The Scanning Analyzer SA-5000 system uses the electrochemical technique of stripping
analysis to specifically determine the concentration of lead in a solution. Anodic
stripping analysis is a two step process. The first step is called the deposition step
and involves the electro-deposition of lead on to a disposable mercury-film electrode.
The deposition is achieved by cathodic deposition at a fixed potential and time.
Following the fixed deposition time, the system enters the second step, the stripping or
measurement step. The stripping step involves scanning the potential anodically using a
potential-time waveform. During this anodic scan the deposited lead is reoxidized and
stripped out of the electrode. The current and potential are measured during the anodic
scan and the resulting voltammogram contains a peak whose potential is specific to lead
and whose height is proportional to the concentration of lead in the solution. The peak
height is converted from a current to a concentration using one of many calibration curves
stored in the instrument. No user calibration is required because each batch of
electrodes is checked during manufacture and assigned an eight figure calibration code.
The calibration code is used to select the calibration curve which matches the electrode
batch. Reporting limits during this verification test were 25 :g/wipe.
For more information from the manufacturer, click here: http://www.palintest.com