Introduction to Electrolytic Methods of Analysis
- review of electrolytic cells
- selective electrolysis in a mixture of electroactive species
- definition of working and counter electrodes
- a brief overview of the bulk electrolytic methods
of analysis: coulometry & electrogravimetry. Advantages compared to
other titrimetric and gravimetric methods.
Electrode Polarization in Electrolytic Cells
- i-E plot showing electrode polarization in an electrolytic cell
- types of electrode polarization: mass-transfer (concentration) and
- mass transfer of ions in an electrolytic cell: convection, diffusion,
- reduction/elimination of analyte ion migration in electrolytic cells.
General Principles of Voltammetry
- Fick's First Law of Diffusion, and its importance in voltammetry
- Clark oxygen electrode (an amperometric sensor) and how it works.
Factors affecting the signal.
- generalization of the Clark electrode to voltammetry: controlled variable,
measured variable, effect of analyte concentration, other factors that
can affect measurement
Voltammetry Signal Theory
- hydrodynamic voltammetry. Origin of stagnant "depleted"
layer of analyte. Effect of analyte on limiting current.
- effect of WE potential on current: voltammograms in hydrodynamic voltammetry
- diffusion-limited current for a planar WE in unstirred solution: the
Electrodes in Voltammetry
- types of electrodes used in voltammetry
- 3-electrode potentiostat to control WE during electrolysis
- Hg drop electrodes: HMDE, DME and SMDE
- advantages of Hg drop electrodes
- diffustion-limited current for a DME in an unstirred solution: the
- Faradaic and non-Faradaic currents in polarography
- advantage of SMDE over the DME
- basic types of polarography: DCP, sampled DCP, NPP, DPP
- square-wave voltammetry
- principles of stripping voltammetry
- comparison of methods in terms of precision and sensitivity