The ordinary reversed phase high performance liquid chromatography (HPLC)

reversed phase ion pair HPLC and reversed phase ion suppression HPLC. The for separation and analysis licorice acid

has been compared by means of reversed phase column. The retention value of these three method systemly and the influence of composition of mobile phase

ion suppression agent concentration and velocity of flow etc. to the retention time

capacity index and theoretic number of tower plate has been studied

at the same time.