I remember using this stuff to trace some old obscure storm drainage, and got some on my hands. Every time I blew my nose, it was VERY bright green for several days.
We used to use this in a tank of water to check tires for leaks. The green color made the bubbles show up very nicely, just like the spirit glass on a level.
I worked with fluorescein and related tracers during my years in biochemical research. My lab-mates and research partners always pronounced the last syllable as rhyming with scene.
Yeah I'm pretty sure I pronounced it incorrectly in the video 😅 typically I'd argue its a regional thing because I'm from Alabama, but in this case it's just because I only came across the word while reading and I've somehow never heard the word said out loud
Divers who must work in dark conditions AND may be at risk from delta P can use a squirt bottle with fluorescein (instead of or in addition to milk or cream) to visualize water movement before possibly becoming trapped by it.
Oh yeah it gets EVERYWHERE, stains BAD, and even the most incredibly dilute solutions are highly visible. Even though I filmed this a month ago I still come across the occasional fluorescent speck
@@integral_chemistrymy worst experience with staining was knocking my vacuum filter apparatus over while filtering picric acid. I ended up just putting a rug over the spot after neutralizing it with NaOH. Was tasting that insanely bitter taste for a week after despite not getting any on me that I saw.
@chemistryofquestionablequa6252 yeah dude picric acid is the worst hands down. Out of everything I've ever made on this channel, picric acid is the singular chemical that has permanently stained every organic surface it came in contact with. I've tried every common and uncommon cleaner you could imagine but it seems here to stay 😅
For info, workup: … [After the reaction] the oil bath is allowed to cool to 90°C and a mixture of 100 mL of water and 5 mL of concentrated hydrochloric acid is added to the reaction mixture. The temperature of the oil bath is raised once more until the water boils. The mixture is stirred until the reaction mass disintegrates and the zinc salts [if you had used zinc chloride] have dissolved. The mass is filtered, the residue ground with water in a mortar, filtered and dried at 100 °C. The fluorescein so obtained is purified by dissolving it in sodium hydroxide solution, filtering and acidifying the filtrate causing pure fluorescein to precipitate out.
Someone dyed the fountain at the university with a good bit of this in the disodium salt form. At night. The fountain had illumination by mercury vapor lamps so the effect was glorious. Some thought it was radioactive..well, sort of.
It's much more effective to dissolve the raw product in sodium hydroxide solution and protonate it again with dilute sulfuric acid, because the precipitate is easy to filter off then (by vacuum with paper in the porcelain buchner funnel, not on the glass frit!), and dry it in a vacuum desiccator or on a steam bath. You will get a nice dry and easy to grind red stuff this way instead of a gue. But be careful with it: even tiny residues are extremely staining, so the synthesis may end up in a hard to clean mess. I have early videos about the synthesis of fluorescein (anhydrous zinc chloride works very well as a catalyst) and eosin Y on my channel and recomment to check them out... 😊
I'll definitely check out the eosin Y before I give it a shot myself. Been going into too many projects completely blind lately and messing stuff up (plus I feel shouting-out other creators could help build the community instead of stubbornly trying to figure out everything myself). On that note I tried 7 different methods of making potassium nitrite over the last month, and the final one I tried was your method with the formic acid.. which turned out to be definitely the best method along with toxic lead sponge. And yeah I'm not sure why I didn't try the deprotonation/protonation for this stuff.. literally I did that in the past with phenolphthalein so it should have been obvious lol
Here in Germany the synthesis of fluorescein is one of the first preparations chemistry students do in their OC laboratory internship. 😁 Ask me before a future project whenever you like. I might not always have an answer on every theoretical question then, but what I have got is a ton full of experience to share from decades of practising experimental chemistry.
10 nm - 400 nm if you really want to be accurate. However, fluorescein dye’s peak excitation occurs at 495 nm and peak emission at 520 nm, and it can be excited by cobalt blue down to 400 nm, which is what ophthalmologists use to inspect eyes. And remember most consumer UV light sources contain a lot of visible light above UV. I can easily and boldly excite fluorescein dye using a barely visible filtered 365 nm light source.
Fluorescence strongly depend from the evnoironment and experimental conditions, and aqueous solution and solid state are completely different situation.
