A large butyl glove w/ the thumb & middle finger cut, will keep your hi-vac trap's Dewar dry. Feed the lines to the trap through the holes. Pull palm/wrist over Dewar. It will also stay cold for a whole weekend. Acetone/ Dry-Ice w/ a ~4" diameter Dewar
The aluminium block is basically a way to turn your hotplate into a block heater. You can also buy block heaters as such (e.g. Eppendorf Thermomixer C). We use them a lot in biochemistry and they do the mixing by shaking the tubes. However, I think few of these offer temperatures above 100C… Maybe one nice extra is that these typically have a timer built in…
Thanks TC for the Video, I have a lifehack that I used too when I worked in the chem Lab in the past My first chemistry lab teacher showed me a trick for gavity filtration. She always had a paperclip in the pocket of her labcoat and when she had to filter somethnig using a funnel, she opend it up and hooked the paperclip on the rim of a flask and attached the funnel afterwards. She did it that the air can escape while filtrating making the filtration faster and prevent overflowing.
Would be interested in the NMR tube cleaning, our SOP is to put 70% nitiric in (50 or more tubes at a time), let sit for 2-3 days whilst GHS labelled in a FC and then washed out with distilled water and acetone 3x each before 15 minutes oven dry before use.
another cool thing about heat blocks is that if you have your own machining equipment (or know someone who does) you can make custom ones built specifically to your needs, plus you could make it from copper to get better thermal conductivity.
NMR tube cleaner: cut two little grooves into the end of the PTFE tube. I will prevent sealing of the path for liquid flow and generate very high local flow velocity. Furthermore, this helps in mechanical support of the cleaning by just turning the NMR tube.
I kind of enjoyed cleaning nmr tubes using the glass apparatus that you can by from Aldrich or wherever. I used to wait until I had about 30-40 and did them all on a Friday afternoon, but in the last company that I worked at all of the nmr instruments (6 of them) had those automated conveyer belt systems where you put your sample into the slot and eventually the nmr gets to your sample to run, then we never retrieved the tube and let the nmr guy take care of removing them, so those days of cleaning tubes were gone.
We actually use the bead bath reservoirs you mentioned at 4:45 in my lab. They're great for drying final products. Just stick an RBF in there with a torion on top- nitrogen in, vacuum out, product dries really quick. Also makes it easy to confirm dryness via LOD.
I need to save this for next year when I do my research lmao. These videos are so good as most of my lecturers cant spend as much time going into detail for lab hacks. TY bro
Great video! About the NMR tube cleaner: As an undergrad I was in a lab that had a NMR tube cleaner made from glass. It worked the same way as your diy cleaner but it was just one piece of equipment you could easily store somewhere. Though I don’t know if this was handmade by our glass blowing team or if it was bought.
Another easy way to get an NMR tube cleaner in a similar fashion. If you have the rubber adapters for the flask (the open conical things so a frit can sit on the flask), you can shove the adapter over a 24/40 septum, poke a hole through the septum with a needle, push a 1 mL plastic pipet tip through the hole and feed the teflon tubing through that. Remove the pipet tip and voila, tubing through a septum that will function similarly to the video's NMR tube cleaner.
I use structural aluminum tubing from McMaster-Carr (1658T13) for all my ring stands and as the lattice for a Schlenck line. It is more rigid and lighter than the solid stuff and the horrible fiberglass rods. It can also be cut with a good tubing cutter. A little more expensive than solid but the advantages offset the cost. As a bonus a the cannula and needles for the Schlenck line fit neatly in the opening of a vertical tube on the lattice.
In addition to the 14/20 septum trick, for 20mL vials we use 24/40 septa: the outer part fits with the screw threads and the inner part fits snug around a 14/20 male joint
I use the armor beads in my biolab in the water bath, they are a little messy because a few always seem to escape, but it did fix the problem of water bath always fouling up and shorting out.
I might opt for a little piece of heatshrink tubing at the top of that temperature probe instead of the electrical tape; less mess, some types come with a glue layer that'll prevent ingress of material at that end, and it provides a bit of strain relief to keep the wires from breaking there. Not really any slower provided that you've got a heat source nearby, as well.
Very interesting video! An alternative to Armor Beads/heating oil that I've used is a sand bath. Something I was wondering, how do you usually carry out light sensitive reactions? The sort that must be done in the dark, rather than under certain wavelenght
I saw the armor beads tip, absolutely agree! My university swapped over to using copper BBs in metal dishes from silicone oil in evaporating dishes in recent years to avoid all the messy cleanup (the BBs may have been cheaper than armor beads, haven't looked their price up myself recently lol)
I am used to oil when doing reflux/distillations. Pretty much for little inconvenience (one paper towel to wipe the RBF afterwards), you get superior heat transfer, and it is very significant difference in comparison with beads/block. Because you can stir the oil inside the bowl. You cannot stir metal beads. Heat transfer isn´t the best, also the same apply for aluminium heating blocks. But it is pretty, nice to work with, and clean - for regular reactions, when heat flux to the RBF does not matter that much, superior :)
@@jakuborvos1575 I usually have to use two paper towels at least for ~100 mL flasks to get the oil completely off, and 3+ towels and one soaked in hexanes to get it off 250 mL flasks. I've also had oil spill in the fume hood so many times that I just seriously dread cleaning up oil ever again.
