Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 71,901   Posts: 1,584,467   Online: 937
      
Page 6 of 7 FirstFirst 1234567 LastLast
Results 51 to 60 of 62
  1. #51
    Athiril's Avatar
    Join Date
    Feb 2009
    Location
    Melbourne, Vic, Australia
    Shooter
    Medium Format
    Posts
    2,664
    Images
    28
    Quote Originally Posted by Photo Engineer View Post
    Here is a thought for testing. Either IR (Infra Red) or NMR (Nuclear Magnetic Resonance) will do the trick. If a local school has either unit, a simple 10 minute test on either will reveal the nature (and possible purity including contaminants) of your material. I can't hurt to ask someone.

    There are huge textbooks of spectra out there that will also help.

    PE


    There are open databases of organic spectral data online now. I found even CD-3 and CD-4. You can also now do this with your android phone with an attachment to the camera iirc.

  2. #52
    Nikola Dulgiarov's Avatar
    Join Date
    Jul 2008
    Location
    Sevilevo, Bulgaria
    Shooter
    Multi Format
    Posts
    129
    Catechol goes at $5/100g, so that is no issue. NIR spectroscopy cannot be carried out in a way as simple as using one's phone (there are apps vor visible light spectroscopy, but it's mainly qualitative. I'll contact some friends and see if I can't get is tested in a mass spectrometer.

  3. #53
    Athiril's Avatar
    Join Date
    Feb 2009
    Location
    Melbourne, Vic, Australia
    Shooter
    Medium Format
    Posts
    2,664
    Images
    28

  4. #54
    Nikola Dulgiarov's Avatar
    Join Date
    Jul 2008
    Location
    Sevilevo, Bulgaria
    Shooter
    Multi Format
    Posts
    129
    Well, I'd rather leave the spectro work to the professionals, given that I only have cursory knowledge of analysis, doing anything on my own will be little more than a waste of time.
    Another remark not directly related to glycin synthesis, but generally useful(I think) : It may be possible to regenerate old brown glycin if you dissolve it in an alkaline solution and add ascorbic acid at 1/10 of the weight of the glycin. Boil until solution clears up and its color lightens. Note that this works for me, but your results may vary, so try it on a small (1/8g) amount and see if it works before going for a large batch.

  5. #55
    Photo Engineer's Avatar
    Join Date
    Apr 2005
    Location
    Rochester, NY
    Shooter
    Multi Format
    Posts
    23,544
    Images
    65
    Spectral analysis might be easier than you think.

    Run the spectrum you wish, then look up glycin in a table of spectra. Compare them. If they match, you are ok. If they are similar, it is probably impure glycin, and if they are totally different, you will know you don't have glycin.

    The ascorbic acid method looks interesting to me.

    PE

  6. #56
    Nikola Dulgiarov's Avatar
    Join Date
    Jul 2008
    Location
    Sevilevo, Bulgaria
    Shooter
    Multi Format
    Posts
    129
    Well, in that case I might be doing it with the school's spectrophotometer, it's a standard unit I've seen in most manuals, so I believe I'd be able to test the glycin.
    Ascorbic acid seems to be a very useful reducing agent, in the color chem. section I posted my tests of making a color developer with CD1( I know, I know, but it's the only thing I've got, and time, I have some time on my hands ), and I've substituted hydroxylamine, which I am reluctant to purchase in the kg range, as it is offered here, with 500mg/l ascorbic acid, which seems to retard oxidation enough to make a reasonably stable developer. Anyhow, I digress

  7. #57
    Photo Engineer's Avatar
    Join Date
    Apr 2005
    Location
    Rochester, NY
    Shooter
    Multi Format
    Posts
    23,544
    Images
    65
    Make sure the spectrophotometer is an IR unit and do NOT dissolve the sample in water. None of the items in the beam are made of glass, but rather are made of huge, specially grown and polished NaBr or NaCl crystals. They are phenomenally expensive. Of course there are special cuvettes that are transparent to IR as well.

    There are some new words for you!

    PE

  8. #58
    Nikola Dulgiarov's Avatar
    Join Date
    Jul 2008
    Location
    Sevilevo, Bulgaria
    Shooter
    Multi Format
    Posts
    129
    I do have some quartz cuvettes I used in my dye laser project, I think their transmission values should reach IR. I have seen people growing NaBr crystals for CO2 lasers, and worrying about water leaks from the cooling jackets. Anyhow, I'll check up the unit soon...

  9. #59
    Photo Engineer's Avatar
    Join Date
    Apr 2005
    Location
    Rochester, NY
    Shooter
    Multi Format
    Posts
    23,544
    Images
    65
    If you have any interpretatoin problems, I have one spectrum textbook here, but it is not very inclusive. However, I might be able to recall enough of my course in interpretation to help you out. (no promises-I'm very rusty at this)

    PE

  10. #60
    piu58's Avatar
    Join Date
    May 2006
    Location
    Leipzig, Germany
    Shooter
    Medium Format
    Posts
    605
    > in the range or $10-15 to the gram

    You can get photographyc glycin by a much lower price

    http://www.bhphotovideo.com/c/produc...phenyl_10.html
    ---
    Uwe Pilz

Page 6 of 7 FirstFirst 1234567 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin