Reading Material 
      ●Skoog, Holler and Crouch:  Ch. 22 (An Introduction to 
         Electroanalytical Chemisty)
      ●See also Skoog et al. Chapters 23-25.
      ●Cazes:  Chapters 16-19
      ●For those using electroanalytical chemistry in their work, 
         the following reference is recommended:
                                                                       nd
            A. J. Bard and L. R. Faulkner, “Electrochemical Methods”, 2  
            Ed., Wiley, 2001.   
    Advantages of Electroanalytical Methods
   Matched against a wide range of spectroscopic 
   and chromatographic techniques, the techniques 
   of electroanalytical chemistry find an important 
   role for several reasons:
    – Electroanalytical methods are often specific for a 
     particular oxidation state of an element
    – Electrochemical instrumentation is relatively 
     inexpensive and can be miniaturized
    – Electroanalytical methods provide information about 
     activities (rather than concentration)
                History of Electroanalytical Methods
       Michael Faraday: the law 
         of electrolysis
           – “…the amount of a substance deposited 
              from an electrolyte by the action of a 
              current is proportional to the chemical 
              equivalent weight of the substance.”
       Walter Nernst:  the Nernst 
                                                         Michael Faraday     Walter Nernst
         equation (Nobel Prize                             (1791-1867)        (1864-1941)
         1920)
       Jaroslav Heyrovsky:  the 
         invention of polarography:  
         (Nobel Prize 1959) 
                                                                 Jaroslav Heyrovsky
                                                                    (1890-1967)
        Main Branches of Electroanalytical Chemistry
                      Interfacial                              Bulk methods
                       methods
                                    Dynamic                    Conductometry
      Static methods                methods                      (G = 1/R)
          (I = 0)                    (I > 0)
                                                                   Based on Figure 22-9 in Skoog, Holler and 
      Potentiometry                                                Crouch, 6th ed.
           (E)           Controlled            Constant 
                          potential             current 
    Voltammetry      Amperometric               Electro-           Coulometric 
      (I = f(E))       titrations              gravimetry            titrations
                        (I = f(E))                (m)                (Q = It)
     Key to measured quantity:  I = current, E = potential, R = resistance, G = 
       conductance, Q = quantity of charge, t = time, vol = volume of a standard solution, 
       m = mass of an electrodispensed species
   Main Branches of Electroanalytical Chemistry
   Potentiometry: measure the potential of electrochemical 
   cells without drawing substantial current
   – Examples: pH measurements, ion-selective electrodes, 
    titrations (e.g. KF endpoint determination)
   Coulometry:  measures the electricity required to drive an 
   electrolytic oxidation/reduction to completion
   – Examples:  titrations (KF titrant generation), 
    “chloridometers” (AgCl)
   Voltammetry:  measures current as a function of applied 
   potential under conditions that keep a working electrode 
   polarized
   – Examples:  cyclic voltammetry, many biosensors