Red Pool P Indicator
Ryan Thomas
In Playboy magazine they reported a story about a chemical indicator which
turns bright red when people pee in your pool. I guess it reacts with uric
acid or something. The article said it was available in Europe, but I haven't
heard of it in the United States.
Are there any chemical experts who know what the chemical composition of such
an indicator might be? I think PH tests would be useless in the environment
of a pool, given the confusing factors of chlorine, sweat, rain, beer, etc.
It seems like it would have to be something which reacts fairly specifically.
---Ryan
Duke McMullan n5gax
(Ryan Thomas) writes:
>In Playboy magazine they reported a story about a chemical indicator which
>turns bright red when people pee in your pool.
>Are there any chemical experts who know what the chemical composition of such
>an indicator might be?
I asked that question last year...I was told it's plain, old, vanilla phenolph-
thalein. (Helluva hyphenation; I couldn't resist it.... ;^)
WHOOOPS! I'm sorry! I shouldn't have written that. I'm NOT a chemical ex-
pert!
d
--
"I purr, therefore I am." -- Rene Decates
Duke McMullan n5gax nss13429r phon505-255-4642 ee53...@hydra.unm.edu
Mike Van Pelt
>In article <31...@exodus.Eng.Sun.COM> wo...@neon-tetra.Eng.Sun.COM (Ryan Thomas) writes:
>I asked that question last year...I was told it's plain, old, vanilla phenolph-
>thalein. (Helluva hyphenation; I couldn't resist it.... ;^)
Not a good idea -- It might work (I think urine is normally alkaline)
but people swimming in the pool might swallow some water, and
phenolpthalein is the active ingredient in Ex-Lax.
--
Mike Van Pelt Headland Technology/Video 7 ...ames!vsi1!v7fs1!mvp
The electronic networks, of course, have always been the terrorist's
most reliable ally, for they have never failed to bend over backwards
to give him what he craves: extravagant publicity. -- Petr Beckmann
Duke McMullan n5gax
using phenolphthalein in swimming pools:
>Not a good idea -- It might work (I think urine is normally alkaline)
>but people swimming in the pool might swallow some water, and
>phenolpthalein is the active ingredient in Ex-Lax.
Mike, that was my reaction last year. The guy who answered the original
query (someone in Scotland; I forget his name) wrote back that nope, the
necessary level for urine alarming is well below the level that causes the
schessendribblens. I've been meaning to put a little phenolphthalein in the
sean just to see if it works, but still haven't gotten around to it.
No one else offered any opinions, but at this very moment it occurs to me that
I could simply wander into a pool supply shop and ask...I'm sure they'd either
tell me, or let me read the package labeling. I gotta do that; I'll post any
profound findings to the group.
Larry Lippman
I have heard the above story from other sources, and based upon
some reasons that are about to follow, I am rather skeptical that such a
"Pool P" indicator actually exists.
Consider the following:
1. Urine contains about 95% water and 2% urea.
2. An average home swimming pool contains say, 5,000 gallons of water.
3. A "healthy piss" :-) is say, 250 mL, and according to (1) above
would yield at most, say, 5 gm of urea.
4. We therefore have, at most, 5 gm of urea in 19,000 kg of water,
for a concentration of less than 0.5 ppm.
5. If we added even 0.5 kg (a *huge* amount) of an "indicator" to
5,000 gallons of water, we would have an indicator concentration
of only 26 ppm.
According to the above, an indicator with a concentration of 26 ppm
in a swimming pool would have to detect with *significant* visibility a
concentration of urea that is well under 0.5 ppm.
AIN'T NO WAY! It would require a decent laboratory double-beam
spectrophotometer to detect such a change - clearly invisible to the human
eye.
I certainly realize that it would take some minutes for the urine
to fully disperse throughout the pool, so the local concentration would be
initially much higher than 0.5 ppm around the swimmer. However, I would
guess than within a few seconds the maximum urea concentration around
the swimmer would still be well below 200 ppm.
