Question about interpreting NMR graphs

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TwlilightLoz
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My teacher didn't really go through this properly. I even went back to the teacher and still had a vague idea on how to interpret NMR graphs so could someone tell me everything there is to interpret high resolution NMR graphs?

And also, in gas-liquid chromatography, is it basically this long pipe which is coated with a stationary phase (i.e nitrogen gas, hydrgoen gas) and a mobile phase (acid?) and the substance you inject into it continiously dissolves and evaporates between these 2 phases and the time it takes (retention time?) to come out of the pipe can be used to interpret what chemicals there are in the compound. Is that right?
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ChemistryBud
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(Original post by TwlilightLoz)
My teacher didn't really go through this properly. I even went back to the teacher and still had a vague idea on how to interpret NMR graphs so could someone tell me everything there is to interpret high resolution NMR graphs?

And also, in gas-liquid chromatography, is it basically this long pipe which is coated with a stationary phase (i.e nitrogen gas, hydrgoen gas) and a mobile phase (acid?) and the substance you inject into it continiously dissolves and evaporates between these 2 phases and the time it takes (retention time?) to come out of the pipe can be used to interpret what chemicals there are in the compound. Is that right?
Apologies for simply replying with links, but these pages really do give the best descriptions and it would take a long time to write something similar. A few little points, they are generally referred to as NMR spectra (spectrum, singular) rather than NMR graphs. With gas-liquid chromatography you have the right idea. However the mobile phase is always the gas that you are analysing and the stationary phase is generally a liquid (polymer) on a solid support e.g. silica or a porous material.

Whilst retention times are slightly characteristic and can be useful from an analytical perspective, the method is generally used for the separation of compounds rather than identification. As a result, chromatography instruments are usually coupled to mass spectrometers (i.e. once seperated based upon their retention times the individual compounds can be identified using mass spec). The retention time of a compound will depend on a number of experimental factors (flow rate of the mobile phase, the type of stationary phase used). It will also depend on the physical characteristics of the compound (in particular, its boiling point, polairty and solubility). Reference tables do exist for simple compounds and natural products.

Hope this helps.


Describes low-resolution NMR first before moving onto the additional information gained in high-resolution NMR:
http://www.chemguide.co.uk/analysis/nmr/highres.html

http://www.chemguide.co.uk/analysis/...raphy/gas.html
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TwlilightLoz
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can someone also tell me why a ionic solutions (such as Na+ and OH-) dissolve in water but not in a non- polar solvent? (sorry for my wording of solutions and solvents, i dont know hat they are )
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charco
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(Original post by TwlilightLoz)
can someone also tell me why a ionic solutions (such as Na+ and OH-) dissolve in water but not in a non- polar solvent? (sorry for my wording of solutions and solvents, i dont know hat they are )
Maybe it would be a good idea to start a separate thread as this has nothing to do with the thread title ...
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