Potentiometry basic techniques

Just as in aqueous solutions, potentiometry is the most fundamental and powerful method of measuring pH, ionic activities and redox potentials in non-aqueous solutions. Here we deal with the basic techniques of potentiometry in non-aque-ous solutions and then discuss how potentiometry is applicable to studies of chemistry in noil-aqueous solutions. Some topics in this field have been reviewed in Ref. [1],... 

In order to determine the stability constants for a series of complexes in solution, we must determine the concentrations of several species. Moreover, we must then solve a rather complex set of equations to evaluate the stability constants. There are several experimental techniques that are frequently employed for determining the concentrations of the complexes. For example, spectrophotometry, polarography, solubility measurements, or potentiometry may be used, but the choice of experimental method is based on the nature of the complexes being studied. Basically, however, we proceed as follows. A parameter is defined as the average number of bound ligands per metal ion, N, which is expressed as... 

This article provides some general remarks on detection requirements for FIA and related techniques and outlines the basic features of the most commonly used detection principles, including optical methods (namely, ultraviolet (UV)-visible spectrophotometry, spectrofluorimetry, chemiluminescence (CL), infrared (IR) spectroscopy, and atomic absorption/emission spectrometry) and electrochemical techniques such as potentiometry, amperometry, voltammetry, and stripping analysis methods. Very few flowing stream applications involve other detection techniques. In this respect, measurement of physical properties such as the refractive index, surface tension, and optical rotation, as well as the a-, //-, or y-emission of radionuclides, should be underlined. Piezoelectric quartz crystal detectors, thermal lens spectroscopy, photoacoustic spectroscopy, surface-enhanced Raman spectroscopy, and conductometric detection have also been coupled to flow systems, with notable advantages in terms of automation, precision, and sampling rate in comparison with the manual counterparts. 

Potentiometry has been used for electroanalytical purposes for many years. In biosensing in particular, this technique is based on ion-selective electrodes and ion-sensitive field effect transistors. Basically, the setup of a potentiometric measurement presents an indicator and a reference electrode (connected to the two terminals... 

In the following paragraphs the basic setups for the measurements are described more details can be found in the various chapters dealing with specific measurement arrangements, such as potentiometry (Chap. 9) or controlled potential techniques (Chap. 10). Numerous books on electroanalytical chemistry may provide deeper insight into the problematic thus, citations here are arbitrary and incomplete. ... 

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