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Increasing the concentration of 30% H2O2

  1. May 26, 2016 #1
    Hi, I am in the process of calibrating our GC and one of the products we expect to find in our experiment is H2O2, but we only have 30% H2O2 in the lab. I can test 5% to 25% by dissolving further in water, so I can get some sort of calibration curve, but I'm stuck at 30%, is there a simple way to reduce the water content of the H2O2? I realise that H2O2 in more pure form can be quite dangerous but I cant find it in the
    Illegal/Dangerous chemical activities thread, so I'm assuming its ok to ask this here.

    Is there a safe limit? I am going to be injecting it into a GC, are there any precautions I should take?

    Thanks in advance for any help.
     
  2. jcsd
  3. May 26, 2016 #2

    SteamKing

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    You can find what is called "high-test peroxide" from some vendors, but this stuff is basically rocket fuel and you may not be able to purchase it off the street without authorization.

    Food-grade peroxide goes to 35% concentration. Buying anything with higher concentration could get you put on a TSA watchlist for people sniffing around sensitive chemicals.

    You also shouldn't try to distill a lower concentration peroxide to a higher concentration becuz all the oxygen is a fire hazard and this stuff is dangerous to sensitive tissues, like your eyeballs. People who work with high concentration peroxide should be wearing their HAZMAT suits to prevent exposure.

    https://en.wikipedia.org/wiki/High-test_peroxide
     
  4. May 26, 2016 #3
    Hi, thanks very much for the info! I've read some of the wiki article it seems quite hazardous, think I will forgo trying to make the stuff and discuss with my supervisor about getting some from a supplier. Thanks again.
     
  5. May 26, 2016 #4
    Why don't you dilute your samples to fall within the 30% range? A very simple solution (pun intended) to your problem.
     
  6. May 26, 2016 #5

    Borek

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    OP wants to extend the calibration to concentrations over 30%, and 30% is the starting material. I don't see how dilution applies.
     
  7. May 26, 2016 #6
    He can dilute his unknown samples down to fall with the max 30% H2O2 limit. If his samples are on the order of 60%, a 1:3 dilution puts him right at 15% hydrogen peroxide, right in the middle of the calibration curve.
     
  8. May 26, 2016 #7

    Borek

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    Ah OK, you mean diluting the samples during the analysis, not the ones used for the calibration curve preparation. I misread your post.
     
  9. May 30, 2016 #8

    DrDu

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    I think you can increase the concentration freezing out some of the water.
     
  10. May 30, 2016 #9

    DrDu

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  11. May 30, 2016 #10
    Dilution of the samples is so much easier.
     
  12. May 30, 2016 #11

    DrDu

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    Admittedly!
     
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