Metrohm 850 Professional IC Anion MCS Prep 3 - Manual (Page 54)

2.14 Sample preparation module (SPM)
￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭
44 ￭￭￭￭￭￭￭￭
850 Professional IC –Anion – MCS – Prep 3
Weak liquors can directly be forwarded to the SPM as with cation
exchange. However, strong liquors (e.g. 30 % NaOH) could exceed the
capacity of the SPM. In order to ensure a sufficient capacity for exchang-
ing 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(26-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 (26-A) to position Fill.
– Injection valve 2 (in the instrument) in position Inject.
￭ On the injection valve 1 (26-A) the sample is carried through the
sample loop and is measured.
1 A B
Figure 26 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 (27-A) in position Inject.
– Injection valve 2 (27-C) to position Fill.
￭ The sample is carried with the transfer solution (27-2) onto the
SPM (27-B).
Na
+ ions are exchanged for H + ions.
￭ The analyte ions and the transfer solution flow to the injection
valve 2.