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consult spectra analyze of SSNMR

Question asked by Nikke Yue on Dec 8, 2016

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Dear members of ACS

 

At first , I introduce myself ,my name is Nikke Yue , Hong Kong people and I apologize to ACS for my presumptuous email  to giving disturb

cause I found an unknown fossil, its cling on a sea rock's gap, looks like some kinds of resin, and I done some simply testing it shows

some special , so I consulting to University of Hong Kong, Department of earth & sciences, after testing the physical data given as below:

 

 

  • sink in sea water
  • no effect on acetone
  • gas bubbles observed
  • non-electrostatic
  • flammable: without the odour of amber
  • luster: sub-resinous
  • density: 1.23 g/cm3
  • hardness: <3 (can be scratched by calcite)
  • fracture: appearance conchoidal
  • fluorescence reaction under UV light

 

 

  • University of HK suggested using GC-MS for identification, but their faculty without this instrumentation, and they try to help me
  • contact some commercial lab such like Intertek , when they check up the physical data, the reply are unable to handle itSo I sends the sample to Taiwan National Cheng Kung University , they used ( Solid State Nuclear Magnetic Resonance )to identify my sample, and got the spectra as above attachment

    They told me that after comparative the spectra, and speculated some substance  like polystyrene in the specimenbut  not 100% surely that, in fact as they said geologist are not an expertise of organic chemistry.and I forward the SSNMR spectra to University of HK , they has confirmed that spectra shows are the polystyrene

    So I want consulting to ACS Professor based on SSNMR spectra, it can definitive determinationthe sample are the polystyrene = common plastic?
    Due to polystyrene some features are not match above mentioned physical data, and they both without reasonable explainfor the some unknown ,I through internet search scientific online consulting to one of Taiwan Professor, he is an expert of polystyrene after analyze the above NMR spectra & physical data, Professor replied let me confusing  as below:

     

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  • Dear Mr Yue:( It takes a long period of time to coat such a thick polymer on rocks. Therefore, trying to use fresh polystyrene to coat on the rock, like the pictures you show me, is not reasonable.Sure, you can check physical data of polystyrene in the literature, specially C 13 NMR, and will know the substance on the rock is not polystyrene.Based on your data and a strong peak around 130 ppm on C13 NMR spectrum, the material should be related to polyaromatic compounds  (structure with many benzene rings stick together). Polystyrene can not stick to rocks as tight as pictures shown. Furthermore, fluorescence also suggests the material should be highly conjugated.The rock coated with a thick layer of complicated materials. These materials may contains both organic and inorganic substances. If you want to know the composition of the material, you need to find an analytical laboratory. They will extract the material, analyze it with sophisticated instruments (mass spectroscopy, Nuclear Magnetic Resonance Spectroscopy, Infra-Red... and so on). It is much more complicated than you original thought. In my point of view, people in earth science departments or analytical people may be interested in this type of research. I am a synthetic organic chemistry. In our lab, we trying to make new compounds and not analyze the existed materials.)

     


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    For my limited chemical knowledge I can't handle how to analyze the spectra, as I know scientific detection could be toughand I knew ACS members has fully knowledge of NMR & chemistry, if yours don't mind please kindly provide me somehelpful & best method to go on exploring,  and clarify the above spectra shows are the polystyrene or not, because three of different  University Professor has an inconsistence analyze result, hopefully ACS members can assistance me find out the truth.Thanks!   for yours help I appreciate from the bottom of my heart!   awaiting for your reply!

  • Best Regards

  • Nikke Yue

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