What is principle of polarographic method of analysis?
The simple principle of polarography is the study of solutions or of electrode processes by means of electrolysis with two electrodes, one polarizable and one unpolarizable, the former formed by mercury regularly dropping from a capillary tube.
What is polarography and its application?
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.
Which detector is used in polarographic method?
OxyFerm. The OxyFerm polarographic dissolved oxygen sensor is specifically suited for hygienic applications in the pharmaceutical industry. The OxFerm CIP is designed to withstand frequent CIP cleaning procedures.
Why is polarography used?
The majority of the chemical elements can be identified by polarographic analysis, and the method is applicable to the analysis of alloys and to various inorganic compounds. Polarography is also used to identify numerous types of organic compounds and to study chemical equilibria and rates of reactions in solutions.
What is the objective of polarography?
Polarography is an electroanalytical technique that measures the current flowing between two electrodes in the solution (in the presence of gradually increasing applied voltage) to determine the concentration of solute and its nature respectively.
Why DME is used in polarography?
In polarography, DME is used as a working electrode. DME stands for dropping mercury electrode. In this electrode, mercury is the main constituent because it can be renewed after each drop of its usage as mercury is liquid. The surface remains contamination-free and pure, unlike solid electrodes.
Which of the following is advantages of polarography?
The major advantages using polarography for inorganic analysis may be summarized: (1) comparatively inexpensive equipment is required, (2) ability of the technique to distinguish between elemental oxidation states (i.e., Cr, As), (3) ability of the technique to establish the chemical form of elements (e.g..
Who discovered polarography?
Jaroslav HeyrovskýPolarography / Inventor
Why mercury is used in DME?
The pool of mercury acts as a counter electrode, i.e., anode if DME is the cathode or cathode if DME is the anode. The counter electrode is a non-polarisable electrode. To the analyte solution, an electrolyte like KCl is added i.e., 50-100 times of sample concentration.
What is polarography explain?
Polarography is an instrumental method of chemical analysis used for qualitative and quantitative determinations of reducible or oxidizable substances. Heyrovský’s instrument measures the current that flows when a predetermined potential is applied to two electrodes immersed in the solution to be analyzed.
How many types of electrodes are there in polarography?
Types of Mercury Electrodes Used in Polarography There are three types of electrodes: 1. DME (Dropping Mercury Electrode): The mercury drop forms at the end of the capillary through gravity.
What is the method of polarography?
Polarography is an electrochemical method based on electrolysis with a dropping mercury electrode (or with some other types of mercury electrodes, with a periodically renewed surface).
What determines the shape of a polarogram?
The shape of a polarogram depends on the method of analysis selected, the type of indicator electrode used, and the potential ramp that is applied. The Figure shows five selected methods of polarography; the potential ramps are applied to a mercury indicator electrode, and the shapes of the resulting polarograms are compared.
What is the working electrode of a polarogram?
Polarography is a type of voltammetry where the working electrode is a dropping mercury electrode (DME) or a static mercury drop electrode (SMDE), which are useful for their wide cathodic ranges and renewable surfaces. It was invented in 1922 by Czech chemist Jaroslav Heyrovský, for which he won the Nobel prize in 1959.
What is the difference between voltammetry and polarography?
The several forms of voltammetry differ in the type of varying potential that is applied to the indicator electrode. Polarography is voltammetry in which the indicator electrode is made of mercury or, rarely, another liquid metal. In classic polarography, mercury drops from a capillary…. Jaroslav Heyrovský.