When

TIP

With conventional use of the Vanquish system as recommended in this manual, regularly flushing the pump is usually sufficient (see Flushing the Pump to Avoid 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)

  • 6 molar (6 M) nitric acid (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 to prevent any chemical reaction between the nitric acid and the solvent in the waste container.

  5. For 1 hour, apply the flow rate of your application and flush the pump with 6 M nitric acid.

  6. Flush the pump with fresh HPLC-grade water until the pH value is neutral.

  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.

  10. Turn off the pump flow and wait until the system pressure is down to zero.

  11. Uninstall the backpressure capillary and reconnect the system as required by your application.

  12. Purge the pump.

  13. Equilibrate the system.