After purifying an NTP by anion exchange and reverse phase HPLC, the compound is precipitated and dissolved in water, an analytical scale anion exchange HPLC is run to verify each compound is >90% triphosphate. In addition, 31P NMR, Mass Spec and UV analyses are done to ensure the triphosphate has little or no inorganic phosphate. We then match the calculated molecular weight and confirm the concentration of the final solution.