Chromatography Forum

Hi.
I`m currently working in some pesticides residue analysis with Waters Acquity Class H UPLC with Xevo TQD Mass Spectrometry.
I set up the system today and run some samples to plot the curve, but when i looked at the chromatogram i realised there was a huge noise until 6,50 minutes when it dissapeared. Anyone knows what its heppening here?

Water Chromatogram:


Spiked Sample:

Hi,

Most likely, the divert valve is set to waste after 6.7min.

It's not possible to comment if your noise is significant because we don't know anything about the method. What is the problem exactly?

And you were right my friend. It was only the divert valve.
Now just need to clean up the system. Guess i injected too much, now that damn peak its showing up everywhere.