Metrohm 872 Extension Module Suppression - Manual (Page 41)

￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭ 5 Handling and maintenance
872 Extension Module Suppression ￭￭￭￭￭￭￭￭ 33
1
2
3
4
5
Figure 11 Components
1 Union nut 2 Connecting piece (6.2835.010)
3 Rotor 4 Housing
5 Slot in the housing
5.4.4.2 Regenerating the suppressor
If the suppressor units or the neutralization units of the SPM are loaded
for a longer period with certain heavy metals (e.g. iron) or organic impuri-
ties, these can no longer be completely removed with the standard regen-
eration solution. The capacity of the suppressor units is consequently
affected, which can result in reduced phosphate sensitivity in less serious
cases and a significant rise in the baseline in more serious cases. The neu-
tralization units of the SPM react to contamination with a reduced verifica-
tion sensitivity.
If such capacity or sensitivity problems occur at one or more positions, all
suppressor units or neutralization units must be regenerated wit one of
the following solutions::
￭ Contamination with heavy metals:
1 mol/L H
2
SO
4
+ 0.1 mol/L oxalic acid
￭ Contamination with organic cationic complexing agents:
0.1 mol/L H
2
SO
4
/ 0.1 mol/L oxalic acid / acetone 5%
￭ Severe contamination with organic substances:
0.2 mol/L H
2
SO
4
/ acetone ≥ 20%
Caution
The pump tubings made of PVC must not be used for rinsing with solu-
tions containing organic solvents.
We recommend to use the high pressure pump for regeneration.