Metrohm 850 Professional IC Anion MCS Prep 2 - Manual (Page 68)

2.18 Metrohm CO
2
suppressor (MCS)
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850 Professional IC – Anion – MCS – Prep 2
2.18 Metrohm CO
2
suppressor (MCS)
2.18.1 General information on the MCS
The MCS removes the CO
2
from the eluent flow. This reduces the back-
ground conductivity, improves the detection sensitivity and minimizes the
injection and carbonate peaks.
The MCS is used for removing CO
2
from the eluent flow before detection.
CO
2
can reach the eluent flow through the sample itself or arise through
the suppression reaction in the MSM.
The CO
2
peak is effectively minimized through connection of the MCS
between the MSM and detector. The principle is based on the gas perme-
ability of the fluoropolymer membrane inside the degassing cell of the
MCS. The eluent is guided through a capillary with a fluoropolymer mem-
brane inside the degassing cell. A vacuum is generated in the degassing
cell via a pump. At the same time, the pump sucks CO
2
-free air (CO
2
is
removed by a CO
2
adsorption cartridge (33-4)) through the degassing cell.
The pressure and concentration difference in the degassing cell in compar-
ison to the inside of the capillary now causes the CO
2
to diffuse out of the
eluent flow.
2.18.2 Connecting MCS
The MCS is connected between the MSM (see Chapter 2.16, page 50)
and detector.
1 2
3
4 4 5 5
6 7
Figure 32 MCS – connection
1 MCS input
Connection to the MSM. 2 MCS output
Connection to the detector.