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ACCQPrep HP125
Section 4 Operation
4-14
· Inadequate priming of the pump may cause the A or
B solvent to flow at lower rates. This may be due to
sticking check valves. Open the front panel and tap
the check valves with a wrench while priming to
assist in bubble passage through the pump.
· Solvent supply fitting may be loose allowing small
amounts of air into system, causing minor flow rate
errors of A or B solvent.
· Strong solvent used for injection (if the repeated
injection is a larger volume).
• Solvent bottle refilled with incorrect solvent.
No peaks on chromatogram –
• No sample injected:
· Sample vial empty.
· Sample probe plugged, injection loop plugged, or
probe or injection pump fitting loose.
· Perform dummy injection and watch injector
pump to determine if fluid is being aspirated.
Disconnect tubing at different points and place
into fluid to determine location of problem.
· If loose fitting, tighten or replace if needed.
· If plugged, replace part or connect to a high
pressure pump to dislodge plug.
• Incorrect wavelength used (assuming no other detectors
than UV/UV-vis).
• Compound doesn't absorb light.
• B Solvent not being delivered. Check solvent level,
connections, check valves, confirm solvent lines in
correct bottles, look for leaks.
• Solvent gradient method too weak to elute sample
• Leak in system is preventing fluid from reaching the
detector.
• UV or UV-Vis detector not functioning (the baseline is
completely flat with no visible noise.
· Liquid could be trapped in the detection gap
due to immiscible solvents. When changing
from normal to reverse phase, flush system
with an intermediate solvent miscible with
both phases such as isopropanol, or flush
system when changing phases in order of
polarity.
· Flow cell detection gap obstructed. Remove
the flow cell from the system and view
through the liquid path. The detection rods
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Table of Contents
Troubleshooting
