Dear Netters,
I have been struggling with our Waters HPLC
for over a month now and would appreciate ANY clues
that might help sort out the problem. If there is any
interest, I will post a summary of responses.
The problem manifests itself as an extremely wavy
baseline which coincides with the pump cycle of pump B
(6000A Series pump with dual piston design). After
changing the pump seals and check valves, the problem
remains. Every indication now seems to point to a bubble in
one of the pump heads; but, try as I may, I have not been
able to get rid of it. I have tried pumping methanol; I
have used the solvent draw-off valve to pressurize the
intake line while the pump is going at 10ml/min; I have
tried tapping the pump head.
Has anybody else encountered this problem?
ANY tips that might be useful in getting the bubble out of
the pump?
Could anything else explain the wavy baseline (e.g. warn out
cams driving the pump heads, or a particle in the pumping
chamber)?
Would any particular cleaning procedure help?
I will be MOST grateful for any assistance.
Sincerely,
John Marcus
_________________________________________________________
John Marcus Marcus at tpp.uq.oz.au (Dr J.Marcus)
Cooperative Research Centre for Tropical Plant Pathology
5th Level John Hines Building
University of Queensland
St. Lucia, QLD 4072
AUSTRALIA
Fax: 61-7-365-4771
Phone: 61-7-365-4764