Chromatography Forum

Has anyone seen issues with proper sample aliquot taken using the waters method?
We are unable to pull consistent volume from the vial on the autosampler to the sparge.
We have already;
-changed sparge
-changed needle
-changed and clipped transfer line
-passed leak check
-verified proper flow

I'm running out of ideas other than to get rid of my tekmar systems and buy another brand.

EST

Does it pull a bubble at the top of the syringe when trying to pull sample? If so it could be you are pulling a vacuum on the vial because it is not allowing air in, or pressurizing with gas, whichever method it used for pressure equilibration, or the multiport valve is not swithing or is clogged.

You say that it passes leak check. Do you also mean that it passed the benchmark test under the tools section?

Best regards,
Roger Bardsley
Applications Chemist
Teledyne Tekmar

Yes this passes the benchmark.
We have since changed the vent valve so the fluctuations in flow seems to be resolved. We also were seeing system stoppage issues and had an extra main board so we switched that and the system has run great for a month straight so far.