What is in a potato juice ?

[Externet]

From my grandpa era tricks; when the windshield wipers stopped working, rubbing a split potato onto the glass allowed to see very well until those old vacuum motors/hoses get fixed.

And it works great.

What is in that juice? Some surfactant ? Never tried as defogger for my scuba mask. Would it work ?

[Phi for All]

Oxalic acid, apparently. Removes rust, too.

[Sensei]

True scientist would blend potatoes in blender, get juice, fill distillation flask, perform distillation, and try to gather larger amount of product(s) (for various boiling temperatures, refining).

And observe how they reacts with various other known compounds.

Probably a day of work or so, to figure out their molar masses at least.

Density would be known after the initial or second distillation.

Edited January 31, 2016 by Sensei

[ajb]

I want to say vodka, but that is made from potato juice rather than being a component of potato juice. ;-)

[John Cuthber]

True scientist would blend potatoes in blender, get juice, fill distillation flask, perform distillation, and try to gather larger amount of product(s) (for various boiling temperatures, refining).

And observe how they reacts with various other known compounds.

Probably a day of work or so, to figure out their molar masses at least.

Density would be known after the initial or second distillation.

A true scientist already knows that whatever it is that has an effect on the windscreen, the stuff can't be volatile- or it would evaporate to quickly to do any good.

He might also twig the idea that distilling potato pulp will get you practically pure water (maybe a hint of geosmin and things like that).

 

A really good scientist would start out with a potato and a windscreen...

[Ophiolite]

I want to say vodka,

There is nothing wrong with saying vodka, especially if you are in a bar and the bartender asks what you want. But you are in Warsaw, so you already know this.

[John Cuthber]

There is nothing wrong with saying vodka, especially if you are in a bar and the bartender asks what you want. ...

Unless you actually want something else. In that case a compulsion to say vodka would be a problem.

[Sensei]

A true scientist already knows that whatever it is that has an effect on the windscreen, the stuff can't be volatile- or it would evaporate to quickly to do any good.

 

Until performing experiment, good scientist should not make any assumptions.

 

Did you try smearing potatoes on the windscreen to check how long it works, and measuring time.. ?

I did not. I bet you didn't too.

 

BTW,

I checked what typical winter washer fluid, used on windscreen, is made of..

And it's mixture of methanol (even 30% v/v) and other alcohols.

How about that, in the context of mentioned volatility... ?

 

He might also twig the idea that distilling potato pulp will get you practically pure water (maybe a hint of geosmin and things like that).

Receiving water from experimental distillation is also information for scientist: the most likely whatever is inside has higher boiling point than water.

 

A really good scientist would start out with a potato and a windscreen...

 

I don't see how that would help to determine molecular structure of compound?

 

I am reminding you, OP is interested in identification of compound. Its chemical formula, molar mass, properties, etc.

 

[John Cuthber]

 

Until performing experiment, good scientist should not make any assumptions.

 

Did you try smearing potatoes on the windscreen to check how long it works, and measuring time.. ?

I did not. I bet you didn't too.

 

BTW,

I checked what typical winter washer fluid, used on windscreen, is made of..

And it's mixture of methanol (even 30% v/v) and other alcohols.

How about that, in the context of mentioned volatility... ?

 

Receiving water from experimental distillation is also information for scientist: the most likely whatever is inside has higher boiling point than water.

 

 

I don't see how that would help to determine molecular structure of compound?

 

I am reminding you, OP is interested in identification of compound. Its chemical formula, molar mass, properties, etc.

 

"Did you try smearing potatoes on the windscreen "

No I didn't, but I did say "A really good scientist would start out with a potato and a windscreen..."

Winter wash fluid's major requirement is that it doesn't freeze- hence the alcohols.

However that's not the question raised by the OP

" Never tried as defogger for my scuba mask. Would it work ?"

Now, not many people's scuba masks are below freezing so why bother with the properties of a winter washer fluid?

Is it because you were hoping to make me look bad?

Nice try.

 

"Receiving water from experimental distillation is also information for scientist:"

Well, yes, the fact that potato has a lot of water in it is information. but I rather suspect that it's information already known to most scietists.

 

"I don't see how that would help to determine molecular structure of compound?"

