PL-GPC 220 User Manual
101
Maintenance
7
Autosampler
Autosampler Needle Removal, Cleaning and Replacement
The most common cause of poor, incomplete injection is blockage of the outer
sheath of the A/S needle. Although injection needle design changes have
largely removed this problem, it is still recommended that the needle is
removed occasionally and checked and cleaned.
1
Switch the PL-GPC 220 system off and remove the mains lead from the back
of the unit.
2
Open the oven compartment lid and locate the Autosampler needle
assembly, positioned between the RI block and the Valco valve head
assembly.
3
Using the 1/4 in wrench, undo the Valco nut connected to the top of the
needle assembly. Prevent the needle assembly from rotating with an 11 mm
wrench.
4
Remove the interconnecting capillary tubing and push to one side to ease
access to the needle.
5
Unscrew the two M3 stainless steel socket cap head screws on the side and
rear of the needle assembly.
6
Withdraw the A/S needle assembly vertically clear of the instrument.
7
Using a 1/4 in wrench (hollow open-ended nut spinner if available),
unscrew the needle.
8
Inspect the outer sheath of the needle and remove any traces of septum
blocking the orifice. If the needle is blocked or damaged replace with a new
one.
9
Tighten the needle into the holder and carefully return the needle assembly
in to the guide tube. Be careful not to bend the needle or get it caught up on
the spring.
Tools required
Description
1/4 ” - 5/16 ” wrench
11 mm open-ended wrench
A hollow shaft 1/4 in nut spinner is preferable but not essential to remove and replace the needle
2 mm Allen key wrench
Allen wrench extender handle
