Metrohm 850 Professional IC Anion - Manual (Page 52)

2.14 Injection valve
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42 ￭￭￭￭￭￭￭￭
850 Professional IC – Anion
1 2
4 5
3 6
1 2
4 5
3 6
1 2
4 3
5
4 3
1 2
A B
Figure 24 Injection valve – Positions
A Position FILL B Position INJECT
1 Eluent input
Capillary coming from the high pressure
pump. 2 Eluent output
Capillary to the column.
3 Sample input
Sample aspirating capillary. 4 Sample output
Capillary to waste container.
5 Sample loop
Position A In the position FILL, the sample solution flows
through the sample loop to the waste container.
The eluent flows directly to the separation col-
umn at the same time.
Position B In the position INJECT, the eluent flows through
the sample loop to the separation column. If
sample solution is to be found in the sample
loop at the time of the valve switchover, then
this will be conveyed along with the eluent, thus
making its way to the separation column. The
flow in the sample path is either stopped or the
sample flows directly to the waste container.
2.14.3 Selecting the sample loop
The amount of sample solution injected depends on the volume of the
sample loop. The choice is made on the basis of the application. The fol-
lowing sample loops are normally used:
Cation determination 10 µL
Anion determination with suppression 20 µL
Anion determination without suppression 100 µL