You have missed something; there is only one report that the substance exists.

It could be that modern spuds- perhaps a different strain or whatever- might simply not work.

So you could be making mashed potato for no reason at all.

The first step is to actually check that the effect is repeatable with the potatoes available to you.

It might also be amusing to see if potatoes still work when they are boiled.

if not then we could conjecture that the material responsible is not heat stable.

 

And that would also invalidate your suggested experiment.

 

Seriously, what is the distilled extract of spuds going to tell you in this case?

 

As far as I can see this suggestion of yours;

"True scientist would blend potatoes in blender, get juice, fill distillation flask, perform distillation, and try to gather larger amount of product(s) (for various boiling temperatures, refining)." is pointless- not least because it doesn't actually involve windscreens.

[Ophiolite]

@John and Sensei

 

Alternatively you could begin with a literature search, as Phi did.

[CharonY]

Research instructions unclear; I have now mashed potatoes with caramellized fennel on my windscreen. Is this where I add the potato vodka?

[John Cuthber]

@John and Sensei

 

Alternatively you could begin with a literature search, as Phi did.

Indeed, and you would then find that potatoes do contain a little oxalic acid - which is used (at much higher concentrations) as a cleaning agent.

However, it's not particularly likely that it would work to stop things misting up.

So I'm leaning towards the OP's opinion (perhaps just a guess) that there's some sort of surfactant present.

Research instructions unclear; I have now mashed potatoes with caramellized fennel on my windscreen. Is this where I add the potato vodka?

If it's the oxalic acid that makes a difference (TBH I doubt it but...) you should add spinach or a rocket salad.

[CharonY]

The content of oxalix acid is quite low from what I remember, roughly that of onions and peas. Do they also remove rust? Spinach is about 20 times higher. I think I will add parsley, to be safe.

[iNow]

Potato, onion, spinach, and parsley finished with vodka. This thread morphed into one about latkes in Russia.

[John Cuthber]

Meanwhile, back at the topic; I wonder if sugars and /or saponins are the active ingredient.

[Sensei]

@John and Sensei

 

Alternatively you could begin with a literature search, as Phi did.

 

Imagine you're in XVIII-XIX century, know nothing about chemistry,physics and science what we know now, and trying to find out what is made of some substance..

Searching and finding literature, is based on previously made research.

I am just suggesting that research can be done by yourself.

It's much more entertaining, and brain developing, than just looking up somebody else work and read..

It's like solving puzzle by yourself, versus letting somebody else do it for you..

Edited January 31, 2016 by Sensei

[John Cuthber]

OK, so lets sum up I said

1 check that it actually works

2 Don't assume that the active ingredient is heat stable and volatile.

 

Whereas you assumed that the best thing to do was make mashed potato.

 

What would have been different in the 17th or 18th C?

 

Would you like to revisit these ideas?

"I am just suggesting that research can be done by yourself.

It's much more entertaining, and brain developing, than just looking up somebody else work and read..

It's like solving puzzle by yourself, versus letting somebody else do it for you.."

[CharonY]

Meanwhile, back at the topic; I wonder if sugars and /or saponins are the active ingredient.

Weell it is kind of on topic. If it is oxalic acid spinach and parsely extract would be more efficient by weight than potatoes.

That is something relatively easy to test.

[Externet]

Thanks.

Even if parsley works better, still would prefer the potato to avoid the mask from fogging. Liquifying parsley and eye-drop bottling it... I hope remembering the task next time.

But smearing a potato works. Zero beading. For about 2 hours under the rain.

Typical easy way we divers do is smearing deep throat spit on the glass. Works well too.

 

! Found the potato listed among the 'products' ----> http://dualsportalchemy.com/2013/08/tip-keeping-your-goggles-fog-free/

[Ophiolite]

Searching and finding literature, is based on previously made research.

I am just suggesting that research can be done by yourself.

It's much more entertaining, and brain developing, than just looking up somebody else work and read..

I don't believe I suggested only carrying out a literature search. If that seemed to be implied that was not my intention. My intention was to suggest beginning ones investigation with a literature search. If that was not clear I hope it is now.

[John Cuthber]

The exchange of PMs between me and Sensei about this is, in my opinion, quite amusing.

