Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Chemical makeup of tapwater

  1. Apr 25, 2005 #1

    DaveC426913

    User Avatar
    Gold Member

    I am encountering a phenomenon that I am at a loss to explain. I am finding a distinct odour of garlic in ice cubes and drinking water in my home and at my work. I am wondering what the volatile chemicals in garlic are that might be similar to something in the water.

    It happens in two different cities a hundred miles apart (work and home), which rules out many theories.

    At home, it is occurs in ice cubes made from my ice maker. They have a very distinct garlic smell to them. This is not just me, others can smell it as well. It easily transfers. If I pick the ice up in my hands, even just tossing them into my glass, my hands will reek of garlic - enough for someone else to conclusively identify it as garlic by the smell on my hands alone.

    At my work, I notice it in the filtered water (one of those charcoal filtering systems), though there it is less pronounced.



    I can probably look for common causes or mundane connections myself. I'm curious about the chemical makeup of garlic, and if there might be something in the water that's similar.
     
  2. jcsd
  3. Apr 25, 2005 #2

    Gokul43201

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Dave,

    I'm going to give this thread a day or two here. If nothing much comes of that, I'll move it to Chemistry, where you'll probably get better inputs on your peculiar problem.
     
  4. Apr 25, 2005 #3

    DaveC426913

    User Avatar
    Gold Member

    Thanks, yeah, that would have been better I suppose. Should have thought of it.
     
  5. Apr 25, 2005 #4
    The stinky stuff in garlic is allicin, which is a thiol (goggle it if you want the actual structure). Common chemicals that smell similar and may well be in your water are mercaptans (RSH). These chemicals make your natural gas stink (t-butyl mercaptan), make onions stink (allyl mercaptan), skunks stink (butyl mercaptan), and make asphalt stink (I believe that's a combination of mercaptans). Don't know what the sorse could be in your area, but when we lived in Pittsburg it was a coke plant down stream.
     
  6. Apr 28, 2005 #5

    DaveC426913

    User Avatar
    Gold Member

    Might it also be present in certain types of plastic or metals such as the tubing to the icemaker? It's newly installed.
     
  7. Apr 28, 2005 #6
    Metals could serve to concentrate sulfur containing compounds (e.g. as MSx) and say with heat release H2S (ever smell a bad catalytic converter). I don't know of any plastics that use mercaptans as platicizers. However sulfonamides are used in some plastics. I have never worked with such compounds so I have no clue as to if they stink. Also it is possible that in the production of the plastic various sulfur impurities could produce thiol compounds (ever smell a tire fire ). A simple experiment would be to eliminate the ice maker and use tap water and see if the ice still stinks.
     
  8. Apr 28, 2005 #7

    Astronuc

    User Avatar

    Staff: Mentor

    Could the garlic odor come from other foods in your refrigerator? Plastics absorb odor it seems.

    Also, some well and groundwater may have natural sulfur and sulfur-eating bacteria. We have had to shock our well with chlorine bleach occasionally to get mitigate the bacteria. Are you on a private well (yours) or municipal water distribution system? If on a municipal system, they should be treating with chlorine or ozone, and perhaps fluoride if there is no natural source.

    Otherwise, water is H2O with dissolved minerals and metal cations from the ground and any metal piping that is not properly passivated.
     
  9. May 2, 2005 #8

    Gokul43201

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Moving this to Chemistry...perhaps there may be more help out there.
     
  10. May 2, 2005 #9

    GCT

    User Avatar
    Science Advisor
    Homework Helper

    Well, some insecticides are garlic based, the smell of garlic repels the insects, perhaps some of it is getting into your water system through runoff in a nearby water source and is not being filtered out properly due to its distinctive chemical properties. Not quite sure though.
     
  11. May 2, 2005 #10

    DaveC426913

    User Avatar
    Gold Member

    Hm. Food for thought.

    I'll do more experimenting, thanks.
     
  12. May 2, 2005 #11

    Monique

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    So, the ice cubes smell of garlic but fresh water does not? Sounds to me that the ice are laying in an environment together with other foods and take over the taste. Cooks use it to make truffle eggs: just put the egg necks to a piece of truffle and it will start tasting like it.
     
  13. May 3, 2005 #12
    Hmmmm....arsenic compunds often smell like garlic...
     
  14. May 3, 2005 #13
    If your talking about arsine we wouldn't be seeing him post ;)
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Chemical makeup of tapwater
  1. Chemical nomenclature (Replies: 6)

  2. Chemical equilibrium (Replies: 4)

Loading...