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St. Chibes
Shermanii


Registered: 02/11/10
Posts: 823
Loc: NC
Last seen: 8 years, 11 months
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KOH with stuff floating around in it?
#14106563 - 03/11/11 11:15 PM (12 years, 10 months ago) |
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I recently purchased a vial of 5% KOH (Potassium Hydroxide) from http://www.hoosiermushrooms.com/mushroom-hunting/hunting-accessories/potassium-hydroxide.html and I had a few questions.
Has anyone purchased anything from these guys before? Good or Bad service/products?
About the KOH: I noticed, when I held the vial of KOH up to the light, that there were thin "flakes?" floating around in it. I didn't think chemicals should have "stuff" floating in it. Is this normal? also Does KOH have a smell? Because I tried to smell it and it had no smell at all.
I would like to know if I was sold a bad product.
I was too lazy to mix my own so I bought this premixed vial, but I'm thinking next time I'll be mixing my own.
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   Check out my Original Instrumental Piece: Photinus pyralis
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inski
Cortinariologist



Registered: 02/28/06
Posts: 5,720
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Re: KOH with stuff floating around in it? [Re: St. Chibes]
#14106694 - 03/11/11 11:40 PM (12 years, 10 months ago) |
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It has probably crystalized slightly, you could look at some with your scope to see if you can see any crystals, if this is the case you can give it a good shake and the crystals should dissolve again, check that your lid on your vial has a good seal.
As for it having any odor, the diluted 5% solution probably has no odor, my big bottle of 15% Potassium Hydroxide has a slight saline or salty smell.
You will notice that your slides that are mounted with KOH will have a crystalline residue after a few days whereas slides mounted with Ammonium Hydroxide (NH4OH) will not.
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Alan Rockefeller
Mycologist


Registered: 03/10/07
Posts: 48,276
Last seen: 11 hours, 45 minutes
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Re: KOH with stuff floating around in it? [Re: inski]
#14106754 - 03/11/11 11:52 PM (12 years, 10 months ago) |
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Quote:
flameclown said: its possible that the solution is saturated, but unlikely because 5% seems pretty low
No, a saturated solution of KOH would be very dangerous. Worse on your skin than strong acids.
I don't think he has a saturated solution.
Quote:
inski said: It has probably crystalized slightly, you could look at some with your scope to see if you can see any crystals, if this is the case you can give it a good shake and the crystals should dissolve again, check that your lid on your vial has a good seal.
He would not have KOH crystals in his solution unless it was extremely concentrated. 5% KOH is not even close to crystallizing out.
If your KOH solution is pure it won't have any odor or anything floating in it.
I think the floating things came from the packaging. They should have not put a strong base with that kind of plastic and/or rubber stopper. It also could have dissolved part of the lid.
Either way, it should not be there and the fact that it is there indicates something is wrong.
You could contact them and be like wtf, but unless the solution is cloudy it probably won't affect your mycology at all.
KOH is very cheap anyway, around the price of table salt.
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inski
Cortinariologist



Registered: 02/28/06
Posts: 5,720
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If the water in a KOH solution is allowed to evaporate crystals will form regardless of the concentration of the solution, place a drop of 5% KOH or even 3% KOH on a slide and leave it over night, a crystalline residue will be left behind.
For reference check the notes on Ammonium Hydroxide in Largent's book How to Identify Mushrooms to Genus III: Microscopic Features, page 22.
I agree with you that there may have been a reaction with the KOH and the packaging but it is probably fine to use.
If you are using fresh material the use of KOH is unnecessary, water is fine because the cells don't need to be rehydrated.
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St. Chibes
Shermanii


Registered: 02/11/10
Posts: 823
Loc: NC
Last seen: 8 years, 11 months
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Re: KOH with stuff floating around in it? [Re: inski]
#14106968 - 03/12/11 12:50 AM (12 years, 10 months ago) |
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Thanks for the responses guys!
The solution appears, to me, to be somewhat cloudy but not very.
I shook the vial (not up and down but around) and the "flakes" did not dissolve. They just kept swirling around until they settled back on the bottom.
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   Check out my Original Instrumental Piece: Photinus pyralis
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karode13
Tāne Mahuta



Registered: 05/19/05
Posts: 15,290
Loc: LV-426
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Re: KOH with stuff floating around in it? [Re: St. Chibes]
#14106979 - 03/12/11 12:54 AM (12 years, 10 months ago) |
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I noticed a batch I made up about 3 months ago had small crystals floating in it the other day. Vigourously shaking didn't dissolve the crystals. I just made up a new batch and it's as normal.
I just looked at the rubber they use in the dropper/lid and it has oxidized to a Brown colour. Not sure if this is the cause, probably is.
Quote:
inski said: If the water in a KOH solution is allowed to evaporate crystals will form regardless of the concentration of the solution, place a drop of 5% KOH or even 3% KOH on a slide and leave it over night, a crystalline residue will be left behind.
Indeed. This is what I've experienced also.
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St. Chibes
Shermanii


Registered: 02/11/10
Posts: 823
Loc: NC
Last seen: 8 years, 11 months
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Re: KOH with stuff floating around in it? [Re: karode13]
#14106999 - 03/12/11 01:02 AM (12 years, 10 months ago) |
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I think I'll just mix up some of my own whenever I can.
Thanks again guys!
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   Check out my Original Instrumental Piece: Photinus pyralis
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