Chromatography Forum

Posted: **Tue Sep 30, 2008 3:06 pm**

Using an Alliance 2790 in conjunction with a Waters LCT Mass spectrometer.

The syringe seems fine, sample is being withdrawn from the vials. Mobile phase is present, and reaching the MS ok. I've bypassed the column completely so it isn't a column issue, and I can't find any leaks. However I get completely flat chromatagrams containing only chemical noise from the MP.

The MS part seems fine, however I'm not seeing any sample peaks. I've checked the needle and the injection port. Both seem unblocked and correct. I'll try the injection valve tomorrow. Any other possibilities?

Thanks for any suggestions.

Posted: **Tue Sep 30, 2008 3:21 pm**

Is that a standard sample that you know will produce certain peaks?

Posted: **Tue Sep 30, 2008 3:38 pm**

Posted: **Wed Oct 01, 2008 12:02 pm**

Have your tried direct infusion in your MS to see if your MS is working OK?

Posted: **Wed Oct 01, 2008 12:45 pm**

Yes, the MS is fine.

Posted: **Thu Oct 02, 2008 2:09 pm**

Fixed.

There was glass - froma broken vial insert? - in the block between the needle port seat, and the needle. Not obvious to see!

Chromatography Forum

Waters Alliance 2790 no peaks?!

Waters Alliance 2790 no peaks?!