Amperometric Titration and Redox Analysis

Amperometry is an electrochemical technique that measures current at a constant applied voltage. It's used in quantitative analysis to determine the endpoint of a reaction by measuring the current changes occurring during titration.

In amperometric titration, the voltage between an indicator electrode and a reference electrode is kept constant. The current flowing through the cell is measured as the titrant is added.

The potential applied should be set at a value where the indicator electrode produces a diffusion current. This means that the potential should be sufficiently high to ensure that all electroactive species are reduced at the electrode.

A dropping mercury electrode (DME) is often used as the indicator electrode for amperometric titration. This electrode generates a constant stream of mercury droplets, which act as the working electrode.

A rotating platinum micro-electrode is another type of electrode used in amperometric titration. This electrode consists of a platinum wire rotating at a constant speed to provide a fresh surface for the electrochemical reaction.

A saturated calomel electrode (SCE) is commonly used as the reference electrode in amperometric titration. It provides a stable and reproducible potential against which the potential of the indicator electrode is measured.

Amperometric titration offers advantages over other methods, including its high sensitivity, ease of use, and ability to analyze complex samples.

Amperometric titration is used in a wide range of applications, including pharmaceutical analysis, environmental monitoring, and food chemistry to determine the concentration of various species.

A rotating platinum micro-electrode (RPME) is an electrochemical sensor used in various analytical techniques. It is a small platinum wire that rotates at a constant speed in a solution, providing a consistent surface area for electrochemical reactions. RPME offers advantages over the traditional dropping mercury electrode (DME) by enabling measurements at positive potentials and providing higher diffusion currents.

RPMEs overcome the limitations of DME by allowing for measurements at positive potentials, where mercury would oxidize. This is due to platinum's higher resistance to oxidation.

RPME generates a much larger diffusion current compared to DME. This allows for the detection of very low concentrations of ions in a solution.

Amperometric titration is a quantitative analytical technique that uses the change in current at a working electrode to determine the concentration of an analyte.

In this type of amperometric titration, an analyte ion that can be reduced (loses electrons) is titrated against a non-reducible ion. As the analyte is consumed, the current decreases until it reaches an endpoint.

This amperometric titration involves the use of a non-reducible analyte ion to titrate a reducible ion. The current increases with the addition of the titrant until the endpoint is reached.

Amperometric titrations are beneficial as they can analyze dilute solutions and work with both reducible and non-reducible ions. The setup is simple, reducing the need for complicated equipment or temperature control.

Amperometric titration plays a vital role in quantitative analysis, helping determine the endpoint of reactions and measuring ion concentrations. It is often used in analyzing water content using the Karl Fischer reagent.