very polar and cannot be retained by reversed-phase chromatography without a ion-pairing reagent. Mixed-mode Primesep SB column easily allows to retain and separate mono-, di-, and tri-phospates by anion-exchange mechanism. Other nucleotides can be separated as well by this approach. Nucleotides in biofluids can be analyzed directly on this column without any significant sample preparation. Most of the proteins from biological fluids will be repelled from the surface of silica gel. Method is compatible with UV, ELSD, CAD and LC/MS.