5.3 Analysis
Before using the Metalyser
®
to perform a test, ensure that the working electrode has
first been successfully plated and conditioned for the metal of interest.
The complete instructions for each Metal are included in the application notes.
There are two ways to analyse a sample in the field: Single point or Multi-point
Standard Addition procedure. A third procedure using *calibration curve technique
can be carried out, but only in exceptional circumstance - please contact
[email protected] for assistance.
1.
Standard Addition (Single Point):
This is the recommended method of analysis
when using the Metalyser
®
instrument on its own, where the user adds a known
amount of standard to the solution, giving a known peak height. The Metalyser
®
will
first run a scan on the sample, to determine if the metals are present and measure
the response. A prompt will be given to add a standard to the sample; this is done
using the pipette provided. A fixed volume of standard is added to the SAB which
will
produce the increase in peak height from which the initial sample concentration
can
be calculated.
2.
Multi-point Standard Addition:
This is the recommended method when using the
tablet PC and gives more advanced analysis. By selecting the
Analyse Sample
option, an analysis will be run and the results plotted. A standard addition is made to
the sample and the
Analyse Sample
option is run again; this step can be repeated
to produce multiple voltammograms corresponding to different standard additions.
The peak heights can be measured manually (as described in advanced graph
functions, page 30) and the results tabulated using the spreadsheet function. Once
the data has been entered the calculate function can be used to generate a linear
regression curve and determine the result for the original sample concentration.
3. *
Calibration:
This is not the recommended method of use for analysis.
See above
note.
After each analysis, the sonde head and the electrodes are to be washed
thoroughly. This is in order to minimise carry-over and to clean off all traces
of the previous analysis. This can be achieved by using the deionised water
or by washing the sonde head (without the SAB) in the sample water. This is
particularly important following an arsenic analysis.
Metalyser® Field Pro HM3000 Instruction Manual v 5.0
www.trace2o.com
