Electrochemical instrumentation, early

Not all techniques that at one time showed promise eventually achieved widespread application. An example is coulometric titrimetry, whose history has been discussed.113 Reviews have also appeared of electroanalytical chemistry in molten salts114 and of the early years of the relatively new technique of spectroelectrochem-istry.115 The development of electrochemical instrumentation from its origins, through the electronic age to the computer age has been discussed.116... 

A My research group did a lot to advance the art of electrochemical instrumentation. The early 1980s... 

The early history of electrochemical instrumentation could be said to have begun shortly after the discovery of electricity by Galvani in... 

During the early history of electrochemical instrumentation, much of the work was directed more towards understanding the chemistry involved, rather than the development of instrumentation. By the 1920 s, however, scientists confronted by the limitations of existing techniques, particularly the fact that they were manual and required considerable skill to operate, sought to exploit the newly available electromechanical technology. One of the first improvements to arise was instruments that could automatically record an experiment. 

The work described above provided the technical information for which the CMT method had been developed, while various details of the instrumentation and programming were improved. However, it became obvious at an early stage that there is very rarely agreement between CMT and electrochemical measurements, even if the two are recorded simultaneously. The reliability of the CMT measurements has been tested in several cases (see Refs. 2 and 13, for example), where a sufficient amount of metal had been dissolved during an experiment. Analysis of the cell solution has then in most cases agreed very closely with the result according to the CMT measurements (the total amount of acid used in the experiment is displayed on the autoburet). 

In early 1983, Bioanalytical Systems introduced a new class of integrated processor-driven instrumentation based on a concept first developed by Faulkner and his co-workers [1] at the University of Illinois. This unit (Figs. 6.22 and 6.23) has evolved over the years and now includes a repertoire of some 35 electrochemical techniques, including the most popular large-amplitude (Chap. 3) and small-amplitude (Chap. 5) controlled-potential methods. The unit also is capable of determining electrocapillary curves and can automatically measure and compensate for solution resistance (R in Fig. 6.5). Thus in a single instrument it is possible to utilize virtually all of the diagnostic criteria introduced in Chapters 3 and 5 and also to explore quickly which technique is optimum for... 

Several books on classical electrochemistry had already appeared about 30 to 40 years before the present book was written, for example. Electrochemical Kinetics by K. Vetter, in 1958, and Modern Electrochemistry by O. Bockris and A. Reddy in 1970. In the latter book a wide-ranging description of the fundamentals and applications of electrochemistry is given, whereas in the former the theoretical and experimental aspects of the kinetics of reactions at metal electrodes are discussed. Many electrochemical methods were described by P. Delahay in his book New Instrumental Methods in Electrochemistry, published in 1954. From the mid-1950s to the early 1970s there was then a dramatic development of electrochemical methodology. This was promoted by new, sophisticated electronic instruments of great flexibility. About 20 years ago, in 1980, Bard and Faulkner published the textbook Electrochemical Methods, which is an up-to-date description of the fundamentals and applications of electrochemical methods. ... 

Various electrochemical methods have been appfied for the analysis of NAs, including DPP [5, 11] and DPV[13, 269, 270], linear sweep and CV [13, 271] square wave [138] and a.c. voltammetry [272-274], and recently constant current chronopotentiometry [249, 255-257, 275, 276] and elimination voltammetry [139, 277-279]. DPP was applied for the analysis of DNA in 1966 [280], and in a short time, it replaced OP and d.c. po-larography used in the early NA studies [4, 5]. The main advantage of DPP is its better sensitivity and resolution of peaks. Calf thymus ssDNA produced a well-developed DPP peak III (Fig. 6d) at concentrations of about 10 to 20 igml while dsDNA was inactive at the same concentration. At higher concentrations (hundreds of pgml ), dsDNA produced peak II at potentials by about 70 mV more positive than peak III (Fig. 6c). For years, DPP was the most sensitive instrumental method of determination of traces of ssDNA in dsDNA samples [5]. 

As amply demonstrated by the early workers, it is possible to carry out a preparation electrochemically with little other than a suitable electrolysis cell and a source of power such as a battery. The situation is quite different in fields such as analytical or physical chemistry instrumentation becomes important, and may be a controlling factor (2 ). A basic requirement is the ability to measure electrical quantities such as potential, current, and resistance or conductance. 

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