Abstract: A fast determination method for salt content in crude oil by ion chromatography was developed. The samples were extracted by high frequency oscillation extraction using mixture of water, ethanol, and xylene. The column-switching technique was then used on line to eliminate the interference of ethanol in extraction solution in chromatography analysis. Then the chloride was detected by ion chromatography. The results show a great linear relationship in the concentration range from 0.1 to 100 mgNaCl/L, the correlation coefficient is greater than 0.999. The detection limit for ion chromatography is 0.01 mgNaCl/L based on S/N of 3. The difference between this method and the coulometry method is not significant. The column-switching ion chromatography can meet the analysis requirement of salt content in crude oil but much fast and simple.

Key words: ion chromatography, column-switching, salt content, crude oil