[Maizeyh75]

Hi, i just wondered if anyone could point me in the right direction on how to find the molecular structure of molecules for e.g. 1-Acetoxy-2-Propanol.
I need to get the daughter ions of this & draw each structure after calculating from the graph from off of Headspace analysis. (GC-MS).

Would really appreciate any advise; am v. in need of some 'headspace' myself at the moment..

[Arkcon]

Hi, i just wondered if anyone could point me in the right direction on how to find the molecular structure of molecules for e.g. 1-Acetoxy-2-Propanol.

Its pretty hard to understand what you're asking here.  You want the molecular structure of this molecule?  That is basic organic chemistry, using its name.  There are programs like Chemdarw, which will do it for you.  But this one is pretty easy.  Can you attempt it?

I need to get the daughter ions of this & draw each structure after calculating from the graph from off of Headspace analysis. (GC-MS).

OK, this is more difficult.  You'll have to consider what structures can form, in gas phase, in a charged environment.  Since you know the molecular mass of the fragments, you may be able to piece it together, using the masses of the atoms.

Would really appreciate any advise; am v. in need of some 'headspace' myself at the moment..

Try to show us more of the assignment, and we can offer some hints.

[Maizeyh75]

Thanks so much for your reply. You are a wonderful human being helping me out like this; I appreciate it so much! 
Well; to try to draw C5,H10,03
                  H
                  ]
CH3CO-cH2-C-CH3
      []          [
      O          Oh

I already had this example but honestly am not very understanding of how to go about it.
From the graph its atomic weight is: 118
It breaks down to a peak of 74 therefore 118-74 gives a count of -44.
The atomic weight of the peak at 74 may be: C3. H6.02
I must subtract -44 from off the structure & in turn draw both structures seperately.
I'm not sure exactly from where on the structure to subtract this 44 from?
My basic understanding is quite poor!

[Maizeyh75]

Still really stuck with this problem..also had no luck downloading the chemdraw or chemsketch.

I've googled and searched so much but still can't find the answer.
Would really appreciate some advice on how to go about it!

[Arkcon]

Thanks so much for your reply. You are a wonderful human being helping me out like this; I appreciate it so much! 
Well; to try to draw C5,H10,03
                  H
                  ]
CH3CO-cH2-C-CH3
      []          [
      O          Oh

I already had this example but honestly am not very understanding of how to go about it.
From the graph its atomic weight is: 118

OK, that's a good first step.  We have better drawing tools, and you can post a drawn image as an attachment on this forum, but you can look into that when you need to.

It breaks down to a peak of 74 therefore 118-74 gives a count of -44.
The atomic weight of the peak at 74 may be: C3. H6.02

You math is correct.  But ... what structure can you draw for this 74 AMU daughter?  Is it a fragment -- that is, did your big molecule get chopped into two pieces?  What is the structure of this daughter, and what is left to make the 44 AMU daughter?  And you you have an idea why it fragmented right at the spot that makes the two daughters?

I must subtract -44 from off the structure & in turn draw both structures seperately.
I'm not sure exactly from where on the structure to subtract this 44 from?
My basic understanding is quite poor!

You're not usually just dumped into a question like this, the advanced topic -- why molecules fragment where they do, and what organic ions are stable as charged gasses is complex.  But maybe you're just supposed to sum atomic weights, like you've started to do?

[Maizeyh75]

Hi
Thanks so much for your reply! I found a good place called 'chemspider' to help me out with the chemical structures, however i thought i should just know how to do this at first glance!
Yes, i think my big molecule got chopped into a few different pieces but i think i need to just draw the (-44) as far as i'm aware. I need to re-look at my graph print out & comprehend it better as there are a few peaks which i'm not sure what to do with. For now i'm just taking the biggest peak & working from there.
I am abit 'dumped into this question' to be honest...

 i'm just going by the atomic weights of structures. It broke up due to the mass spectrophotometry whereby the lighter ions passed through first.
 So to get the daughter ion off
C5,H10,03
                  H
                  ]
CH3CO-cH2-C-CH3
      []          [
      O          Oh
I added up the atomic weights off each element to come up with the (-44 ions that were lost)
So that meant the answer was:
                      H
                      [
                      C- CH3
                      ]
                      OH
=-44.
However i'm just not exactly so confident with finding the correct break-away ions for the remainding structures i have to complete! I don't always know where exactly to start adding up the break away part for example the (-44 part in this example).