Determination of Carbonate and Bicarbonate in Colored Oilfield Underground Water by Ion Chromatography

A new ion chromatography has been set up to determine the carbonate and biocarbonate in colored oilfield water samples. By optimizing the chromatographic conditions, the total carbonate-carbon can be analyzed in less than 8 min, and then the content of the carbonate and bicarbonate in the sample is conveniently calculated through acid-base equilibrium. The linear relationship between the total contents of carbonate-carbon and responses is satisfied in the range of 0.24～12 mmol/L. The limit of detection of this method is 0.24 mmol/L total carbonate-carbon, relative standard deviation is less than 5.0 % and recovery is 95 %～105 %.