J. Davis et al., Electrochemical detection of nitrate at a copper modified electrode under the influence of ultrasound, ELECTROANAL, 12(17), 2000, pp. 1363-1367
Ultrasound has been applied to the detection of nitrate using a copper modi
fied electrode. The electrode systems employs a macroporous copper deposit
whose response to nitrate ion has been previously characterized. This repor
t details the influence ultrasound (20 kHz) exerts on the structure of the
deposit and on the response to nitrate. The deposit was substantially remov
ed by the acoustic streaming and cavitational processes common to 20kHz ult
rasound even at relatively mild power outputs and large horn electrode sepa
rations. However, bombardment with 20 kHz ultrasound does not remove the de
posit entirely with a compact copper layer remaining. This portion of the d
eposit was found to retain significant nitrate sensitivity compared with th
e bare, unmodified electrode. The retention of the compact catalytic layer
under the influence of ultrasound enabled the use of sonolinear sweep volta
mmetry which was found to provide signal enhancement significantly greater
than the response observed under silent conditions. The analytical utility
of the technique was assessed through the determination of nitrate in treat
ed sewage outfall water. The silent and sonochemical results were found to
be within 5% of the value obtained from an independent spectroscopic analys
is.