The above example is predicated upon adding 0.5 kg of indicator
to a swimming pool. This is a *huge* amount of indicator, which still
results in an ineffective concentration when diluted in 5,000 gallons
of water (26 ppm). As an example, phenolphthalein indicator solution
used for laboratory titrations is 1% (10,000 ppm) to ensure visibility.
Compare 10,000 ppm with 26 ppm...
Furthermore, let's consider if there is *any* chemical indicator
which will turn red in the presence of urine. Let's first examine
phenolphthalein, which turns from colorless to red over a pH of 8.2 to
10.0. Human urine has almost no pH variation beyond the range of 4.5
to 8.0. It would require some serious pathology to result in a high
enough pH to be detected by phenolphthalein - *if* the phenolphthalein
concentration were high enough to be useful as an indicator. In addition,
sodium hypochlorite solution is most commonly used to treat residential
swimming pools, and a pool so treated tends to run alkaline - which in
itself could cause phenolphthalein to turn red.
The above considerations notwithstanding, one is *not* going to
detect urine in a swimming pool by means of pH change.
The only constituent of significance in urine to further consider
is urea. While I do not claim to know the characteristics of every
indicator dye, offhand I know of no such indicator which will turn red
in the presence of urea - let alone in the presence of free chlorine
and in the very dilute indicator concentration found in a swimming pool.
Colorimetric procedures for determination of urea involve multiple
reagents and multiple preparation steps - not very conducive to swimming
pool conditions.
In closing, I would like to state that clinical chemistry
determinations while in a swimming pool is a topic worthy of further
research. In fact, I would even propose a name for such an environment.
Since we already have "in vivo" and "in vitro", how about the phrase
"in natatio" to describe such conditions? :-)
Larry Lippman @ Recognition Research Corp. "Have you hugged your cat today?"
VOICE: 716/688-1231 {boulder, rutgers, watmath}!ub!kitty!larry
FAX: 716/741-9635 {utzoo, uunet}!/ \aerion!larry
Mark H. North
>
> I have heard the above story from other sources, and based upon
>some reasons that are about to follow, I am rather skeptical that such a
>"Pool P" indicator actually exists.
>
>
> AIN'T NO WAY! It would require a decent laboratory double-beam
>spectrophotometer to detect such a change - clearly invisible to the human
>eye.
>
Hey Larry where've you been? Say Larry, didja ever notice when you pee into
a toilet someone has put that there blue stuff in how your pee turns green?
Or do you pee sitting down? Seems to me there might be indicators other
than chemical, perhaps physical. Didja ever think of that?
-- Just a physicist ball busting a chemist 8^).
Mark
Just fun folks. It's a joke. Larry gets it if you don't. Your turn Larry.
Larry Lippman
> > I have heard the above story from other sources, and based upon
> >some reasons that are about to follow, I am rather skeptical that such a
> >"Pool P" indicator actually exists.
> >
> > [ chemical analysis deleted ]
>
> a toilet someone has put that there blue stuff in how your pee turns green?
> Or do you pee sitting down? Seems to me there might be indicators other
> than chemical, perhaps physical. Didja ever think of that?
>
> -- Just a physicist ball busting a chemist 8^).
We don't use toilet bowl treatment cartridges in my house because
we have eight indoor cats. You see, cats being cats, they sometimes use
the toilet bowl as a drinking fountain, and it wouldn't be very kind to
pollute it with chemicals. :-)
Offhand, I can't recall peeing into a toilet bowl with a treatment
cartridge and watching the blue color turn green. But I take your word
for it! It could also mean that your pee is more alkaline than mine,
though.
The toilet bowl comparison is not quite the same as a swimming
pool. I would guess the initial indicator concentration (with a fresh
cartridge) to be between 100 and 500 ppm, which is much higher than in
my hypothetical swimming pool example. Also, I would guess the pee
concentration prior to flushing to be at least 50,000 ppm. In addition,
a toilet bowl would not have interfering chemicals such as chlorine,
and would be closer to neutral pH. Most of the toilet bowl cartridges
are nothing more than some a deodorant, a surfactant (to prevent, uh,
material from "sticking" to the bowl), and a colorant.
