Teledyne ACCQPrep HP125 Installation And Operation Manual page 64

ACCQPrep HP125
Section 4 Operation
4-18
a. Remove guard column (if installed) and check
back pressure. If this corrects the problem,
replace the guard column or following the wash-
ing procedure below.
b. Remove preparative column and check back
pressure.
c. If the column is clogged, try flushing with stron-
ger solvent than mobile phase: (this procedure
may damage polymeric reverse phases). A flush
protocol could include: 100% MeOH or ACN
without buffers or modifiers followed by 100%
DCM, followed by 100% hexanes. Reverse the
order of solvents to get back to 100% ACN or
MeOH.
d. Reverse the column connections and flush.
e. Place the column outlet (which was originally
the column inlet) over a beaker so any particle
that are flushed out don't get into the system.
f. Filter samples in the future to prevent problems.
Fractions not correct volume –
• Air trapped in pump head:
· Reprime and test again.
· Collect all with 100%A and 100%B. If only 1 solvent
shows ½ filled fractions, one of the heads is not
priming. Remove the front panel and loosen the
fitting of each individual head while running the
pumps in manual control.
• Air leak in inlet lines:
· Remove front panel and examine inlet lines while
operating. If small air bubbles exist, follow tubing
back to source, examining for source of air bubbles.
Injection valve dripping –
• Valve rotor is damaged due to particulates in the flow
stream or injected sample. Remove the injection valve
stator using a 9/64" hex wrench (the stator is the part
with the tubing connections). The rotor can be lifted out
with a finger nail and replaced (PN: 209009917).
Inspect the face of the stator for scratches. In rare cases
the stator must also be replaced (PN: 209009919).