Fluorescence and Raman Spectroscopy

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  • Опубліковано 13 гру 2024

КОМЕНТАРІ • 10

  • @quimicaparaoitaparaoimeepa3511

    muito bom. obrigado.

  • @qrfarchaeology9391
    @qrfarchaeology9391 Рік тому

    Can Raman Spectroscopy be used for isotopic analysis like Strontium, Argon, or Carbon? I'm new to the chemistry side of analysis of historic and paleo materials but I have research questions that require a variety of lab methods.

    • @Double0pi
      @Double0pi  Рік тому

      I have never heard of anyone using Raman for that, and I'm not sure it's possible (though it's not my specialty, so I could be wrong.) Raman works based on electron density, etc., and that's not going to change much (if at all) based on isotopic differences, which are linked to extra numbers of neutrons.
      Everyone I know who does isotopic analysis uses mass spectroscopy. In general, a regular MS is not precise enough to tell the difference between isotopes with similar masses, so often you'll find people using a tandem MS (MS-MS).

    • @qrfarchaeology9391
      @qrfarchaeology9391 Рік тому

      @@Double0pi thanks. I saw a few papers that discussed RAMAN as a way to help determine if a sample of carbon is in a good enough state to get dating results and may be used for relative dating purposes as a qualitative device within a site but wasn't quite good enough for a stand alone quantitative studies.

    • @Double0pi
      @Double0pi  Рік тому

      @@qrfarchaeology9391 That makes sense. Raman is great at doing qualitative and quantitative studies of hydrocarbons--the sort of compounds that would be used, eventually, to do carbon dating. So if you have an old sample and want to know if it has enough carbon left to do carbon dating, Raman would be a great tool.
      Being a biogeochemist, most of the people I know who use carbon-14 use it to look at carbon uptake (e.g. primary production), and there is plenty of carbon for them to analyze--so they'll use a scintillator to detect decay. I'm not sure that it is possible to do that for considerably older samples, but I am hardly the best person to talk about detection limits for that sort of instrument. I honestly have more friends who do stable isotope work (also the only isotope work I've ever done), where mass spec is the only choice.

    • @qrfarchaeology9391
      @qrfarchaeology9391 Рік тому

      @@Double0pi speaking of MS, I read about ZooMS where otherwise unidentifiable animal remains were fired up and a reading could be made to determine species. With RAMAN being significantly less destructive and being good for qualitative studies, would it be a good choice to use for identifying animal remains?

  • @charlottemilligan8534
    @charlottemilligan8534 4 роки тому

    I take it this is a lecture from an Analytic Chem class. Grad or undergrad?

    • @Double0pi
      @Double0pi  4 роки тому

      Undergrad. We don't have a Master's in Chem here.
      BTW, I'll have all of the Gen Chem 1 videos posted by the end of March, in case you use them with your students!

    • @charlottemilligan8534
      @charlottemilligan8534 4 роки тому

      @@Double0pi Thank you. The HUGE delta between the Analytic Chem I took in 1982 and now is staggering.

    • @Double0pi
      @Double0pi  4 роки тому +1

      @@charlottemilligan8534 YES!!!
      Not sure my students believe me when I tell them that the IR in my undergrad lab had a pen attached to an arm that moved back & forth