Mercury electrode: advantages analysis

By far, most of electrochemical kinetic data that can be subjected to detailed analysis has been obtained at the mercury-aqueous electrolyte interface or at mercury electrodes in other solvents (1-4.16L The main advantages of mercury over other... 

Among great advantages of the use of bismuth film electrodes we can highlight the capability of bismuth to make a fuse allow [42], what makes the film as applicable as the mercury electrodes for pre-concentration of metals. Once the film is formed, its performance can be compared to those for mercury electrodes for several metal analysis [43-46]. Figure 7 shows an example of an application of the BiFE for analysis of some metals in sugar cane. 

Stripping analysis with inherent pre-concentration seems attractive to CFA, but until recently such a procedure appeared rather exceptional. It has been used in the automatic determination of heavy metals in water by anodic stripping voltammetry (ASV12S) in a continuous flow cell with a mercury-covered graphite electrode, having the advantage that one can distinguish... 

Owing to the toxicity of mercury and its disposal problem, solid electrodes are now very popular. In particular, electrodes made of carbon such as glassy carbon, graphite, carbon paste, and carbon fibers have gained popularity. Mercury, gold, bismuth, and other metals can be deposited as thin metal films on carbon and serves as thin metal film electrodes (TMFE) with excellent analytical advantages in trace metal analysis. The choice of working electrode is determined by the redox... 

Taking advantage of the ability to detect multiple group II and group III metals at mercury film electrodes using stripping analysis, a multianalyte DNA sensor was developed using different semiconductor nanocrystals (ZnS, CdS, and PbS) for the... 

Quasi-reference electrodes can be employed in situations where the high reproducibility of potential is not necessary, such as in many voltammetric analysis experiments. Mercury pools (referred to above) or silver wires in aqueous halide media are examples. Platinum wires can also be used. The advantage of wires, apart from their small size, is in reducing the uncompensated resistance in resistive media, relative to conventional reference electrodes. 

DNA, RNA, and protein-modified electrodes can be prepared using both carbon and mercury surfaces [283]. Stability of immobilization of NAs at HMDE and graphite electrodes is very good [270]. AdTSV has been widely applied to various kinds of NA and protein studies [13, 15, 249, 270, 281, 284, 285]. Compared with conventional voltammetry, AdTSV has many advantages that are mainly due to the separation of the biomacromolecule adsorption from the electrode processes. These advantages include (1) reduction of the sample volume to 3 to 10 microliters, (2) elimination of interferences by low molecular mass substances that are washed off in AdTSV, (3) adsorption of the biomacromolecule on the electrode from media not suitable for the conventional voltammetric analysis, (4) in studies... 

Potentiometric stripping analysis (PSA) is another commonly used technique in water analysis. This technique can usually be applied directly to the analysis of water samples without previous treatment, and it is virtually free from interferences of dissolved oxygen. Both, PSA and ASV techniques are based on the same principle the anal) e is first deposited on the electrode surface while the solution is stirred, and then stripped back to the solution in the measurement step [14,22,196]. The ASV technique works on a film electrode (electrochemically deposited mercury or gold on a glassy carbon support). One advantage of PSA is that it requires simpler equipment than ASV, and can compete with nonelectroanalytical techniques in terms of price, and possibility of automation [247-249]. This method has been applied to determine metals in tap water and rainwater samples [250-253], coupled with FIA to determine copper in natural waters [254,255], etc. In addition, portable PSA instruments have also been developed, and demonstrated to be useful for metals determination in aquatic samples [256-259]. 

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