23:00 Mar 9, 2011 

Hi Karina: I was not able to post a discussion... a while ago. Thanks for the selection of my answer. I believe, however, that K. Donnelly's siggestion, as seconded by Drs. Neil and Hartong is the most likely one (I am 99% sure of this). This is a first or second course in organic chemistry. They will use this phrase exactly "MS of organic compounds with different functional groups". This phrase has occurred thousands of times in thousands of textbooks and books. Just for the sake of setting the record straight, also for the sake of you having a correct translation. Introductory organic chemistry students of course will have reaction (including decomposition) rxn products to analyze by MS, but the fact that this phrase comes after other mentions of topics, give it away.. It's what K. Donnelly suggested and what Drs. Neil and Hartong seconded.
Thank you.

01:00 Mar 6, 2011 

I agree with your assessment. I am also happy that we have found the resolution to this particular question...

00:44 Mar 6, 2011 

Hello Dr Darakjian
I did not agree with K Donnelly's answer because it provides 'a way out', but simply because I think it is the best translation.
Apart from that, I am happy that we all seem to agree on the matter, especially for Karina's sake.

23:50 Mar 5, 2011 

If it's a typo, I also agree with you and with K. Donnely's suggested answer. Not because it provides a way out, but because that's what they teach in college organic chemistry courses.

23:44 Mar 5, 2011 

chemical reactions are classified as 1) single displacement, rxns, 2) double displacement rxns, 3) decomposition rxns (4) precpitation rxns and oxidation reduction. There does not have to be more thatn one type of reactant (as in decomposition).

23:39 Mar 5, 2011 

I apologize for the typing mistake. It should have been Dr. Neil.

23:29 Mar 5, 2011 

First of all, I would like to mention that 'decompuesto' does not exist in Spanish: it should be 'descompuesto'.
So, whichever way you look at it, we are dealing with a typo here. I therefore think that K Donnelly's suggestion is the way to go, since it obviates the need to put extra words in the translation that do not appear in the source text. Whereas I don't really agree with Neil that 'decomposition products' is an oxymoron (you could also define a 'product' as 'something produced'), I do think that 'decomposition products' is a pleonasm in the present context: a mass spectrum implies 'decomposition products' by definition.
That being said, I really hope you made some typos in your previous post in the discussion, Zareh, and that you did not say 'Dr Meo' on purpose. Either way, I think an apology is in place.

17:30 Mar 5, 2011 

Decomposition products is a scientific term. Not all reactions are decompositions, therefore, it cannot be an oxymoron, I would say...

14:32 Mar 5, 2011 

I agree with you Ron, the typo is the more obvious answer.
@ Zareh to me 'decomposition products' is a bad term in itself - it's an oxymoron. Personally I would say 'decomposition compounds/constituents/elements' - products surely come from 2 or more reactants combining.....however the expression is there in broad daylight in your references.....

11:08 Mar 5, 2011 

Hello Zareh,
I don't mean to question your knowledge about MS.
My main reason for disagreeing with you is the fact that I find K Donnelly's solution better: all you have to assume is a minor typo in the source text and you get a sentence that makes perfect sense.

21:35 Mar 4, 2011 

Hi Neil,
Same here: I just did Control+F to find the term 'decomposed' in the text. Nevertheless, I really think they are talking about decomposing mass spectra (whichever way they do it) as shown in the example I gave in my original answer and in the 2nd example I gave in my answer to you.
But I don't want to confuse Karina here, so I'll repeat that I think that K Donelly is probably right (and everybody agreeing with him/her).
The only reason I haven't withdrawn my answer yet is that I want to make sure that Karina can see at least K Donnelly's comment. To be honest, I don't know what will happen to the discussion if I withdraw my answer.

21:26 Mar 4, 2011 

I did look at the ref., but I haven't finished reading all 180 pages of it to find the relevant parts.... ;)
But your example is not 'decomposing MS' - "the test set were decomposed"; it's a different meaning...as is "mass spectra decomposed using..." - they refer to how th eMS have been treated not how they have been performed.

21:15 Mar 4, 2011 

This seems to be a course in mass spectroscopy. Students would not do any mathematical decomposition... they would just for for the location and intensities of the peaks, on the x-axis. This would allow them to identify the nature of the ionized fragment. By doing this for a number of fragments, they would know what the structure is.

21:07 Mar 4, 2011 

Neil, if you look at the reference I gave, you will see that it's full of decomposing MS.
Some (really) random sentences:

spectra in the test set (e.g., TS 1-1, TS 1-2, or TS 2) were decomposed into the same number of levels and ...

... mass spectra decomposed using the SWT (A and B respectively).

This doesn't change the fact that I think that K Donnelly (to whom I had addressed my first response, the other ones hadn't arrived to my PC yet) is most probably right.

20:58 Mar 4, 2011 

I fail to see why you would need to mathematically 'decompose' a mass spectrum as they are really rather straightforward to assign.

20:56 Mar 4, 2011 

I feel slightly embarrassed here - I think you are absolutely right (which doesn't change the fact that mass spectra can be decomposed - mathematically, I think).

20:56 Mar 4, 2011 

"Decomposed" is not used in mass spectroscopy. It is not a "decomposition", it is a " fragmentation ", during which bonds
are broken through ionizing radiation, normally.

20:53 Mar 4, 2011 

I think you could be right, a mass spectrum always show various fractions / groups (even decomposition fragments, if you want to call them that) of a molecule - it is the nature of the beast. Therefore it seems redundant to say a 'decomposed mass spectrum' as all mass spectra are of molecules which have been fragmented (decomposed) indicating various functional groups of the original molecule. Sorry if that's not too clear Karina! I think K Donnelly has hit it on the head - a possible typo.
(Anyway - decomposed is not something unstable molecules do in chemistry, maybe in biology but not in chemistry, they may evaporate, crystalise, dissolve, contract, expand......but not decompose

19:39 Mar 4, 2011 

Is it possible this is a typo? I think it should read "Espectros de masa de compuestos con distintos grupos funcionales" (Mass spectra of compounds with different functional groups)