waters alliance carryover

[scio2]

Hi there, I am having serious problems with active carryover when I run my method on a waters alliance system. I have tried altering solvents, needle wash, everything, but as soon as I inject the sample onto the system the carryover is back, and I cannot diminish it.


I dont have the same problem with Agilent

I have read that Waters systems can have this problem, but I dont know why
Can anyone help

Thanks

Scio

[Uwe Neue]

There is the possibility that this is due to adsorption to the seal material. Waters is offerering different seal materials to solve such problems.

[scio2]

thanks Neue, I will look into this
Scio

[Chromatographer2010]

Also make sure your needle wash is actually working. You should get liquid spitting out of the yellow line when you are priming your needle wash.

Also the seal wash frits can become contaminated. Try replacing them. There are two, one on the bottom and one on the top of the injector seal pack.