Cadmium is a natural element, that is highly toxic to humans and animals. Small quantities of cadmium are suspected to cause adverse changes in arteries, human kidneys, and has also been linked to certain cancers. Cadmium may enter natural water from industrial discharges or the deterioration of galvanized pipes Cadmium is used as an electrode component in alkaline batteries, pigments, coatings, and platings, and as a stabilizer for plastics.
Cadmium ion-selective electrodes (ISE) are used to rapidly determine the amount of free cadmium ions in samples, and as a detector for the titration of cadmium with EDTA. Cadmium sensors are “electrodes of the third kind” because they detect cations that also form low-solubility salts with sulfide anions and with silver.
The following products include portable and benchtop ISE meters that can display cadmium results in a choice of concentration units. Other products include calibration standard, ISA and polishing strips for the halide solid state pellet.
Below are the most common products used for measuring cadmium.
Benchtop pH/ISE meters
Benchtop pH/ISE meters include a two channel option in which a pH probe can be connected to one channel and the bromide ISE to the other. The benchtop meters have the ion charge and formula weight pre-programmed for use with the bromide ISE. The benchtop meters also have incremental methods pre-programmed, including the known addition, known subtraction, analyte addition, and analyte subtraction methods.
Portable pH/ISE Meters
Portable pH/ISE allow the flexibility to perform an ISE measurement in labs with limited bench space and can be stored relatively easily. Two models are available including one dedicated to the fluoride measurement while the other can accept other ISEs and has the ion charge and weight pre-programmed for the specific parameter.
Ion Selective Electrode
The cadmium ISE is a solid state electrode available as either a single half-cell or combination design that is complete with a reference cell. These electrodes incorporate a solid sensing surface.
Solutions for cadmium measurement include an ISE standard and ISA for calibration and measurement. Other solutions include the fill solution that is used with the ISE.
Accessories include halide polishing strips and magnetic stirrers to ensure adequate mixing when using an ISE.