Flow injection chemiluminescence determination of catecholamines with electrogenerated hypochlorite

A flow injection method for the determination of catecholamines based on the inhibition of the intensity of chemiluminescence from the luminol-hypochlorite system is described. The hypochlorite was electrogenerated on-line by constant current electrolysis, resulting in the elimination of the instability of hypochlorite solution prepared from commercially available sodium hypochlorite. The detection Limits are 6x10(-10) g ml(-1) for dopamine, 8x10(-10) g ml(-1) for adrenaline and 8x10(-10) g ml(-1) for isoprenaline. Linear ranges are 1x10(-9)-2x10(-8) g ml(-1) for dopamine, 2x10(-9) - 2x10(-8) g ml(-1) for adrenaline, 2x10(-9)-2x10(-8) g ml(-1) for isoprenaline. The relative standard deviations are lower than 2.8%. The proposed method has been applied to the determination of catecholamines in pharmaceutical injections with satisfactory results. (C) 1998 Elsevier Science B.V. All rights reserved.