Anions are most commonly analyzed by ion chromatography, ion selective electrodes or flow injection analysis.These methods are easy to use, but lack of sensitivity or specificity for some analysis.Anions have also been detected by electrospray ionization (ESI) in the negative mode in combination with liquid chromatography (LC).Unfortunately negative ESI lacks the sensitivity seen in positive ESI due to corona discharge, signal instability from solvents and arcing.