What is polarographic method?
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Polarography is a voltammetric technique in which chemical species (ions or molecules) undergo oxidation (lose electrons) or reduction (gain electrons) at the surface of a dropping mercury electrode (DME) at an applied potential. Polarography only applies to the DME.
Which detector is used in polarographic method?
Polarography using the dropping mercury electrode has some advantages as a liquid chromatography (LC) detecting system.
What is application of polarography?
Polarography has been used extensively to determine trace metals in pharmaceutical products and to estimate drugs that contain metals as a constituent. The metals examined include antimony, arsenic, cadmium, copper, iron, lead, magnesium, mercury, vanadium and zinc.
What is the principle of polarographic titration?
Principle: Polarography is based upon the principle that gradually increasing voltage is applied between two electrodes, one of which is polarisable (dropping mercury electrode) and other is non-polarisable and current flowing between the two electrodes is recorded.
What are the different types of current in polarography?
Normal polarography has been replaced by different types of pulse polarography (Fig. 6.28), e.g., differential pulse polarography, normal pulse polarography, staircase polarography, and square-wave polarography. Here, limiting and peak currents are in linear relationship with analyte concentration.
What are the advantages of using dropping mercury electrode?
A major advantage of the DME is that each drop has a smooth and uncontaminated surface free from any adsorbed analyte or impurity. The self-renewing electrode does not need to be cleaned or polished like a solid electrode. This advantage comes at the cost of a working electrode with a constantly changing surface area.
What is the difference between polarography and voltammetry?
The key difference between polarography and voltammetry is that the polarography is a type of voltammetry that uses a liquid metal electrode whereas the voltammetry is an analytical technique in which the potential is varied regularly while the current is monitored. Polarography is a subclass of voltammetry.
Why dissolved oxygen is removed before polarographic analysis?
Since it can be present in solutions in high concentrations and since it is electroactive, oxygen must be removed from the analyte prior to polarographic analysis. Problems arise both from the voltammetric behavior of oxygen itself and form the associated chemical reactions that take place.
What is the full name of DME in polarographic cell assembly?
The dropping mercury electrode (DME) is a working electrode made of mercury and used in polarography.
What is the role of polarography in electrochemistry?
Polarography may be used simply as an analytical tool or as a diagnostic method to interpret mechanisms and rates of electrode chemical reactions. Electrode surface redox reactions may occur with both inorganic and organic chemical species, although this article will deal solely with the inorganic applications of polarography.
What is the polarographic method?
The polarographic method was defined by the inventor as electrolysis with a polarizable dropping mercury electrode (DME) and it gained rapid acceptance not only in the investigation of electrode processes but, particularly, as a very important analytical technique.
What is the use of Polarity analysis in organic chemistry?
Polarography technique is employed in organic chemistry for qualitative and quantitative analysis and structure determinations of organic compounds. Since the organic compounds are insoluble in pure aqueous medium the solvent in which the organic compound and its electrode product is soluble is added to the supporting electrolyte.
What is the application of a polarogram?
Polarography is used widely employed for the analysis of trace metals in the alloys including ultra-pure metals, minerals/metallurgy, environmental analysis, foodstuffs, beverages and body-fluids, toxicology and clinical analysis.