Determination of total sulfur in canola oil

Abstract

AbstractA rapid and sensitive chromatographic method for the determination of total sulfur in canola oil is described. All forms of sulfur in the oil are quantitatively converted to sulfate in an oxygen bomb. The sulfate is separated from other ions and measured using an ion chromatograph equipped with a conductivity detector. Standards containing different forms of sulfur were prepared and analyzed with this method. Recovery achieved on 11 compounds covering the concentration range from 9.3 to 143.5 mg/kg S ranged from 95.7% to 102.2%. The coefficient of variability of total sulfur in canola oils ranged from 1.0% to 2.9%. Values obtained on high sulfur content mustard oils when plotted vs the values determined by barium precipitation method showed a correlation coefficient of 0.997 and provided a slope of 1.0. This new method employing comparatively simple equipment requires less than 40 minutes for a complete analysis and is reliable for the determination of as little as 0.5 mg/kg S in canola oil.