Chromatography Forum

Hello,

I reciently adquired an API 2000 LC/MS/MS, and I'm founding the following probles:

When I try to made an autotune with PPG standard (without dilution) y see that the signal is about ten times less as in the specifications indicates.

The signal is not stable, when I made infusion of PPG the signal in the TIC window increase in the time. When I stop the adquisition and then press start, the signal don't begin at the last value in the other run, this begin in the same initial value, and then increase.

When infuse standards (pesticidas), I only obtain the Na adduct, the +H adduct, is not present. And of course the signal increase and the sensitivity is low.


I hope, someone can help me!!!!

Best regards

It sounds like you are accumulating spectra. Make sure if the specifications are for one spectrum or accumulation of a number of them...

About the standard infusion, it will depend on your molecules, most of them will give the molecular ion, some of them will give both some of them will give only the Na adduct.

Make sure that your water quality is adequate and that you add some acid in your sample (for positive ion mode). Also in chromatography you will have less problems of Na adducts...

Thank you for your aswer,

I'm sure that i'm not acumulating spectrum (the MCA box is un-matched),

And the water and MeOH is for LC/MS.

I bought a new CEM to solve the low sensitivity, i'll tell you when install it if I can solve the problem

best regards