Thermo Scientific thermoscientific Vanquish Pumps C, Operating Manual

Page: 125 / 296

7 • Maintenance and Service
Pumps C, Pumps F ( VC-Pxx, VF-Pxx)
Operating Manual Page 125
7.4.3.2 Flushing with Persistent Contamination Only
When
TIP With conventional use of the Vanquish system as recommended in
this manual, regularly flushing the degassing channels is usually
sufficient (see
Flushing to Avoid Contamination ( } page 124) ).
With persistent contamination, for example, if ghost peaks appear
reproducibly in your blank chromatogram without injecting a sample,
consider a harsher cleaning procedure. Follow the instructions below.
Parts and additional items required
• Backpressure capillary (from Diagnostics tool kit)
• Nitric acid (20%) (HPLC-grade)
• Waste container (for collecting the nitric acid)
• Fresh water (HPLC-grade)
• Fresh acetonitrile (HPLC-grade)
• New solvent reservoirs with fresh solvent
• New frits for solvent line filters
Follow these steps
1. Turn off the pump flow and wait until the system pressure is down
to zero.
2. Install the backpressure capillary on the pump outlet. Guide the free
end of the capillary to the waste container.
3. Replace the frits in the solvent line filters with new frits.
4. Replace the installed waste container with the new waste container.
5. For 1 hour, apply the flow rate of your application and flush the
pump with 20% nitric acid.
6. Flush the pump with fresh HPLC-grade water until the pH value is
neutral or equal to the fresh HPLC-grade water, respectively.
7. Remove the waste container with the nitric acid and re-install the
waste container that was installed previously.
8. For 2 hours, apply the flow rate of your application and flush the
pump with fresh acetonitrile.
9. Connect the new solvent reservoirs, which contain fresh solvent.