Metabolomics Society Forum

Hello,
I want to ask how I can find the internal standard using MS-DIAL.
I try to construct both .msp and .txt files about the Precursor m/z and the information which was necessary for identification.
But I can find the metabolite (internal standard) in my data.

Thanks for any suggestion

Good question. I'd like to know the answer as well.

Anyone more experienced would help us?

Hello guys.

In this book chapter we explained how to do that: https://link.springer.com/chapter/10.1007/978-1-0716-2107-3_6#DOI

Basically here is what you need to do:

Create a table with the following information to find the internal standards in data efficiently: Name, m/z (MZ), retention time (RT), Adduct, InChiKey, Formula, Smiles, and Ontology. An example for PC 15:0_18:1(d7) is showed below. Save the table as .txt. Go to Advanced in the “Identification” tab, and select this .txt file. Set 100 min to “Retention time tolerance”, 0.01 Da as “Accurate mass tolerance”, and 80% to “Identification score cut off”.
Name PC 15:0_18:1(d7)
RT 12.75
MZ 775.59531
Adduct [M+Na]+
InChiKey ZEWLMKXMNQOCOQ-GCHPQBSENA-N
Formula C41H73D7NO8P
Smiles [C@](COP(=O)(

• )OCC[N+](C)(C)C)([H])(OC(CCCCCCC/C=C\CCCCCC([2H])([2H])C([2H])([2H])C([2H])([2H])[2H])=O)COC(CCCCCCCCCCCCCC)=O

Ontology PC 


I hope it helps you!