Quattro Micro mass shift and other troubles

[Cotton Hawes]

Dear friends,

I've recently started at my new job and got an old LC/MS/MS system Alliance 2695/Quattro Micro. This is my first experience with Waters hardware, I used AB before.
Quattro Micro seemed to have mass shift in the mass range I plan to use (100-1000).
I have some Waters calibration mixes, they're a bit old (exp.2005 ), but to my mind salt solutions like NaICs wouldn't suffer.
I've introduced NaICs through direct infusion, made record and compared with ref.file, indeed the mass shift is obvious.

What's the way to solve that problem?

[jody_dunstan]

What you need to do is run the calibration wizard from the tune page, there are three types of calibration; static, scanning and scan speed compensation. The wizard will guide you through these. Make sure you load default.cal before you start, tune MS1 with NaI or NaIC run the wizard on MS1 save it and then tune MS2, run the wizard for MS2 and then save it again. You can check the calibrations by going to 'Calibrate from File' and selecting the correct file (STATMS1, SCANMS1 etc etc). This calibration will be applied to all acquisitions from then on.

Hope this helps, if not please come back to me.

[Cotton Hawes]

Hello, Jody!
Thank you for detailed answer.

I've checked the manual several times again and that's what I've done:
I've opened default.cal (so that "No calibration done"), applied "Calibration Wizard", infused NaICs - Q.Micro recorded 6 files (STAT, SCAN, FAST...) and also a fault message appeared ("RMS residuals are too high >0.2").
Then I pressed "Calibrate" ->"From file", and done it sequentially 6 times, using the corresponding files.

Currently I'm away from the instrument, when I come back to it, I will check whether the performance has changed. I will write back here in the thread.

[carras]

If your instrument shows the message "RMS residuals are too high" there is something wrong with your instrument or your calibration. I suggest you try this: go to the calibration wizard and in File select "uncal.cal" and press OK. This will remove any previous calibration. Then in Edit select the calibration file you need ( I use Naics1) and calibrate as you did before.

Hope it helps. Good luck

[Cotton Hawes]

Thanks, Carras and Jody, following your advices I've managed to recalibrate the instrument successfully.

But having solved one problem, I've got a couple of new

1. I've made the compound optimization (with Autotune - developing MRM), everything went OK. But then Autune started giving strange results - it sets Cone Voltage for any compound to 100 V (maximum in the ramp). If I limit ramping to any other value - Autotune gives this value like optimum. Although when I ramp Cone Voltage manually, hte highest intensity is reached at cone voltage far from 100 V (30-45 usually for different compounds). I wonder why Masslynx offers me maximum anytime.

2. The second is even worse. At the end of day the Source Temp readback SUDDENLY began to increase (I set 120 C). I found it on 160 C, then it increased and increased, and I thought I better vent and turn off. By this time the readback showed 520 C (!!!). Is it possible in principle? I checked the probe and source cover, they seemed not very hot (one could touch by hand). So I turned the instrument off and went home completely embarrassed.