SONOCHEMICAL STRIPPING VOLTAMMETRY

A new form of stripping analysis is described which exploits the extre me conditions produced during sonication. Sonochemical stripping volta mmetry differs from other forms of stripping analysis in that the prec oncentration of the analyte is sonochemical rather than electrochemica l. Zero-valent metal particles are melted onto the electrode surface a fter being accelerated by microjets formed due to acoustic cavitation. The electrode is then transferred to an electrolyte solution for volt ammetric analysis via linear sweep or square wave voltammetry, This al lows the deposition to occur in nonelectrolytic or complex matrices. S onochemical deposition of copper onto gold electrodes is demonstrated both electrochemically and microscopically by scanning electron micros copy, Using square wave voltammetry, a linear relationship is demonstr ated between extent of copper deposition from a Cu/DMSO slurry and son ication time up to 15 min. There is also a linear dependence of respon se on the amount of copper in the slurry. Selectivity based on the mel ting point of the metal in the slurry is shown, both electrochemically and with scanning electron microscopy, through sonication of slurries containing copper and tungsten powders. Finally, deposition of copper from lubricating oils mixed with organic diluents illustrates the uti lity of the technique for samples of practical importance. It also dem onstrates that information concerning the viscosity behavior of non-Ne wtonian fluids under conditions of extreme temperature and shear rate is obtainable, despite dilution with an organic solvent.