So, clearly, a toilet bowl is a *much* more favorable environment
for indicator use than a swimming pool! :-)
Now, I would speculate that an indicator dye made of equal amounts
of neutral red and methylene blue would turn from blue to green with a
transition pH of around 7.0. So, if your urine were slightly alkaline
(a pH as high as 8.0 is normal), it would probably turn green.
What a great idea for a Net Sci.Chem Experiment! Who wants to
try this out and report the results? Better yet would be to instrument
the toilet bowl with a recording pH meter to see exactly how much pH
variation does occur...
Mark, the ball is back in your court!
P.S.: Can you imagine the *ultimate* toilet bowl treatment cartridge
marketing ploy:
"NEW IMPROVED TIDY-BOWL NOW FEATURING Clini-Color [tm]"
"From the miracle of modern chemistry comes a toilet bowl water
treatment system which diagnoses up to 37 diseases every time
you use the toilet. Just compare the color of the water in the
toilet bowl with the enclosed color chart for an instant diagnosis
in the privacy of your bathroom. Buy new, improved TIDY-BOWL
with Clini-Color [tm] - it's like having a doctor in the bowl,
er, house!"
Michael A. Pagels
|> In article <14...@manta.NOSC.MIL>, no...@manta.NOSC.MIL (Mark H. North) writes:
[ lots of stuff deleted ]
|>
|> Offhand, I can't recall peeing into a toilet bowl with a treatment
|> cartridge and watching the blue color turn green. But I take your word
|> for it! It could also mean that your pee is more alkaline than mine,
|> though.
|>
[ lots of stuff deleted ]
Do we really need to invoke chemistry for the color change? How about the simple physical explaination:
blue colored fluid + yellow colored fluid = green colored fluid
Evan G. Bauman
> I have heard the above story from other sources, and based upon
>some reasons that are about to follow, I am rather skeptical that such a
>"Pool P" indicator actually exists.
>
> Consider the following:
>
>1. Urine contains about 95% water and 2% urea.
>
>2. An average home swimming pool contains say, 5,000 gallons of water.
Only if it's a large bathtub. My pool has at least 17000 gallons
and it's not even a diving pool. An average sized back yard
diving pool is about 30,000 gallons of water.
I tend to agree with Larry that you would need an enormous amount of indicator
to change the color of the water. I have to pour large amounts
of material in my pool water to change alkalinity or chlorine levels
just a few ppm.
Evan G. Bauman - Combustion/Reaction Engineering
Shell Development Company - Westhollow Research Center
PO Box 1380; Houston, TX 77251-1380
bau...@shell.com "The owls are not what they seem"
BACS Data Communications Group
>...Most of the toilet bowl cartridges are nothing more than some a
>deodorant, a surfactant (to prevent, uh, material from "sticking" to
>the bowl), and a colorant.
>...P.S.: Can you imagine the *ultimate* toilet bowl treatment
>cartridge marketing ploy:
>"NEW IMPROVED TIDY-BOWL NOW FEATURING Clini-Color [tm]"
>
>"From the miracle of modern chemistry comes a toilet bowl water
>treatment system which diagnoses up to 37 diseases every time
>you use the toilet. Just compare the color of the water in the
>toilet bowl with the enclosed color chart for an instant diagnosis
>in the privacy of your bathroom. Buy new, improved TIDY-BOWL
>with Clini-Color [tm] - it's like having a doctor in the bowl,
>er, house!"
>
>:-)
Will Larry Niven's "Autodoc" be a bathroom fixture?
How about an electronic toilet seat which weighs you before and after,
and (special yuppie appeal) prints a report. It's made of transparent
plastic with internal flashing LEDs...
"Don't be a dumb sh*t -- Get the Smart Seat from Heathkit"
But this is sci._chem_...
