This Information Applies To: Agilent LC Samplers except dual needle multisamplers
High pressure in the LC sampler is sometimes due to a clog in the needle seat assembly, the needle, or the sample loop. The needle can pick up sample particulates or plugs from the vial caps when the sampler is drawing the sample. When the valve switches back to mainpass, they are forced into the seat capillary and cause an obstruction and high pressure.
Tips: There is a procedure to back flush the needle seat using Lab Advisor (see Backflushing the Needle Seat of the Agilent Vialsampler). If you do not have Lab Advisor available, follow this procedure.
Steps to Follow
Caution: This procedure is not applicable to dual needle samplers
Preparing the system
Backflushing the needle seat
Flushing the Needle and/or Sample Loop Capillary
Restoring the system
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