Metrohm viva 1.0 (process analysis) - Manual (Page 971)

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Glossary
viva 1.0 (for Process analysis)
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Sample measurement
The suppressor concentration in the sample is determined under the same
conditions used for the calibration, with the difference that sample solu-
tion and not the suppressor standard solution is added to the basic solu-
tion. Once the Evaluation ratio has been achieved, the suppressor con-
centration in the sample is calculated from the determined effective addi-
tion volume with the help of the previously determined calibration fac-
tor (see Chapter 5.6.7.7.20, page 638).
Example
The example shows the calibration curve for the standard (gray) and the
measurement curve for the sample (blue) with the values determined for
the effective addition volume VEFF(STD) = 74.8 µL and VEFF(SMPL) =
147.44 µL for the evaluation ratio Q/Q(0) = 0.5.
Dilution volume
If a sample is diluted, then the dilution volume refers to the entire volume
of sample and dilution solution. Of this diluted sample, the analysis vol-
ume (see Glossary, page 956) is then added to the measuring vessel (see
Glossary, page 963).
Effective addition volume
In order to avoid nonlinearities in the calculation of the regression data, a
quantity must be found that exhibits a direct correlation between the
measured quantity and the x axis of the calibration curve. Usually, this
quantity is the concentration. In the calibration method DT (see Glossary,
page 958), however, the concentration of the sample is what is being
investigated. The problem is that only the addition volume (i.e. the addi-
tion volume of the standard solution during calibration and the addition
volume of the sample during sample determination) is known.