PH04 Advances in Analysis and Measurements
Exhibit Hall
8:00 AM - Thursday
(PH013) Sonoelectrochemical determination of some heavy metals in water and biofluids.
Nei, L1, Kruusma, J1, 1 Environmental Protection Institute, Tartu, Estonia
ABSTRACT- Heavy metals play a vital role in the functioning of a healthy body. However, when the concentrations of these metals become either too high or too low, the effects can be very serious. Our aim is to develop sonoelectroanalytical techniques for monitoring of a wide variety of trace elements in water, food products and blood. We have concentrated on sonoelectroanalytical detection of three heavy metals: cadmium, lead and zinc. The quantitative detection of cadmium, lead and zinc in water and biofluids is shown to be possible by anodic stripping voltammetry under conditions of insonation. An immersion horn probe is introduced into a thermostatted conventional three-electrode cell opposite a working electrode. The enhanced mass transport associated with power ultrasound yields efficient pre-concentration of the metal ion before it is detected using anodic differential-pulse stripping voltammetry. Insonation further offers the crucial benefits of first surface activation and cleaning, helping to prevent electrode fouling by the organic components in liquid and second fully equilibrating free and bound metal ions in the complex matrix. Acoustic streaming and cavitation promote the mass transport to the surface of electrode, facilitating measurements in solutions of low metal concentrations, where silent measurements fail to yield an analytical signal. The system is calibrated using standard micro additions of cadmium, lead or zinc to give the total amount of the detected metal. The values of cadmium, lead or zinc concentrations obtained using sonoelectroanalytical methodology were compared with the results obtained by independent atomic absorption spectroscopy (AAS) measurements and a good agreement was found.
Key words: water, heavy metals, biofluids