I have an idea, Na2(Cu(C3N3O3Cl2)4) Is a copper complex, insoluble in water and Is easily produce by mixing solution ad copper sulphate and sodium dichloroisocynurate (spa chlorine)
Okay that procedure was so much less painful than what we did. I can't remember what exactly it was, but we converted the melt more or less directly into something resembling the consistency of dried chewing gum and scraping it out of the flask was an absolute nightmare. One of the worst syntheses I ever ran. Not to mention you'd find water drops randomly turning green weeks later. At least I didn't break the flask while scraping it out and NOT wearing gloves like one of my lab mates. So that's something I guess.
1:40 Um, that's definitely not technically an 11-step reaction. The reaction mechanism may have a total of 11 reactants, intermediates and products, but technically this remains a 1-step reaction.
I used to make that exact argument when I started this channel, but enough people seemed to agree that every electron transfer step counts as a "step". I'd personally agree with you, my friend who is an organic chem professor says he'd consider it a semantic difference and really depends on whether you are trying to emphasize the reaction itself or the movement/transfer of electrons. Again, I agree but people online seem to enjoy seeing every single mechanical movement from reactants to products, and calling it a "step" in that context is better for the layman although potentially frustrating to organic chemists lol
@@integral_chemistry Definitely frustrating for an organic chemist. I would explain it by naming the reaction and talking about mechanistic steps. The subtle difference would not immediately trigger the reaction: Uhh nope. Because as an organic chemist, an FC-reaction is just one step. I would understand the second step as being when you have activated the acid (e.g. to form an NHS ester) in order to couple it to an amine or to label a protein or peptide in a further (third) step. Btw: It often helps to suspend solids in pentane in an ultrasonic bath and then dry them again to remove any remaining solvent. I would also treat the organic phase after the brine wash during extraction and aqueous work-up with a drying agent such as sodium sulphate. Also helps immensely to get water out of the EtOAc.
@@TheFrog1200 Sorry for some reason UA-cam had blocked me from seeing your comment because it was flagged as "offensive" somehow. I definitely take absolutely no offense to your points, I actually very much appreciate the constructive feedback. Only comments I don't appreciate are pedantic critiques on my pronunciation or stuff like that. In any case I do agree and I think your idea of saying something like "It is a single step reaction, BUT here are the 11 discrete mechanism steps that occur within the one reaction" would probably make everyone happy. And thanks for the tip! One thing I considered in retrospect after making this video was to convert it to its soluble sodium salt and then re-precipitate it with dilute HCl. I did that once when I made phenolphthalein and it resulted in the formation of much larger particles that were actually possible to filter and dry. Regardless, I should buy some pentane. Super useful but weirdly hard to find online.
@@integral_chemistry Strange that that was flagged. Well, I just wanted to give feedback in any case, even if it frustrated me a bit at the time. This is unfortunately a problem I have with chemistry content on the internet or in films. It's always a bit annoying when some things are inaccurate or don't really make sense, whatever. But I understand that not all viewers are organic chemists and therefore have to weigh up between technical accuracy and ease of understanding or even didactic teaching. Nevertheless, good videos and fluorescent substances are still great. I keep forgetting how hard it is to get hold of chemicals while I'm sitting here in the lab and could pull anything between HF and litres of pentane out of the drawer.
@@integral_chemistry *floo-rez-tseen* that's as close as I can get with trying to write the German pronunciation using English-look-alike words. Of course, you have to make sure to use a German rather than an English "r" sound.
@bryce4359 - German chemist Adolf von Baeyer did it first. He produced the first synthetic fluorophore (aka; fluorescein) pigment in 1871. It was called “resorcinphthalein” and was made from phthalic anhydride and resorcinol. If you really want to go back, Bernardino de Sahagú, a 16th-century Franciscan missionary and ethnographer, observed and wrote that Lignum nephriticum, a traditional Aztec diuretic derived from the wood of two tree species, (the narra, Pterocarpus indicus, and the Mexican kidneywood, Eysenhardtia polystachya) “was capable of inferring fascinating opalescent hues to the water it came in contact with”. This fluorescence emission was later attributed to matlaline, the oxidation product of one of the flavonoids found in those species of wood. I love Nile Red, but he most definitely didn’t do it first.
AFAIC being first is nifty and all, but in the larger scheme of things, adding to the pool of knowledge, and giving additional perspectives on a subject are vastly more important. When anyone puts out a video on anything I'm interested in (which is pretty much everything science), even if it's something I've done myself, I hungrily watch it to see what extra bits of insight I can gain from it. Some add more to the greater pool of insights than others, but I am rarely disappointed that I watch them, and greatly appreciate the time and effort that goes into them.
