Metrohm 790 Personal IC - Manual (Page 46)

2.8 Suppressor module
790 Personal IC
37
2.8 Suppressor module
2.8.1 General information on suppressor module
The Metrohm Suppressor Module MSM for chemical suppression
installed in the 2.790.0020 Personal IC comprises a total of 3 suppres-
sor units which are in turn used for suppression, regenerated with sulfu-
ric acid and rinsed with water. To record every new chromatogram un-
der comparable conditions, work is normally carried out with freshly
regenerated suppressor. Switching is either automatic together with the
valve switching or manual.
The suppressor units must never be regenerated with H
2
SO
4
in the
same flow direction used for the eluent. You should thus always install
the inlet and outlet capillaries as described in section 2.8.4 according
to the scheme shown in Fig. 16.
For operation of the suppressor module, the
two-channel peristaltic
pump built into the 2.790.0020 Personal IC is used which conveys the
regeneration solution (normally 20 mmol/L H
2
SO
4
) and the rinsing so-
lution (normally dist. H
2
O) to the suppressor units (flow rate of
0.5 mL/min).
The three inlets and outlets numbered 1...3 on the suppressor module
each have 2 permanently mounted PTFE capillaries, which must be
connected as described in section 2.8.4 (see Fig. 15 and Fig. 16).
To avoid contamination of the suppressor module by foreign particles
or bacterial growth, the two 6.2821.100 Filter units PEEK (see sec-
tion 2.3.5) supplied with the 2.790.0020 Personal IC must be installed
between the peristaltic pump and the inlet capillaries of the suppressor
module.
The suppressor module must never be switched in the dry state as
there is a danger of blocking. Before every switching operation of the
suppressor module, the three suppressor units must have been
rinsed for at least ½ h with eluent, regeneration and rinsing solution.
2.8.2 Preparation of the peristaltic pump
Before start-up the accessories for the 2-channel peristaltic pump built
into the 790 Personal IC must be mounted according to Fig. 14. Pro-
ceed as follows:
1 Attach pump tubings
• Loosen both tubing cartridges 40 40 40 40 mounted above pump
drive 44 44 44 44 from the holding clamp 42 42 42 42 by pressing down snap-
action lever 43 43 43 43 and remove from mounting pin 45 45 45 45 (see Fig.
15).