Electroanalytical Techniques Principles and

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Electrochemistry is the relationship between electrical properties and chemical substances in reactions. In its application to analytical chemistry, this generally involves the measurement of some electrical property under conditions which, directly or indirectly, allow an association between the magnitude of the property measured and the concentration of some particular chemical species. Such measurements are nearly always made in solution environments. The electrical properties that are most commonly measured are potential or voltage, current, resistance or conductance, or combinations of these. In some instances the electrical property may be a function of time, whereupon time may also be a variable to be measured. Capacitance is a property which, although not usually measured, has influence in polarographic or voltammetric analysis and requires consideration. 

Electrochemical methods of analysis have grown greatly in application and importance over the last 40 years, and this has been largely due to the development and improvement of electronic systems permitting refinements in the measurement of the critical characteristics mentioned in the foregoing. In addition to this, the measurement systems and the advanced electronics now permit much of the work in electroanalytical chemistry to be automated and controlled by microprocessors or computers. Some electroanalytical techniques have become very widely accepted others, such as polarography/voltammetry, less so. This has been due to early problems with equipment. Despite the fact 

Electrochemistry and electroanalytical chemistry are usually covered in undergraduate courses in physical chemistry and in instrmnental methods of chemical analysis. There are a number of different modes of electrochemical approach to chemical analysis. For this reason, the associated theory and the range of applications are best left to be discussed separately for the individual approach. 

The order of presentation of the electroanalytical methods will be direct potentiometry with ion-selective electrodes, potentiometric titrations, voltammetry/polarography, polarisation titrations (amperometric and potentiometric), conductometry/coulometry and electrochemical detectors. 

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