Metrohm 850 Professional IC MSM-HC MCS Prep 3 - Manual (Page 60)

3.14 Sample preparation module (SPM)
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850 Professional IC Anion – MSM-HC – MCS – Prep 3
Weak alkaline solutions can directly be forwarded to the SPM as with cat-
ion exchange. However, strong alkaline solutions (e.g. 30 % NaOH) could
exceed the capacity of the SPM. In order to ensure a sufficient capacity for
exchanging the Na
+ ions for H + ions in all cases, only a small part of the
sample (e.g. 20 µL) is therefore given onto the SPM. For measuring the
sample the sample loop of an additional injection valve (27-A) (e.g. on
the Sample Processor) is needed.
Procedure of the neutralization with the SPM
1 Measuring the sample
￭ Valve positions:
– Injection valve 1 (27-A) in position Fill.
– Injection valve 2 (in the instrument) in position Inject.
￭ On the injection valve 1 (27-A) the sample is carried through the
sample loop and is measured.
1 A B
Figure 27 Measuring the sample
1 Sample A Injection valve 1
With sample loop. For measuring the sam-
ple.
B Injection valve 2
With preconcentration column. For precon-
centrating and injecting the analyte ions.
2 Neutralization and preconcentration
￭ Switch both injection valves:
– Injection valve 1 (28-A) to position Inject.
– Injection valve 2 (28-C) to position Fill.
￭ The sample is carried with the transfer solution (28-2) onto the
SPM (28-B).
Na
+ ions are exchanged for H + ions.
￭ The analyte ions and the transfer solution flow to the injection
valve 2.