Talk:Mass chromatogram

Fragmentation

This article contains some very serious errors. Just to mention one: fragmentation does not necessarily need to occurr in gas phase. --Kehrli 06:05, 3 August 2006 (UTC)

I'm sorry I do not get your point? You think there are non-gas phase SRM experiments?? How in the world would you do that??? Of course there is non-gas phase fragmentation however in this case the sentence is specificying gas phase fragmentation. Please be specific in your other disputes with this article. I will address each one carefully and diligently.--Nick Y. 17:29, 3 August 2006 (UTC)

Any kind of fragemtation works, not just the one you mentioned. --Kehrli 20:53, 7 August 2006 (UTC)

Huh??? So specifically gas phase fragmentation will not work with an SRM experiment??? An SRM experiment specifically involves gas phase fragmentation. Again how else would one achieve this?? Again I am trying my best to assume good faith but your answer seems mistaken at best and stalling for time at worst. Please explain yourself in detail.--Nick Y. 18:20, 8 August 2006 (UTC)

Nick, you definition implies that only gas fragmentation may be used. But in fact every fragmentation mechanism may be used. Your definition is too restrictive. (Different from what you claim, gas fragmetation is not just mentioned as an example.) Please change this or show a reference that shows that only gas fragemtation may be used. --Kehrli 07:06, 11 August 2006 (UTC)

Aha I think I understand. You think I am speaking about "gas fragmentation" when I am speaking about "gas phase fragmentation" meaning that the ions are in the gas phase when fragmented. There is no such thing as gas fragmentation however you must be thinking of collision induced dissociation. I agree that collision induced dissociation is not the only gas phase fragmentation that can be used; however BIRD, ECD, EDD, IRMPD, SID etc. are all "gas phase fragmentation" methods in that the fragementation event takes place in the gas phase as opposed to teh liquid or solid phases. Perhaps it would be best for you to open a discussion like this with a question such as "I'm not certain if gas dissociation is the only dissociation possible, aren't there other techniques like IRMPD??" Before placing a disputed tag. By the way collision induced dissociation is by far the most common fragmentation method used in SRM.--Nick Y. 16:34, 11 August 2006 (UTC)

WikiProject class rating

This article was automatically assessed because at least one WikiProject had rated the article as stub, and the rating on other projects was brought up to Stub class. BetacommandBot 09:59, 10 November 2007 (UTC)

MRM

I believe we should

1) mention MRM
2) mention that it should not be used any more due to the ambiguity involved

I thus added the text about MRM being deprecated again and supported it with a link from a peer-reviewed journal. I hope that suffices the need for citing sources. Greetings --hroest 09:24, 20 April 2010 (UTC)

Unfortunately, Cham Mead cites a draft of a document I co-authored that is still under review by Pure and Applied Chemistry and not (yet) recognized by IUPAC. In my more recent glossary in Journal of Chromatography A, I included the term with the rationale given in the introduction. In the interest of NPOV, I'll let you reword the article as you see fit, but please take note of the above. --Kkmurray (talk) 19:34, 20 April 2010 (UTC)

Hmm I honestly assumed that when Cham Mead cite it then it would already be a published document and I also assumed that you were unaware of that fact. Obviously you are much better informed on the subject then I am. Well, there is no hurry here. I opt for either deleting my statement again or just commenting it out until it becomes true. Whay do you think? Greetings --hroest 22:39, 20 April 2010 (UTC)

Posting the draft document has caused confusion, but that was an IUPAC decision. I suggest either no mention of MRM or mention with note of potential problems with the term. To throw more fat on the fire, Sparkman considers mass chromatogram itself to be an incorrect term (Sparkman, O. David (2000). Mass spectrometry desk reference. Pittsburgh: Global View Pub. p. 6. ISBN 0-9660813-2-3.). --Kkmurray (talk) 13:47, 21 April 2010 (UTC)

TIC

Here we go again. What are we to do? There are many, many sources, mostly from people who actually do mass spectrometry, who are publishing about it, in multiple reliable places, who define TIC as "total ion chromatogram". And there is IUPAC, who have decided to "deprecate" this and replace it with TICC, the total ion current chromatogram, and reserve TIC for the total ion current. Do we pander to the single source that claims to be the ultimate definition of everything, and use a term that no one else uses? Or do we reflect what everyone else is actually doing? Elemimele (talk) 16:26, 12 February 2026 (UTC)

(incidentally, but this is irrelevant to the current discussion because we must reflect sources, not logic: sooner or later IUPAC will have to change their mind because there is no such thing as an ion current in many modern mass specs. This whole concept was built on the idea of a continuous stream of ions, being converted into a genuine electrical current by some sort of detector device. In an FT device there isn't a current, there is a waveform, and yet we still talk about a TIC in an Orbitrap. You can argue that the TIC in an Orbitrap is a reconstruction of a genuine current of ions that's flowing into the instrument, but since the orbitrap is measuring ions over a particular mass range, while the ions flowing into the instrument may come from a much broader mass range, the actual "total current" that the TIC purports to reflect doesn't exist anywhere in the instrument. In this instance, IUPAC have got themselves in a corner where their definition is meaningless and no one is using it, but as they're an authority, we're still obliged to take note of what they say) Elemimele (talk) 16:39, 12 February 2026 (UTC)