Definitions

[ulrichem]

We’ve struggled with definitions related to NTA since the beginning of BP4NTA. Jon Sobus recently sent these around to a few folks. Curious if anyone has thoughts, strong reactions, edits, or agreement?

“NTA” is a generic umbrella term that captures all analyses that don’t involve target analytes and standards (i.e., everything listed below).
“De novo NTA” (I’m not a fan of “True NTA” but that’s what I’m referring to here) involves formula and structural identification based on investigation of spectra and first principles analysis.
“Non-target screening” (the preferred term of NORMAN) involves peak picking, formula estimation, and structure searching using local libraries or large databases (this is closest to what I do).
“Suspect screening” is a specific procedure in which acquired MS data are scanned (without peak picking, I think) for the presence of ions present in a user-defined list of true sample suspects (i.e., things which are actually believed to be present in the sample based on prior knowledge or logical expectation – this activity does NOT involve using large generic chemical libraries).

[gpblack]

I really like that there are terms to differentiate between de novo NTA and NTS, but I’ve always heard NTS and felt it was synonymous with NTA. I’m not saying that’s accurate, but maybe others have thought the same?

• This reply was modified 1 year, 6 months ago by gpblack.

[Seth Newton]

I agree with @gpblack that NTS in my mind has always been the European word for NTA. But the way it’s defined here is closer to what I would call Suspect Screening and the definition of Suspect Screening here I would call something like semi-targeted analysis. But all of these activities can go under the umbrella term NTA

[SLN-chem]

I agree with Seth and Gabby! I like having 4 different terms for these definitions (1. umbrella term, 2. spectral/first principles analysis, 3. peak picking first then large database search, 4. peak picking based on a suspect list), but I have not heard NTS vs. NTA used in this way before. Suspect screening I have heard used for definitions 3 and 4.

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