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:
- Put the START/STOP toggle switch in the STOP position and turn the POWER on.
- Squirt a few drops of water into the plunger-irrigation ports.
- 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-80 PUMP SHOULD BE FILTERED THROUGH 0.2µm MEMBRANE FILTERS. USE ONLY LC-GRADE SOLVENTS AND TYPE I REAGENT-GRADE WATER. SEE THE SECTION ON MOBILE PHASE PREPARATION.
- Attach a 50-mL disposable syringe to the prime/purge valve and open the valve one turn (don't forget that system pressure must be below 30 PSI before opening the valve). Aspirate until solvent comes through the pump. Leave the syringe attached with the prime/purge valve open.
- Set the FLOW RATE control to 5 mL/min. Then turn the START/STOP switch to START and pump for 5 minutes. During this purge you may alternately draw back and release the syringe plunger to help dislodge air bubbles from the system.
- Stop the pump. Set the FLOW RATE control to 1 mL/min. Close the prime/purge valve.
- If there is no column attached, you may wish to pump solvent through the injection valve to displace any air and old solvent. Simply start the pump again and collect the waste solvent at the outlet of the injection valve.
- To change solvents, repeat steps 3-7 as appropriate.
- If necessary, reset the FLOW RATE control to 1 mL/min or other appropriate setting.