Rinsing The Degassing Channels - Thermo Scientific Dionex UltiMate 3000 Series Operating Instructions Manual

UltiMate 3000 Series:
SRD-3x00 Solvent Racks

7.2 Rinsing the Degassing Channels

To avoid contamination of the degasser, you should prepare fresh solvents, clean the
solvent supply lines, and rinse the degassing channels at regular intervals.
Rinsing the degassing channels is especially important for the channel that degasses aqueous
solvents (for reverse-phase chromatography).
Usually, it is sufficient to rinse all channels with organic solvent. Use a fresh bottle. When
you use water and acetonitrile or methanol, it is usually sufficient to rinse the degassing
channels once per week.
However, adapt the rinsing intervals to the solvents in use. In persistent cases, for example,
reproducible ghost peaks in the chromatogram, follow these steps:
1. Install a backpressure capillary on the pump outlet. The capillary should be
appropriate for generating a backpressure of 20 to 30 MPa.
2. Rinse the degassing channels for 1 hour with 20% nitric acid at the flow rate normally
used for your application.
3. Rinse the degassing channels with fresh HPLC grade water (MS grade if the SRD is
operated together with an NCS-3500RS or NCP-3200RS) until the pH value is neutral.
4. Rinse the degassing channels for two hours with fresh HPLC grade acetonitrile (MS
grade, respectively) at the flow rate normally used for your application.
5. Prepare fresh solvents for your application (using new bottles) and connect them to the
degassing channels.
6. Install new filter frits in the solvent supply line filters.
7. Uninstall the backpressure capillary and reconnect the system as required by your
application.
8. Equilibrate the system.
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