Simultaneous determination of nitrite and nitrate anions using capillary electrophoresis-sample stacking technique: Application to food samples

A capillary electrophoresis-sample stacking method was developed for the simultaneous analysis of nitrite and nitrate ions in this work. An acidic buffer was selected and electroosmotic flow was reduced with this way. Consequently, the anions were detected in a very short time. The sensitivity of the method was increased by applying a sample-stacking technique. When detection limits of both ions are compared between small volume injection and sample stacking modes, it was observed that the stacking mode resulted in a thirtyfold improvement in detection sensitivity for both anions. The method was successfully applied to canned fish samples, namely tuna, mackerel and sardine.