Abstract: In order to determine the content of NaCl quickly and accurately in the separation of alkali and salt，ion chro- matography was introduced.An analysis method for the determination of chloridion by ion chromatography was established.Shedox anionic chromatography analysis column，sodium carbonate solution，and conductivity detector were selected for the determination.In the experiment，the influences of sodium carbonate and sodium bicarbonate in alkali liquid on the determination of chloridion were detected and standard sample conditions were obtained.Furthermore，the peak time was shortened by improving the leacheate（such as concentration，flow rate，and organic reagent）.Under the optimized conditions，the peak time could be shortened from 11.682 min to 8.367 min.This method had better accuracy，and the relative standard deviation（RSD） and standard sample recovery rate were 0.89%（n= 6）  and 98.73%, respectively.

Key words: ion chromatography, chloridion, sodium carbonate, sodium bicarbonate