Chromatography Forum

Hi

A novice here. What I would like to know is how does one update a calibration for a specific method on a GC/MS. I have not received any training on the machine only a week long crash course from the previous analyst in between our work, so i'm currently in self-training hehe.

So what I have tried so far is running my highest standard and there are peaks missing for some compounds (PAH standards). He says I should find the peaks in the chromatogram and shift them, then re-run. How do I shift the peaks, like set the new retention times and all?

If there is anyone who can help, please Thank you.

Gugu

Hi Gugu

Welcome to the forum.

Surely the one who is telling you to shift the peaks can tell you how to do it ? If not, have you looked at the software manuals, or the on-screen help ?

If you need more training your local Bruker supplier is Kevin Reeves at Chromspec; http://chromspec.co.za/

Peter

Hi Peter

I am not understanding him over the phone and I have met Kevin, we were just looking at another problem I had with the filaments but I will contact him as well, thank you. As for the manual, the previous guy came and said it was around but could not find it, i'll check the system's help as well as you suggest. Thanks a lot.

Gugu

Hi Gugu

The manuals will be on a CD, they might even be already loaded on the instrument computer. Or have a search for Scion on the web - Bruker have dropped their GC products and someone else took them over.

I have the older Varian/Bruker instruments which use different software to what you have.

Peter

What do you mean by shift the peaks?

Hi Loekie

What do you mean by shift the peaks?

By shift peaks I actually meant finding them and their exact retention times, other than the retention times that the system reports which are not where the peaks are situated. Do you get me now?

Hi Gugu

The manuals will be on a CD, they might even be already loaded on the instrument computer. Or have a search for Scion on the web - Bruker have dropped their GC products and someone else took them over.

I have the older Varian/Bruker instruments which use different software to what you have.

Peter

Thank you Peter. Though I have also realized that I might need to change the column or cut it off. The other methods are starting to miss peaks now and that really makes it so impossible to calibrate any other method.

You need to go into the calibration method, use the standard to identify the peaks. You don't shift the peaks , you just update the retention time in the software to identify the peak. Check the window given as often a peak has just slipped out of the identification window.