We have had our annual maintenance done on our preparative HPLC system and are still having this issue. Somewhere between the inlet and outlet lines for our 1364E fraction collector bubbles are entering the system. There are no visible bubbles entering the fraction collector in the "IN" line, but there are many in the "OUT" line, the bubbles can also be seen in the fraction collector arm tubing.
We recently had brand new tubing rated for 40-100ml/min burst at only 25ml/min. This may have been faulty tubing but we want to rule out the "leak" issue. Has anyone else had this problem?