@@imikla For sure! I can only imagine that the names I mentioned above would LOVE to be able to see videos like these if they only had the chance. My comment was in line with yours, making sure we don’t disparage someone from putting in the effort just because it’s been done before by someone else. Everyone deserves to experience the magic, and share it!
I'm no chemist by any means, but could you mix the fluro stuff into a clear paint? Would the paint be dark or would it be fluro? Also would the colour last or would it slowly fade?
Excellent work on both the chemistry and video-making.
Thank you very much! The video editing (and speaking) are the main things that have taken the most work over the last year
I remember using this stuff to trace some old obscure storm drainage, and got some on my hands. Every time I blew my nose, it was VERY bright green for several days.
We used to use this in a tank of water to check tires for leaks. The green color made the bubbles show up very nicely, just like the spirit glass on a level.
Awesome! I appreciate the details and aesthetics!
Always appreciate the feedback! I did want to go more into detail on this one as the formation mechanism was so interesting to me
Such a cool synthesis! It would be really neat to see what other dyes could be made from this too
I worked with fluorescein and related tracers during my years in biochemical research. My lab-mates and research partners always pronounced the last syllable as rhyming with scene.
Yeah I'm pretty sure I pronounced it incorrectly in the video 😅 typically I'd argue its a regional thing because I'm from Alabama, but in this case it's just because I only came across the word while reading and I've somehow never heard the word said out loud
Divers who must work in dark conditions AND may be at risk from delta P can use a squirt bottle with fluorescein (instead of or in addition to milk or cream) to visualize water movement before possibly becoming trapped by it.
Huh now that I didn't know, thanks for the interesting info!
I was working in a rebotteling lab one day i had to transfer 2k of fluoresine in 150g bottle it took me two hours cleaning afterwards what a mess 😅
Oh yeah it gets EVERYWHERE, stains BAD, and even the most incredibly dilute solutions are highly visible. Even though I filmed this a month ago I still come across the occasional fluorescent speck
@@integral_chemistrymy worst experience with staining was knocking my vacuum filter apparatus over while filtering picric acid. I ended up just putting a rug over the spot after neutralizing it with NaOH. Was tasting that insanely bitter taste for a week after despite not getting any on me that I saw.
@chemistryofquestionablequa6252 yeah dude picric acid is the worst hands down. Out of everything I've ever made on this channel, picric acid is the singular chemical that has permanently stained every organic surface it came in contact with. I've tried every common and uncommon cleaner you could imagine but it seems here to stay 😅
I just made this today in my advanced synthesis lab!
Very nice video looks great!
For info, workup:
… [After the reaction] the oil bath is allowed to cool to 90°C and a mixture of 100 mL of water and 5 mL of concentrated hydrochloric acid is added to the reaction mixture. The temperature of the oil bath is raised once more until the water boils. The mixture is stirred until the reaction mass disintegrates and the zinc salts [if you had used zinc chloride] have dissolved. The mass is filtered, the residue ground with water in a mortar, filtered and dried at 100 °C. The fluorescein so obtained is purified by dissolving it in sodium hydroxide solution, filtering and acidifying the filtrate causing pure fluorescein to precipitate out.
I wonder if you can get the fluorescin to lase in a laser cuvette
Hmm I don't see why not. God i wish analytical instruments didn't cost thousands of dollars..
I'm interested in more dye vids and keep doing the good work
Thank you so much! They seem straightforward, it's just weirdly hard to find direct synthesis literature online
Someone dyed the fountain at the university with a good bit of this in the disodium salt form. At night. The fountain had illumination by mercury vapor lamps so the effect was glorious. Some thought it was radioactive..well, sort of.
What a cool video! I use fluorescein-coupled antibodies at work all the time!
I want to know what music you used in this video, especially the first one - it's so peaceful! Also, I noticed you used it on your other videos too.
I'm glad you like it! I get mixed feedback on the music. Song is 2:32am by Wisanga
@@integral_chemistry thanks! ^^
It's much more effective to dissolve the raw product in sodium hydroxide solution and protonate it again with dilute sulfuric acid, because the precipitate is easy to filter off then (by vacuum with paper in the porcelain buchner funnel, not on the glass frit!), and dry it in a vacuum desiccator or on a steam bath. You will get a nice dry and easy to grind red stuff this way instead of a gue. But be careful with it: even tiny residues are extremely staining, so the synthesis may end up in a hard to clean mess.
