Proper startup and shutdown procedure is vital for long and dependable pump life. The two most important considerations are:
- NEVER START THE PUMP WITH DRY PLUNGERS
- NEVER LEAVE STAGNANT MOBILE PHASE IN THE PUMP
Correct startup procedure is to purge the pump as follows:
- Turn the POWER on.
- Squirt a few drops of water into the plunger-irrigation ports. Use only enough water to moisten the plungers.
- Place the solvent-uptake frit into a glass reagent bottle containing 40:60 (v:v:) acetonitrile:water. Elevating the reservoir to provide hydrostatic pressure will be helpful.
NOTE: ALL SOLVENTS AND MOBILE PHASES USED IN THE PM-90 PUMP SHOULD BE FILTERED
THROUGH 0.2µm MEMBRANE FILTERS. USE ONLY LC-GRADE SOLVENTS AND TYPE I REAGENT-GRADE WATER.
- Attach the luer adapter (supplied) to a 60 mL disposable syringe. Remove the purge plug from the manifold (don't forget that system pressure must be below 30 PSI before opening the plug) and replace with the luer adapter. Aspirate until solvent comes through the pump. Leave the syringe attached.
- Press the PURGE Key, then press the RUN/STOP key to start the purge. Purge for five minutes. During this purge you may alternately draw back and release the syringe plunger to help dislodge air bubbles from the system.
- Press the RUN/STOP key to stop the pump. Note: The pump may take 1-2 seconds to come to a complete stop following purge. Set the flow to 1000µl/min. Replace the luer adapter with the plug.
- If there is no column attached, you may wish to pump solvent through the injection valve (in the 'inject' position) to displace any air and old solvent. Simply start the pump by pressing the RUN/STOP key and collect the waste solvent at the outlet of the injection valve.
- To change solvents, or to switch to the mobile phase, repeat steps 3-7 as appropriate.
- If necessary, reset the flow to 100µl/min or other appropriate setting.