Static dropping-mercury electrode

Voltammetric measurements were performed with an AIS model DLK-100 voltammetric analyzer and a standard three electrode system consisting of a SCE reference electrode with salt bridge, a Pt counter electrode and a working electrode. In some experiments a solid state Au/Hg microelectrode was used as the working electrode and in others an EG G model 303A static dropping mercury electrode was interfaced to the analyzer. Both the Mn(III) to Mn(II) reduction and the Mn(II) to Mn(0) reduction onto the Hg electrode could be monitored simultaneously. 

Luther et al. (1991) employed square wave voltammetry for the determination of thiosulphate, sulphite and tetrathionate. They used an EG B Princeton Applied Research Model 383B-4 in conjunction with a Model 303 static dropping mercury electrode. 

Mercury electrodes (a) hanging mercury drop electrode (b) dropping mercury electrode (c) static mercury drop electrode. 

A form of voltammetry using a dropping mercury electrode or a static mercury drop electrode. 

Hanging mercury-drop electrode (HMDE) A commonly employed working electrode in polarography. The HMDE is often preferred to the experimentally simpler dropping mercury electrode (DME) because resultant polarograms do not have a sawtoothed appearance and because accumulation (for stripping purposes) is readily achieved at its static surface. 

The following types of mercury electrodes have been widely used for voltammetry dropping mercury electrode (DME), hanging mercury drop electrode (HMDE), static mercury drop electrode (SMDE), streaming mercury electrode (SME), and mercury film electrode (MFE). We begin our discussion with a description of the construction and properties of the DME because this electrode has a long history and continues to be used for both analytical and fundamental studies. 

Note DC = direct current DP = differential pulse SW = square wave DME = dropping mercury electrode SMDE = static mercury drop electrode HMDE = hanging mercury drop electrode TMFE = thin mercury film electrode. 

As the later chapters indicate, a given question concerning a chemical system usually can be answered by any one of several electrochemical techniques. However, experience has demonstrated that there is a most convenient or reliable method for a specific kind of data. For example, polarography with a static or dropping-mercury electrode remains the most reliable electrochemical method for the quantitative determination of trace-metal ion concentrations. This is true for two reasons (1) the reproducibility of the dropping-mercury electrode is unsurpassed and (2) the reference literature for analysis by polarography surpasses that for any other electrochemical method by at least an order of magnitude. 

Fig. IL2.1 Mercury drop area plotted vs. time dme dropping mercury electrode smde static mercury electrode...

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