I have early videos about the synthesis of fluorescein (anhydrous zinc chloride works very well as a catalyst) and eosin Y on my channel and recomment to check them out... 😊
I'll definitely check out the eosin Y before I give it a shot myself. Been going into too many projects completely blind lately and messing stuff up (plus I feel shouting-out other creators could help build the community instead of stubbornly trying to figure out everything myself).
On that note I tried 7 different methods of making potassium nitrite over the last month, and the final one I tried was your method with the formic acid.. which turned out to be definitely the best method along with toxic lead sponge.
And yeah I'm not sure why I didn't try the deprotonation/protonation for this stuff.. literally I did that in the past with phenolphthalein so it should have been obvious lol
Here in Germany the synthesis of fluorescein is one of the first preparations chemistry students do in their OC laboratory internship. 😁
Ask me before a future project whenever you like. I might not always have an answer on every theoretical question then, but what I have got is a ton full of experience to share from decades of practising experimental chemistry.
Would it be much different with uranium added?
How the resorcinol is made
At the risk of pedantry, UV is < ~390 nm.
Lol yeah that's fair. I've always found it an arbitrary line, but for technical applications sake it is important
10 nm - 400 nm if you really want to be accurate. However, fluorescein dye’s peak excitation occurs at 495 nm and peak emission at 520 nm, and it can be excited by cobalt blue down to 400 nm, which is what ophthalmologists use to inspect eyes. And remember most consumer UV light sources contain a lot of visible light above UV. I can easily and boldly excite fluorescein dye using a barely visible filtered 365 nm light source.
Indeed, 495nm is cyan and 460nm is a strong blue colour.
the glow under uv light is absolutely gorgeous right?
One of my absolute favorites! Been looking into derivatives to try and get some new water-soluble fluorescents with some degree of success
The creepy green light.
Great vid thanks so much for showing us 🫡
My absolute pleasure
4:39 I think what makes it so gummy and far from dry is that it contains the sulphuric acid added before.
Super! Thank you very much!
Fluorescence strongly depend from the evnoironment and experimental conditions, and aqueous solution and solid state are completely different situation.
I never even considered solid state fluorescence.. like thin film? I'd like to read more on that if you know any literature
I have an idea, Na2(Cu(C3N3O3Cl2)4) Is a copper complex, insoluble in water and Is easily produce by mixing solution ad copper sulphate and sodium dichloroisocynurate (spa chlorine)
Is this the stuff in glow sticks?
Fluorescin' ?
It's definitely fluorescing 😛
Beautiful footage, BTW.
(FLOOR - ess - een)
This is the rare time I'll use my excuse of growing up in Alabama 🤣
Okay that procedure was so much less painful than what we did. I can't remember what exactly it was, but we converted the melt more or less directly into something resembling the consistency of dried chewing gum and scraping it out of the flask was an absolute nightmare. One of the worst syntheses I ever ran. Not to mention you'd find water drops randomly turning green weeks later.
At least I didn't break the flask while scraping it out and NOT wearing gloves like one of my lab mates. So that's something I guess.
20 years ago I sold this stuff on ebay as glow dye.
1:40 Um, that's definitely not technically an 11-step reaction. The reaction mechanism may have a total of 11 reactants, intermediates and products, but technically this remains a 1-step reaction.
I used to make that exact argument when I started this channel, but enough people seemed to agree that every electron transfer step counts as a "step". I'd personally agree with you, my friend who is an organic chem professor says he'd consider it a semantic difference and really depends on whether you are trying to emphasize the reaction itself or the movement/transfer of electrons. Again, I agree but people online seem to enjoy seeing every single mechanical movement from reactants to products, and calling it a "step" in that context is better for the layman although potentially frustrating to organic chemists lol
@@integral_chemistry Definitely frustrating for an organic chemist. I would explain it by naming the reaction and talking about mechanistic steps. The subtle difference would not immediately trigger the reaction: Uhh nope. Because as an organic chemist, an FC-reaction is just one step. I would understand the second step as being when you have activated the acid (e.g. to form an NHS ester) in order to couple it to an amine or to label a protein or peptide in a further (third) step.
