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How many times have you gotten poison ivy and not known you had it until the rash appeared? Or been out camping and wondered whether or not you rubbed the poison oak along the side of the trail?
There are already various ways (e.g., Tecnu) of removing urisol (the oil in urisol (the oil in poison
ivy, oak, and sumac), but the key is knowing when you need to wash.
It would be great to have a fabric or fabric coating that changes colors when it comes in contact with urisol ). For example, the laces on your hiking boots might turn blue if they come in contact with urisol, thereby letting you know immediately that you need to wash your hands after retying your boots or that it's likely that you got poison oak on your legs.
You'd probably have to reapply the coating, just like you need to rewaterproof your Goretex jacket. Or maybe people would just use it like bug repellent- rubbing it on all exposed skin areas.
(?) Chemical Detection Paper
http://www.army-tec...ective-clothing.htm
The military have a sort of similar technology. 2/3 of the way down the page: "The paper is attached to patches to the NBC [nuclear/biological/chemical warfare] suit using either an adhesive backing or Velcro like bonding material. The paper is impregnated with dyes sensitive to different types of chemical warfare agent" [pottedstu, Sep 04 2002, last modified Oct 21 2004]
chemistry of poison ivy
http://waynesword.palomar.edu/ww0802.htm
looking at the molecule, it should be easy for an organic chemist to make a color sensitive test, based on those very active double bonds on the sidechain. [pfperry, Sep 05 2002, last modified Oct 21 2004]
Catechol Colorimetric Assay
http://aem.asm.org/...tent/full/70/7/3814
An iron-based catechol assay is about 1/3 of the way down. [sehrgut, Aug 08 2006]
Catechol-Fe(III) Systems (pdf)
http://www.iupac.or...8/pdf/6008x1205.pdf
A paper from the late '80s investigating the catechol-Fe(III) complex. [sehrgut, Aug 08 2006]
Catechol Diazotization (pdf)
http://www.utm.edu/...ments/Diazonium.pdf
Catechols can form azo dyes: highly-coloured! [sehrgut, Aug 08 2006]
(?) Catechol-Fe(III) Reactions
http://www.uni-rege...h/D-Dihydroxy-e.htm
Another catechol-Fe(III) link. [sehrgut, Aug 08 2006]
[link]
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Um...a quick google search revealed that they are different things...perhaps poison ivy isn't native to the UK. |
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I think that this idea has a great deal of merit. This is not
what I
would class as WIBNI. Although topomap can't identify
precise chemicals that may react with urisol, (s)he has
come up with a good idea. Perhaps other 'bakers might be
able to come up with further suggestions. |
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Welcome topomap, enjoy your croissant. |
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Great idea- there was lots of poison ivy where I was camping this weekend. It doesn't seem to affect me, but I know a few people that are extremely allergic to it, and would benefit from any kind of warning that they have come into contact with it. Don't eat this croissant if it turns blue tomorrow... |
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yamahito: we talked about this before, but stinging nettles are nothing like poison ivy. |
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Stinging nettles (for our American viewers) are nettles which sting you when you brush against the edge of the leaf; the rash is like a bug bite: it appears immediately and lasts a day or two, but it is amenable to bug bite creams. |
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Poison ivy (for our British viewers) is one of a number of plants and trees, to which some large fraction - but not all - of the population is allergic. The rash generally does not appear immediately and lasts a week or more; bug bite cream has little effect on it. |
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I and my son do not appear to be allergic to poison ivy (Eastern Seaboard variety, that looks like ivy with a red stem), but my wife is: she once caught it after my son and I went tramping in the woods and she stayed home. |
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Your poor wife - sounds the worst of both worlds, having some freedom and then falling ill. |
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I agree with madradish. A class idea.
Posting ideas is quite like running for office, topomap, & to gain acceptance as "truly an idea for the halfbakery" you might want to resort to low ploys to rustle up extra votes. The cat and custard lobbies are powerful here, for instance. |
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Comes with custard based anti itch cream, just in case? |
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This is an inspired idea. Welcome, [topomap]. |
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I fancy an alarm built into the clothing as well.....something to the tune of , "RUN MAN!! RUN AND BATHE QUICKLY!!" |
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Poison Ivy is horrible - it transmmits easily on the persons skin - say someone rubs an afflicted spot - they just got it on the hand... next thing you know, they look like a bad 50's movie. Attttttaaaaacccckkkk of the Poison Iiiiiiiivyyy |
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This is a good idea; the impregnation of clothing with a chemical indicator. |
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Pardon my ignorance - and I'm not in any way trying to be negative about the idea - but what dictates whether an idea is valid or a WIBNI. I only ask because of the //It would be great// part of the idea and the 'unknowns' of which indicator to use. |
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Thanks. I am acquianted with the help file. |
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However, why isn't this a WIBNI? We don't know what chemical indicator to use. You can say "Wouldn't it be nice if we could detect the presence of poison ivy". |
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Although no exact formulation is given for the proposed indicator chemical, the use and development of dyes for such purpose is a common form of chemical research; it seems likely that someone practiced in the field who set out specifically to develop the suggested indicator could do so. |
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IMHO, the difference between a WIBNI and a valid idea is the expectation of whether the idea could be baked by someone competent in the appropriate discipline. The author of the idea may not know exactly how to bake it, but would know--at least in a rough sense--who could. |
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Croissant for the idea by the way [topomap]. |
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Uroshiol (the proper name for
Toxicodendron resin, rather than urisol)
contains several
closely-related compounds with long
hydrophobic (fat-soluble) "tails". A wax
would probably be the best medium to
"attract" the oils. The wax could be
suffused with a compound which would
react with phenyldiols (also called
catechols, the class of compounds
uroshiol allergens are in). |
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Since the waxy coating would only allow
highly-hydrophobic substances (such as
uroshiol allergens) "in", a positive
phenyldiol reaction would indicate that
something -- most likely uroshiol
allergens -- had contacted the wax. |
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Unfortunately, most colorimetric
catechol assays either produce UV
"colours", require enzymes, or require
aqueous conditions. However, a
diazotization may work, since azo dyes
are usually so brightly-coloured that a
less-than-efficient reaction might work.
(see links) |
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Leads to investigate are Fe(III)
compounds, catechol oxidase/
tyrosinase/polyphenol oxidase (which
form benzoquinone analogues of
catechols), and diazotizations. |
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Hmmm . . . if only I had easy access to a
simple distillation apparatus, I could
extract uroshiol and start playing with
it. Try a paraffin base with varying
concentrations of p-
nitrobenzenediazonium ion and see
how little uroshiol you can get it to
respond to . . . |
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<irrelevant stinging tree spiel>
Oh, Stinging tree has got to be the worst plant on earth. As a north Queenslander who likes bushwalking, it and I go way back. My grandfather tells stories of loggers (-lumberjacks-) who upon receiving a major dose (say, walking through a thicket of the stuff, stinging hands, legs, all exposed skin) would be hospitalised for weeks, and supposedly people have died from it. |
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A friend of my father got a pretty good sting about a decade ago on his arm and leg; the area still itches and reacts with hot and cold water. |
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If you’re crazy enough to try, the berries of the stinging tree are quite delicious. I suggest a biohazard suit. On your slave monkey. |
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</end irrelevant stinging tree spiel> |
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This idea wouldn’t help with stinging tree, but bun for anything that helps with plant related stings. |
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