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2 operation, 1 supply bottle, 2 aspiration filter – Metrohm 850 Professional IC Anion MCS Gradient User Manual

Page 81: 3 changing the eluent, 5 high pressure pump, 1 protection, Operation, High pressure pump, Protection

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4 Operation and maintenance

850 Professional IC –Anion – MCS – Gradient

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71

4.4.2

Operation

4.4.2.1

Supply bottle

The supply bottle with the eluent must be connected as indicated in Chap-
ter 2.8.1, Page 26
. This is above all important for eluents with volatile sol-
vents (e.g. acetone).

Moreover, condensation must also be prevented in the eluent bottle. Drop
formation can change the concentration ratio in the eluent.

4.4.2.2

Aspiration filter

To protect the IC system against foreign particles, we recommend aspirat-
ing the eluents via a 6.2821.090 aspiration filter (12-2). This aspiration fil-
ter must be replaced should it show signs of yellow discoloration (but no
later than every 3 months).

In the case of very sensitive measurements, the eluent should be stirred
constantly with a magnetic stirrer.

4.4.2.3

Changing the eluent

When changing the eluent, it must be ensured that no precipitates can
occur. Solutions following one another in direct succession must therefore
be miscible. If the system has to be rinsed organically, several solvents
with rising or falling lipophilia must be used.

4.5

High pressure pump

4.5.1

Protection

Caution

The pump head is filled ex works with methanol/ultra pure water. It
must be ensured that the eluent used is freely miscible with the solvent
remaining in the pump head.

To protect the high pressure pump against foreign particles, we recom-
mend that the eluent undergoes a microfiltration (filter 0.45 µm) before
being aspirated via a 6.2821.090 aspiration filter (see "Assembling eluent
aspiration tubing", page 26)
.

Salt crystals between the piston and seal cause abrasion particles which
can find their way into the eluent. These lead to contaminated valves, a
rise in pressure and in extreme cases scratched pistons. It is therefore
essential to ensure that no precipitates can occur (see Chapter 4.4.2.3,
page 71)
.