Harvard PHD 22/2000 pump
Posted: Mon Aug 27, 2007 3:37 pm
by CQ_32
Does anyone use Harvard PHD 22/2000 pump for post column derivatization usage? How about the pulse during the flow switching? Can it be eliminated by adding dampener?
Thank you.
Posted: Mon Aug 27, 2007 4:21 pm
by Mark Tracy
Syringe pumps do not need pulse dampers. In fact, pulse dampers require at least 500 psi of back pressure before they do anything at all, and few syringe pumps have both the pressure rating and volume capacity to operate in that range. (That is why the Pickering syringe pump is so costly, it is special-made for that operating region.) For your application, you do not need a long reaction loop, nor high temperatures, so the operating pressure will be very low.
What you will want to do is to have some relay controls to refill the syringe at the beginning of each analysis. Then start the syringe pump, wait for a stable baseline, and start the chromatography.