Drifting Baseline - Thermo Scientific Dionex Chemically Regenerated Suppressor 500 Series Product Manual

4 – Troubleshooting Guide
B. Check for eluent flow out of the suppressor ELUENT OUT port.
!
Do NOT attempt to disassemble the Dionex Chemically Regenerated Suppressor!
CAUTION
C. Remake the regenerant to be sure that the concentration is correct and that the solution
D. Remake the eluent to be sure that the concentration is correct. Be sure that chemicals of
E. If the background conductivity remains high, and you cannot solve the problem on

4.3 Drifting Baseline

If the baseline drifts steadily upward, increase the regenerant flow rate, or if using DCR Mode
increase the regenerant concentration to reduce the background conductivity. As the background
conductivity decreases, the baseline usually levels.
Thermo Scientific
031727-07
1. If there is no flow out of the Dionex CRS 500 ELUENT OUT port, make sure that
eluent is entering the suppressor at the ELUENT IN port. If there is no flow at this
point, trace the eluent flow path backward through the system to find
the blockage.
2. If there is flow of eluent into the Dionex CRS 500 but not out, and there are no
visible leaks from the side seams of the suppressor, a break in the o-ring seal or the
membrane is probably allowing eluent to leak into the regenerant. If this is the
case, then the Dionex CRS 500 must be replaced.
3. If there is flow from the ELUENT OUT port, but no eluent suppression, the
membrane may have been contaminated. Try to restore system performance by
cleaning the membrane (see Section 5, "Suppressor Cleanup").
has been freshly prepared. Be sure that chemicals of the required purity were used to
make the regenerant (see Section 3.1, "Chemical Purity Requirements"). If the
regenerant concentration is too high or too old, it can cause high background
conductivity.
For the Dionex ACRS 500, Dionex recommends the use of Dionex Anion Regenerant
Concentrate (P/Ns 037164, 039601) for the best performance. With the DCR Kit, use
Anion Regenerant Concentrate 75 mL of 2.0 N Sulfuric Acid (P/N 057559) or the 4-
Pak (P/N 057555).
For the Dionex CRS 500, Dionex recommends the use of Dionex Cation Regenerant
Concentrate (P/N 039602) for the best performance. With the DCR Kit, use Cation
Regenerant Concentrate 100 mL of 2.06 M TBAOH (P/N 057561) or the 4-Pak (P/N
057556).
the required purity were used to make the eluent (see Section 3.1, "Chemical Purity
Requirements"). If the eluent concentration is too high, the Dionex CRS 500 will not
be able to suppress it, resulting in high background conductivity. Refer to Tables 3 or
4, "Matching Regenerant Concentration and Flow Rate to Eluent Concentration and
Flow Rate," for the Dionex ACRS 500 or to Tables 5 and 6, "Practical Maximum
Eluent Concentration Suppression Guidelines," for the Dionex CCRS 500 and then
increase the regenerant flow rate or increase the regenerant concentration.
your own, contact the Thermo Scientific Regional Office nearest you (see, Thermo
Scientific Worldwide Offices).
Product Manual for Dionex CRS 500 Suppressor
and remove
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