Chromatography Forum

Hi everybody

This is a Dionex Ultimate 3000 Autosampler which does not hit the center of the vials. Usually not a problem, but this week I had the needle pierce the septum so close to the edge that it scratched off a bit of the teflon seal and get clogged. Also when returning to the injection port I think it does not hit the central point but the needle gets sort of "bent" into the hole. This can't be good for the needle seat. I already looked in the manual but I did not find a way how to calibrate the positions. Any hints from the experienced people around here?
Thank you,
Jörg

At this point in time a Dionex/Thermo rep are the only ones who have an alignment tool the X and Y axis. You can only control the Z axis. If the needle has tried to punture a cap it needs replacement. The only fix we have found to keep the X and Y axies aligned is to make sure you rotate the carosule via the display or instrument panel and never by hand.

We had this very problem on two of our Ultimate systems within 6 months of purchase and have not had it since (~1 yr) since we started using the menu to rotate the tray. The only time it is acceptable to move the tray by hand is when the power is off to the auto sampler (by power off I mean the master switch on the back of the instrument, the front button puts it in standby which still supplies power to the motor).

Hope that helps.