Late elution of peaks on Eksigent nano Tempo Classic

Issue Description 

Late elution of peaks can be caused by many factors.  The two most common are that the flow rate is not correct (too low) and should be recalibrated and the second is a change of mobile phase.

 Resolution

1. Flow Calibration
   1. Turn on the instrument
   2. Open the Eksigent software
   3. Click System / Hardware Diagnostics
   4. Click the Flow Calibration tab
   5. Click the Calibrate Flowmeter button.
   6. For a proper Hardware Diagnostics (not merely troubleshooting), the Re-Initialize Transducers and Auto Tune Controllers must be run prior to the calibration.
   7. Follow the onscreen instructions
2. Changing Mobile Phase

It is essential that both the Mobile Phase in the software and the Mobile Phase in the solvent reservoirs match. Otherwise, inaccurate flow rates will result.

Parts required:

250 mL mobile phase A

100 mL mobile phase B

Tools required:

Pump priming tool (part number 801-00003)

1. Turn on the LC
2. Open the Eksigent software
3. Close the stopcock of the mobile phase reservoir and remove the reservior by pulling on the white portion of the stopcock, not the glass reservoir itself!
4. Release the contents of the reservoir into an approved waste container by opening the stopcock, not by pouring out the top of the reservoir
5. Close the stopcock and add about 10 mL of new mobile phase
6. Hold the blue and white cap onto the reservoir and shake gently to rinse the inside of the reservoir
7. Release the liquid as above
8. Close the stopcock and add about 10 mL mobile phase
9. In the Eksigent software, click System/Mobile Phases/More and perform 2 purges on the channel that is being changed
10. Replace the reservoir containing the new mobile phase onto the LC
11. Open the stopcock
12. Using the Pump Priming Tool, remove any air bubbles by gently moving the Tool up and down
13. Perform 5 purges
14. Close the stopcock of the mobile phase reservoir and remove the reservior by pulling on the white portion of the stopcock, not the glass reservoir itself!
15. Release the contents of the reservoir into an approved waste container by opening the stopcock, not by pouring out the top of the reservoir
16. Close the stopcock and add about 10 mL of new mobile phase
17. Hold the blue and white cap onto the reservoir and shake gently to rinse the inside of the reservoir
18. Release the liquid as above
19. Close the stopcock and add about 40 mL new mobile phase
20. In the Eksigent software, click System/Mobile Phases/More and perform 2 purges on the channel that is being changed
21. Replace the reservoir containing the new mobile phase onto the LC
22. Open the stopcock
23. Using the Pump Priming Tool, remove any air bubbles by gently moving the Tool up and down
24. Perform 5 purges
25. In the Mobile Phases window, enter in the new mobile phase composition to each channel
26. Click Apply and OK to verify that you want to change mobile phase
27. Do not Flush at this time. There is a better way to Flush
28. Close the Mobile Phases window
29. In the Main Window of the Eksigent software, double-click on any bar-graph in the top right corner. A window asking for a password will appear
30. Enter the password (techno) and click OK
31. Click the Other or Pumps tab (it depends on which software version is being used) and locate the Pump Power section
32. Enter 33% if changing channel 1 mobile phases, or 99% for channel 2
33. Click Manuel Override and let run for 15-20 minutes
34. Click the Stop All Flow button and close the Service Menu
35. Calibrate