Abstract
In this study, pulsed ultrasound hydrodynamic modulation (PUHM) voltammetry was developed for determination of trace components in small sample volumes. With this method, the current components corresponding to ultrasonic pulse-on and pulse-off can be recorded separately, and the current difference between the two states was found to be proportional to the concentration of the electroactive species. Because the current difference is essentially free of high background interference arising from electrode surface processes, solvent decomposition and double-layer charging which are observed in normal voltammetric measurements, relatively lower detection limits were achieved. The analytical usefulness of this approach was exploited for determination of ferrocyanide ion in small sample volume as low as 200μl with the detection limit of sub-micromolar level. It also demonstrates the considerable promise of this technique for the detection of electroactive species in a region of the potential window normally obscured by solvent from the result of Ru(bpy)_3^<2+> determination.
