use of Phlorogucinol and Lycopodium

[dolphinscales]

Hello one and all trust you are having a most excellent day

I have a query - does any one out there in labbie land use Phlorogucinol and Lycopodium?
If so what for?


cheers for any help

[Robbie]

Hi there!

We use Phloroglucinol as an indicator for the presence of lignin in plants. An alternative to this is Toluidine Blue.

Receipes for these were given earlier this year in a post.

Have not met up with Lycopodium though I seem to remember it being used as a homeopathic treatment.

All the best!

Robbie

[dolphinscales]

Thanks Robbie - thought that Phloroglucinol was an indicator used in Biol but was unsure for what - so cheers for that

[JudyM]

We still use phloroglucinol to stain lignin.

Mix 2.5g phloroglucinol in 100ml of 95% ethanol.
Add conc. HCl until ppt forms.

It can also be used as a reagent for pentosans - 3g in 100ml ethanol.

Lycopodium are the yellow spores from the club mosses.We don't use it anymore.
I think it may have been used with the old Web of Life text 20 odd years ago.

Cheers

[dolphinscales]

Excellent Judy - many thanks

i shall add them to the get rid of list -lol always a good thing

[Louise]

Hi,
Lycopodium is used for observing Brownian Motion under a microscope. Usually placed in a smoke cell.
Louise

[macca]

Hi there!

We use Phloroglucinol as an indicator for the presence of lignin in plants. An alternative to this is Toluidine Blue.

Receipes for these were given earlier this year in a post.

Have not met up with Lycopodium though I seem to remember it being used as a homeopathic treatment.

All the best!

Robbie

Is there another alternative to the toluidine Blue we don't have either of these, thanks

[Lyn]

Lycopodium is regarded as a flammable solid. I still have a small quantity in stock but noone has ever asked for it in all the time I have been here (loooooong time) and I think it may be time to dispose of it forever.

[smiley]

Lycopodium can be used like a type of flash powder. Chuck a teaspoonful into a campfire and it flashes and crackles like a magic trick.

We used to aerate a little pile of it inside a tin with a lit candle (by using a length of aquarium hose), and it would flash and blow the lid off the can.

You can also examine the spores under a microscope, because they're quite big, so we used to use them as a precursor to examining cells under the microscope, by placing a few spores on a minigrid and estimating their size.

And in conclusion may I just say Hooray for Old People since I only know all this because I've been a Lab Tech since forever.

[Merilyn1]

Mmmmm, campfire magic trick, love the idea! Too bad I don't have any (or is that a good thing?)

[J]

Hear, Hear, Smiley !!!

[Lyn]

Maybe I'll just hang on to it for a little longer. Might try it out with the exploding lid off the can demo. I like a little pyrotechnics. Campfire magic hmmmmm. Thanks Smiley.

[Loopy]

We use flour in a tin with a candle to show how a fire in a silo can be explosive....

[Lyn]

The first time I saw the flour in the can experiment the explosion blew the lid off the tin and it just missed the fluorescent light fitting in the chemistry lab. The last time we did it was for Science week and apparently it was a flop. I wasn't there for the demo. So what type of flour should be used? Can cornflour do the trick? How tall should a candle be? Suggestions welcome.

[Loopy]

We place several spoons of plain flour in a petri dish inside the can. Make sure the hose you blow through is resting in the petri dish so you you can easily make a flour cloud inside the tin when you give it a good huff. The height of candle is not so important but I wouldn't make it too tall...Hope this helps..

[Lyn]

Thanks Lou. I don't know what went wrong with the demo. The flour may have had some moisture in it from being kept in the fridge perhaps. Anyhow hopefully the next time it will work. Might try the lycopodium and see if it still has some spark left in it.

[mtg]

I thought Lycopodium powder was used in a Yr 12 surface tension prac too.

[smiley]

Yep - although fine pepper can work too.