[Sensei]

The exchange of PMs between me and Sensei about this is, in my opinion, quite amusing.

Personally I do not share your amusement.

I challenged you to at least isolate compound. And you failed.

Your inability to isolate compound is so much amusing? Then I should have laugh first.

Instead you preferred attacking me with copy and pasted text. 10 times in a row, about that "I am wrong" for every my argument. It was in PM, so I ignored it permanently.

Do not you like my methodology? Then show yours. Where is problem? That you don't want to bother wasting weeks or months on research?

Just because of what I want to do first-distillation (and the simplest thing from the all things to do next, taking a few minutes to few hours to check).

I never said at which temperature and pressure, should be done distillation.

You said you would try drying it (but the quickest drying is done by heating substance! To evaporate water).

Drying at room temperature, of larger amount of juice, would take days if not weeks.

Unless you use yet another substances that reacts with water (f.e.desiccants).

(You complained by allegated heat decomposition of compound under higher temperature, now I can tell the same that used desiccants can cause reaction with substance, and have completely different result than expected (dehydration of solution)).

(Yet another method is decreasing pressure with substance, so water boils at lower temperature, and get rid of it)

So there is no reason to not try distill first, if you want to get rid of water. Especially under lower pressure.

You would evaporate water, and check whether substance has lower or higher boiling temperature than water, and check whether substance is decomposing under higher temperatures.

All-in-one set of informations. Quickly and without additional cost for desiccants.

 

Have potato? Use them in the lab. And make photos in the middle of process. And have isolated product. And show on photos how it is used on windscreen after extraction.

 

Your complained that potato specie can matter? Then ask Externet to send you couple kilos examples (which he undoubtedly checked)..

 

ps. In 2015, I was doing 50 distillations per month.. >400 in whole year.

Don't believe? 18-28 February 2015 http://www.scienceforums.net/topic/87953-distillation-results/

 

ps2. My the main question in PM was: how are you going to identify unknown compound in unknown solution (mixture of unknown compounds) using XIX century knowledge (lack of internet and literature, mass spectrometer etc.) to figure out compound chemical formula..

XIX century = inability to use mass spectrometer, etc. modern methods.

You obviously ignored..

Edited February 2, 2016 by Sensei

[John Cuthber]

I told you it was amusing.

For example the reason why this chunk...

"You said you would try drying it (but the quickest drying is done by heating substance! To evaporate water).

Drying at room temperature, of larger amount of juice, would take days if not weeks.
Unless you use yet another substances that reacts with water (f.e.desiccants)."...

is wrong, is called freeze drying.

 

Re "the main question in PM was: how are you going to identify unknown compound in unknown solution (mixture of unknown compounds) using XIX century knowledge "
Nope, if you look really closely you will see that the OP didn't mention "XIX century knowledge"- that's just something you made up.

 

Re.

"ps. In 2015, I was doing 50 distillations per month.. >400 in whole year.

Don't believe? 18-28 February 2015 http://www.sciencefo...lation-results/

"

 

It's not a question of whether I believe you or not is it?

It's an issue of whether or not it matters.

BTW, you might want to look at this

https://en.wikipedia.org/wiki/False_precision

 

I hope Strange won't object to me "pinching" a reference he used in another thread.

https://en.wikipedia.org/wiki/Law_of_holes

Edited February 2, 2016 by John Cuthber

[Externet]

The part in potato juice that draws my attention is; when sliced, the amount of juice deposited smearing glass, has to be about one drop, if that much. and performs.

And the drop of juice is ~78% water. So a 22 % minuscule amount of a drop of remaining chemicals, performs. And who knows what percentage of that 22% of a drop is responsible for the anti-fogging/wetting effect of interest.

 

And oxalic acid not mentioned here :

 

 

 

 

 

 

[John Cuthber]

There isn't a lot of oxalic acid in potatoes:

Estimates vary

http://www.childrensdayton.org/cms/resource_library/nephrology_files/5f5dec8807c77c52/lithiasis__oxalate_and_diet.pdf

 

http://www.wakehealth.edu/Urology/Kidney-Stones/Oxalate-Content-of-Foods.htm

 

 

and it's not particularly likely to act as an anti misting agent.

 

it's not on that diagram because there's just 0.006% to 0.03% or so.