Electrochemistry revolves around the study of chemical changes of particles caused by the movement of electrons from one element to another through redox (oxidation-reduction) reactions. There are a number of techniques that fall under the category of electrochemistry, including: potentiometry, pH measurement, coulometry, voltammetry, polarography and amperometry. All of these utilise an applied current to convert an analyte from one oxidation state to another.
pH measurements are one of the most common type of electrochemistry, as the acid or bases separate into ions in water conducting electricity. Measurement of pH in pure water is problematic due to the low ionic strength of the solution and because the rapid uptake of carbon dioxide to form weak carbonic acid affects the observed readings.
As the technique relies on the sensitive measurement of tiny electrical signals, it is vital that the water used produces minimal interference due to background contamination.
When it comes to the measurement of pH, the buffer is important for accurate measurement as it has a very stable pH which will not change significantly if an acid or a base is added to it. The pH meter measures the differential between two electrodes, one of which is in the reference buffer. It is important that the water used to prepare the buffer is free of impurities which could affect the pH.
Make sure that you are using the right water type for your application. Here are the requirements for electrochemistry applications.
|Sensitivity required||Resistivity |
|Bacteria (CFU/ml)||Endotoxins (EU/ml)||Nucleases||Water grade|
|Electrophysiology||General||>1||<50||<0.2||<1||NA||NA||Type II Water|
Type II Water
Ultrapure Water (Type 1)