Further results of QCM using for heavy metals determination in water

Abstract

The electric current can deposit heavy metal ions on the surface of quartz crystal microbalance (QCM) electrode as it is connected to the minus of electric source. The kind of metal deposition from water solution depends on electrode voltage correctly to electrochemical series of metals. The gradual increase of voltage results in progressive deposition of next metal correctly to electrochemical series. The metal deposition results in decrease of resonant frequency of QCM sensor. The inverted process is also possible. The initial deposition of metals and gradual dissolution of them by reverse direction of current results in increase of sensor resonant frequency. The QCM sensitivity is very high. The frequency measurement resolution below 1 Hz, for 10 MHz sensor, results in mass resolution below 3 ng. It makes possible ions concentration measurement with resolution below 50 /spl mu/g/L. In tele and radio research institute the laboratory measurement stand for determination of heavy metal ions concentration was elaborated. The experimental measurements of ions concentration were carried out for Cu and Ni ions in cooperation with institute of meteorology and water management. The results of these investigations showed possibility to distinguish the kind of metals and determination in range 50-10000 /spl mu/g/L. The results obtained are very promising for analytical measurements.