What is the fragment loss for 51 peak in the given mass spectrum?

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In summary, the conversation is about analyzing a mass spectrum for a molecule with the molecular formula C9H10O2, and the deduced structure of a Benzene ring with a COOC2H5 substituent. The speaker is working on determining the fragments shown on the mass spec, and has deduced 150, 122, 105, and 77 as the molecular weights for different fragments. However, they are having trouble determining the fragment for a peak at 51 and are seeking assistance.
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Homework Statement



I'm analysing a mass spectrum I've been given for a molecule with the molecular formula of C9H10O2.

The structure iv deduced is a Benzene ring with COOC2H5 substituent.

so its... Benzene-C(=O)-O-C2H5

I'm working out the fragments shown on the mass spec. Those given to me are 150, 122, 105, 77, 51.

So far, I've deduced:
150 - the molecule as it is
122 - the molecule loses C2H2 (ethene) and leaves an alcohol
105 - the molecule loses C2H5O' (an Ethoxy radical)
77 - the molecule loses the whole substituent of C(=O)-O-C2H5 and leaves an Benzene ring

The problem is, i can't work out the 51 peak? What is lost here? Can a benzene ring be broken - to my knowledge it is stable and hence would not fragment?

Please help me on this :)
 
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Read up on http://www.chemistry.ccsu.edu/glagovich/teaching/316/ms/aromatic.html" .
 
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1. What is mass spec fragment loss?

Mass spec fragment loss refers to the loss of smaller fragments from a larger molecule during the process of mass spectrometry. This can occur due to the ionization process or during the fragmentation stage.

2. How does mass spec fragment loss affect the accuracy of results?

The extent of mass spec fragment loss can affect the accuracy of results by changing the molecular weight of the sample and potentially altering the ratio of ions detected. This can lead to incorrect identification or quantification of compounds.

3. What factors can contribute to mass spec fragment loss?

Factors that can contribute to mass spec fragment loss include the type of ionization used, the molecular structure of the sample, and the energy used during the fragmentation stage. Environmental factors such as temperature and pressure can also play a role.

4. How can mass spec fragment loss be minimized?

To minimize mass spec fragment loss, careful selection of ionization methods, fragmentation techniques, and instrument settings can be used. Additionally, sample preparation techniques such as derivatization can help stabilize the molecule and prevent fragmentation.

5. Can mass spec fragment loss be used for structural analysis?

Yes, mass spec fragment loss can be used for structural analysis as the fragments can provide information about the molecular structure of the sample. By analyzing the mass and fragmentation patterns, scientists can determine the connectivity of atoms and functional groups within the molecule.

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