Housecleaning freaks buy those toilet-tank gadgets in the belief that
they have some sanitizing action. The fine print reveals that they do
little except turn the water blue. When you encounter that stuff,
proper etiquette is to inform the host(ess) that the Smurfs have been
peeing in his/her toilet. :^)
--
Frank Reid re...@ucs.indiana.edu
Larry Lippman
> |> Offhand, I can't recall peeing into a toilet bowl with a treatment
> |> cartridge and watching the blue color turn green. But I take your word
> |> for it! It could also mean that your pee is more alkaline than mine,
> |> though.
> [ lots of stuff deleted ]
>
> Do we really need to invoke chemistry for the color change? How about the
> simple physical explaination:
>
> blue colored fluid + yellow colored fluid = green colored fluid
While the above is true in the case of subtractive color mixing of
pigments, we are dealing with *transparent* colored fluids in a highly
reflective environment (glazed toilet bowl). Unlike a pigment, light
will pass *through* the fluids, strike the bowl, and be reflected back
out.
Would we not be dealing with additive color mixing, not unlike
that of two colored light sources? Or would it be that of two colored
filters? And what about "background" effects if the toilet bowl were
other than white in color?
Hmmmm... Think about this, is the answer that obvious? Will the
resultant color actually be green? Or will it be clear, black or some
other color?
Not only does the mystery deepen, but we now have a good *physics*
problem for Mark! :-)
Mark H. North
>
> Hmmmm... Think about this, is the answer that obvious? Will the
>resultant color actually be green? Or will it be clear, black or some
>other color?
Somewhere between mauve and charteuse I think.
>
> Not only does the mystery deepen, but we now have a good *physics*
>problem for Mark! :-)
>
Something I can really sink my teeth into, right?
>Larry Lippman @ Recognition Research Corp. "Have you hugged your cat today?"
Anybody that hugs cats can't be all bad. 8^)
Mark
John Stanley
la...@kitty.UUCP (Larry Lippman) writes:
> In article <14...@manta.NOSC.MIL>, no...@manta.NOSC.MIL (Mark H. North) writes
> > Hey Larry where've you been? Say Larry, didja ever notice when you pee into
> > a toilet someone has put that there blue stuff in how your pee turns green?
> Offhand, I can't recall peeing into a toilet bowl with a treatment
> cartridge and watching the blue color turn green. But I take your word
> for it! It could also mean that your pee is more alkaline than mine,
> though.
Let's see, blue water plus yellow water equals green water. Sounds like
a simple case of additive colors. Not much chemistry there.
The final test is to run all this through the old Beckman UV-VIS
spectrometer. Is the final mixture the sum of the two parts?
You may use YOUR spectrometer for this, thank you.
<> "If winning is not important, then why keep score?" -- Turtle Head
<> "Eaten any good books lately?" -- Q
<> "Sanity check!" "Sorry, we can't accept it, it's from out of state." - me
James W. Swonger
The pool supply places around here sell the stuff. It does not claim to
turn the entire pool red. The claim is that it turns the area around the
"perpetrator" red. In this case you are dealing with a much smaller volume.
At the time of the "event" you are talking about a very localized, high
concentration of urea surrounded by a large amount of uncontaminated
(for the moment) water. Therefore the requirements on sensitivity of the
indicator are not as severe as postulated.
Larry Lippman
I would very much like to obtain a sample of this material. If
I am able to procure such a sample, I will conduct some simple laboratory
tests to evaluate sensitivity and efficacy in the presence of a chlorine
environment and report the results to the Net.
I did check with two of the larger pool supply firms in the
Buffalo, NY area (Beauty Pools, Inc. and Frontier Pools & Spas), and
both tell the same story: they have heard of such a product, but they
have never actually seen it either personally or in any distributor
catalogs, and consider it a "rumor" only.
If some Net reader can provide me with the name and address of
a dealer who actually stocks this material, I will make an effort to
order a small quantity.