Metrohm 2.946.0010, Руководство пользователя

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5 Operation
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37
NOTICE
The addition of KMnO
4
is only required if the sample contains As III
as well as As V . If the sample only contains As V , the determination
can be carried out without the addition of KMnO
4
solution.
5 Position the measuring vessel on the base plate (3- 1 ) of the measur-
ing stand. Fit the measuring head, with scTRACE Gold, stirrer and
transparent ring assembled, in a way that electrode and stirrer
immerse into the solution. Press the measuring head down until the
stop.
6 Start the determination as described in Running a determination
(page 25) .
7 When prompted, add 100 µL As(V) standard solution through one of
the two pipetting openings in the transparent ring
(3-
5
) using a
micro pipette, e.g. 6.01562.010, which is in the scope of delivery.
8 When the determination is finished, remove the measuring head,
with scTRACE Gold, stirrer and transparent ring assembled, empty the
measuring vessel and thoroughly rinse electrode, stirrer and vessel
with ultrapure water.
NOTICE
The example method AB416 Determination As(total).detp has a
linear working range (see chapter 7.4.1, page 60) from approx. 1 µg/L
to 20 µg/L arsenic. If samples with higher concentration should be mea-
sured, the method parameter
Waiting time 1 can be reduced. A dep-
osition time of e.g. 30 s would change the working range to approx. 2
µg/L to 40 µg/L. In this case volume and/or concentration of the stan-
dard solution have to be adapted, too.