Triazole metabolites - T, TA, TAA

[Pepter]

Hello all. Does any one have some experience with triazole metabolites ? Iam trying to do some samples based on method
described in this publication no luck as far. Except low sensitivity i have big problems with interfering peaks even after such long clean-up path.
http://ir4.rutgers.edu/Other/Analytical ... epa-01.pdf

I also dont understand why they fortify all samples (include controls) with internal standard before the
SPE column cleaning than they write that "The internal standards are designed to correct for instrumental
variation of signal suppression and not extraction efficiency in this case". - page 1494 left top corner.

[rb6banjo]

I'm with you. That is a very odd statement to make in the context of the procedure they wrote.

Having never run this method myself, I don't really know what to expect as far as interferences go. Sorry, can't help you there.

[Don Shelly]

What is your matrix?

[Pepter]

Hi Don.
Wine right now. Next are apples (i just run few samples and they look much better - no interfering peaks).

Unlucky we working on Agilent LC-MS/MS.
http://www.absciex.com/Documents/Events ... Aiello.pdf

p.s.
sorry for my english

[Don Shelly]

Pepter,

Try this application note with your wine and let me know how it works. We may be able to use it for fruits too. http://www.unitedchem.com/sitefiles/app ... y_GCMS.pdf

Send me an email if you have trouble downloading and I will send you the pdf.

Don

[Pepter]

Thank you Don we will check it after apple extraction.
I have one more question.
How should the standarisation (calibration) look correctly in this method ?

Calibration:
1) Add both standards deutered and "normal" before column cleanup procedure after the extraction ?
2) Add both standards deutered and "normal" into vial after the column cleanup procedure ?
3) Add deutered standard before the cleanup and "normal" into vial ?
4) Add both standards deutered and "normal" before extraction ?

Fortification
1) Add both standards deutered and "normal" before extraction