The Arrangement of a Combined Voltammetric-Potentiometric Sensor with the Solid Silver Amalgam Bridge
J. Heyrovsky Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Prague
An electroanalytical measurement scheme of a combined voltammetric-potentiometric sensor was designed, comprising a working electrode inserted into the internal solution of a proper depolarizer (e.g., 10 ppm Cu(II) in 0.2 M acetate buffer, containing 2 % of tartaric acid), which is separated from the analyzed solution by Ag or other solid amalgam links (SAL). Preparation of the Ag SAL was described. The sensor was successfully tested using solutions containing 1 - 14 ppm Hg(II). Linear dependences of voltammetric current or Ag SAL potential on logarithm of concentration were obtained. In contrast to ion-selective electrodes, the sensors can be also used for the determination of metal ions coordinated in complexes.
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