A complete low cost, sensitive analytical solution for the determination of cadmium in effluent waters using the Metrohm 797 VA Computrace with UV sample digestion
Cadmium is a metal found in natural deposits as ores containing other elements.
Its greatest use is probably from metal plating and other associated coating operations but low levels are found naturally in certain foods and it is one of the ingredients of cigarette smoke.
Cadmium is a known carcinogen and can accumulate in the kidneys and repeated long term exposure can possibly cause kidney failure and ultimately can lead to death.
The need to quantify and regulate cadmium releases is thus very important from an environmental and also legislative prospective.
Cadmium compounds are able to leach through soils to ground waters and bind to sediments of rivers.
These sediments can be bio-accumulated when disturbed and cause problems for certain aquatic life.
The cadmium content can easily and reliably be measured in effluent (and any other) waters using the Metrohm 797 VA Computrace and 705 UV digester to provide a complete analytical solution for the analysis of cadmium and many other transition metals.
The UV digestion unit is used in those instances where the organic sample matrix interferes with the electrochemical determination.
In recent years voltammetry has undergone a tremendous renaissance and for the analysis of water samples is fast becoming the technique of choice as it is not affected by particulate or saline samples that can cause problems for spectroscopic methods.
The digested effluent water sample and auxiliary solution were added to the reaction vessel and the cadmium determined using adsorptive stripping voltammetry with the patented Metrohm Multi Mode Electrode (MME).
A typical effluent release was analysed and found to contain 0.9ug/l of cadmium demonstrating perfectly the sensitivity of voltammetry for a fraction of the purchase and just as importantly the running costs of spectroscopic techniques.
Calibration is performed on each and every sample using the technique of standard addition that takes into account any background matrix effects.
In addition to the determination of cadmium, zinc, lead and copper can also be determined in the same sweep.