Btw: It often helps to suspend solids in pentane in an ultrasonic bath and then dry them again to remove any remaining solvent. I would also treat the organic phase after the brine wash during extraction and aqueous work-up with a drying agent such as sodium sulphate. Also helps immensely to get water out of the EtOAc.
@@TheFrog1200 Sorry for some reason UA-cam had blocked me from seeing your comment because it was flagged as "offensive" somehow. I definitely take absolutely no offense to your points, I actually very much appreciate the constructive feedback. Only comments I don't appreciate are pedantic critiques on my pronunciation or stuff like that. In any case I do agree and I think your idea of saying something like "It is a single step reaction, BUT here are the 11 discrete mechanism steps that occur within the one reaction" would probably make everyone happy.
And thanks for the tip! One thing I considered in retrospect after making this video was to convert it to its soluble sodium salt and then re-precipitate it with dilute HCl. I did that once when I made phenolphthalein and it resulted in the formation of much larger particles that were actually possible to filter and dry.
Regardless, I should buy some pentane. Super useful but weirdly hard to find online.
@@integral_chemistry Strange that that was flagged. Well, I just wanted to give feedback in any case, even if it frustrated me a bit at the time. This is unfortunately a problem I have with chemistry content on the internet or in films. It's always a bit annoying when some things are inaccurate or don't really make sense, whatever. But I understand that not all viewers are organic chemists and therefore have to weigh up between technical accuracy and ease of understanding or even didactic teaching. Nevertheless, good videos and fluorescent substances are still great.
I keep forgetting how hard it is to get hold of chemicals while I'm sitting here in the lab and could pull anything between HF and litres of pentane out of the drawer.
I use this in my live Science Shows to demonstrate the power of a UV laser from across the room!
Bro put some on a turtle, trust me. This is gonna be awesome, also be prepared to have plenty of 🍕 pizza😂😂😂
Floor-uh-scene, not floor-eh-sin
Yeah 😅 one of those words I've never heard out loud
Floor-A-Seen not floor-essen.
Flur-essen vs flur-a-scene ... 1970s UK vs 2020s USA ... cool.
The fluorescein do be fluoresc-ing though
Very interesting. We'll have to ask the Germans how they say it when they're awake lol
@@integral_chemistry *floo-rez-tseen* that's as close as I can get with trying to write the German pronunciation using English-look-alike words. Of course, you have to make sure to use a German rather than an English "r" sound.
Fluor-eh-scene, not fluor-eh-sin, I just have to be that dude.
This isn't the one to drink. That's vitamin B1 (I think/hope) and also quinine (banned).
Yeah B vitamins are a similar color, and quinine is blue under UV (Which is honestly really cool too)
хера как ярко
Nile red did it first
So did NurdRage, Experimental chem, Vizz Lab, Hegelrast, RG chemistry, Ale, Gate Chemistry, MIT, and a few dozen others.
@bryce4359 - German chemist Adolf von Baeyer did it first. He produced the first synthetic fluorophore (aka; fluorescein) pigment in 1871. It was called “resorcinphthalein” and was made from phthalic anhydride and resorcinol.
If you really want to go back, Bernardino de Sahagú, a 16th-century Franciscan missionary and ethnographer, observed and wrote that Lignum nephriticum, a traditional Aztec diuretic derived from the wood of two tree species, (the narra, Pterocarpus indicus, and the Mexican kidneywood, Eysenhardtia polystachya) “was capable of inferring fascinating opalescent hues to the water it came in contact with”. This fluorescence emission was later attributed to matlaline, the oxidation product of one of the flavonoids found in those species of wood. I love Nile Red, but he most definitely didn’t do it first.
AFAIC being first is nifty and all, but in the larger scheme of things, adding to the pool of knowledge, and giving additional perspectives on a subject are vastly more important. When anyone puts out a video on anything I'm interested in (which is pretty much everything science), even if it's something I've done myself, I hungrily watch it to see what extra bits of insight I can gain from it. Some add more to the greater pool of insights than others, but I am rarely disappointed that I watch them, and greatly appreciate the time and effort that goes into them.
@@imikla For sure! I can only imagine that the names I mentioned above would LOVE to be able to see videos like these if they only had the chance. My comment was in line with yours, making sure we don’t disparage someone from putting in the effort just because it’s been done before by someone else. Everyone deserves to experience the magic, and share it!
I'm no chemist by any means, but could you mix the fluro stuff into a clear paint? Would the paint be dark or would it be fluro? Also would the colour last or would it slowly fade?