Operation
inoLab pH/ION 735
56
4.5.10 Standard addition with blank value correction (
Blank add.
)
In the "Standard addition with blank value correction" procedure, a
known amount of standard solution is added to the sample in two steps.
With the first addition, the ion concentration is raised to the linear range
of the electrode characteristic curve.
The second addition is equivalent to the standard addition.
The ion concentration in the sample is calculated from the change in
potential.
Measuring
1
Select the measuring method (see section 4.5.5).
2
Prepare two standard calibration solutions.
3
Perform a two-point calibration according to the user guidance.
4
As soon as a stable value is achieved for the second standard
calibration solution, the slope (mV) and evaluation (+ ... +++) of
the electrode after calibration is displayed.
i
Slope =
33.6 mV
i
Sensor
+++
Accept
ISE <CAL>
5
Start the measurement with
g
An entry window appears.
6
Thoroughly rinse the electrode with deionized water.
7
Immerse the electrode in the sample that was supplemented
with blank value solution.
i
Immerse sensor in sample
Sample volume
100.0 ml
ISA/TISAB vol.
1.0 ml
BV volume
100.0 ml
BV concentration
1.000 mg/l
Continue
Blank value addition