You can clean NMR tubes by combining a Soxlet apparatus and one of the described setups in one device. By that, hot solvent is rinsed through the tube multiple times automatically. If there is interest, I can dig out the patent number (already expired) with a picture.
@@That_Chemist Please show it in a video. I do not know this one. The method with boiling solvent has the advantage, that the solvent is almost at the boiling point, where its dissolving power is usually the best. And it runs basically forever, as it recycles the solvent. In some cases, I left the tube in there for an hour, which led to many flushing cycles.
We've used copper plated steel bb pellets for high temperature baths before. Their smaller size makes for more contact area. Crazy cheap and readily available at least in the US. I think we got ours from the sporting department in Walmart.
I use a piece of 7 or 8mm glasstube that I drew a bit longer and sealed at the end (under flame of course). As it is similar in size that thermometers, it fits standard thermometer adapters. Insert a wire thermocouple to the end and it works a treat. (some sealant perhaps to make it not fall out by itself). A glass pipette with sealed and should work pretty similarly if you have them in suitable size and lenght. Similar to your septum idea but this works with any standard adapter which I find very convenient.
One lifehack that I used to circumvent having to make capillary tubes was to use a blunt needle instead for spotting TLC plates. To reuse you just wash them in some solvent.
We use 1-5μL capillary pipettes (Hirschmann Ringcaps). They're ideal for TLC spotting and you can get a pack of 250 for 30 bucks, which is just over 10ct per capillary. If you reuse capillaries, a pack of these can easily last you a year or two.
PEG-3000 makes a good substitute for oil in an oil bath--solid at room temperature, no mess, easy to clean. Melts at 60C and usable up to at least 250C.
I‘ve seen metal baths before. It was a bunch of low melting metals (really nasty and toxic stuff too I believe), solid at ambient temperature, got liquid at about 250 and boy could you heat them up. The silicon oil doesn’t handle temps above 300 C well but the metal didn’t have any problems. For what you would need temps up to 500 C in a normal organic chemistry lab though is beyond me
I wonder what the thermal transfer difference between a bath of armor beads (or copper bbs) would be compared to a sand bath since sand baths take a while to heat up and hot plates usually say not to use sand baths since they are somewhat insulating
either way sand baths are my go to for now, until I get a heating mantle (or rather should I say buying the heating mantle element and mounting it into a crock pot shell because its cheaper and looks funny)
@@EdwardTriesToScience I think sand baths would be a good order of magnitude poorer at conducting heat, but if it works then hey. Sand is super safe if you break a flask too, really can't beat it for some stuff.
I like cleaning NMR tubes using pipe cleaners. Mostly because I worked in a polymer lab and gels don't like to be removed with a solvent rinse, but also because it's the intended use of a pipe cleaner (as opposed to arts and crafts).
@@That_Chemist I had a friend that would solvent clean NMR tubes and just put them on an argon line to dry. Granted he was in medchem but it was suuuuper convenient
For the amour beads, I use a cheap aluminum pot from the grocery store. Works just as good as one from Armour bath itself that a lab in my building has.
Need aluminum heating blocks? Visit the university's machine shop and mill it to whatever shape you want. You can make fairly specialized ones for a few bucks in aluminum. Swap metal treating chemicals or demos of anodizing for the machine time. They really enjoyed the demo of colorful anodizing of titanium. ❤
I like the aluminum heating blocks so much. Several companies sell them now for all sizes of vials/tubes/flasks, so I never want to go back to using oil baths. I think it is also cheaper long term because you probably never have to replace them. One thing that could also be nice if your lab has enough money is a "Findenser", no more running water or a recirculating cooler needed for reflux reactions, but they are expensive.
It would take a very long time for me to trust doing reflux with one of these. My first thought is that the "cooling air" would actually be the hot air rising from the hotplate and reaction flask...
We use a Findenser from Heidolph. It's awesome! Can't break easily, can't roll off the bench, can be clamped easily, and also has an additional coolant reflux layer inside in a secondary containment. They're great for medium-boiling solvents, I *think* anything below 40°C is tough but eehhh
TH-cam: hey wanna learn useful information for working in a laboratory? Me, someone with only very basic knowledge on chemistry and absolutely zero desire or plans to start studying for a career in the lab: why yes thank you that sounds handy!
Have enough aluminium foil and glass fibre insulation material for a high temperature distillation or reaction so it won't take multiple days Check the quality of the vacuum and have a backup pump Be gentle to any pH measuring probes
I've used the septum trick but I was never super happy with it. There's always some condensing solvent pooling up where the needle sticks out and if it's something like DCM the septum will not last very long. Plus it gets all over your gloves when you pull of the vial. I've had more success with a big hole in the septum to allow backflow of the solvent.
Usually if you pull vacuum long enough, and of the gathered solvent will evaporate - even if the solvent causes it to swell, it will unswell once it evaporates
There's a much simpler way of making a more resilient and reliable NMR tube cleaner: Get a big Buchner flask and find the largest rubber septum you can fit into the neck. Then find a needle longer than any of the NMR tubes you need to clean, and poke this up through the septum from below before fitting the septum to the flask. Alternatively you can use a broken off section of old stainless steel cannula - works in the same way. Then when you want to clean the NMR tube, invert it and feed it over the needle, so the tip goes right to the end of the tube, and the mouth of the tube is below the rim of the septum. Apply a half-decent vacuum to the flask (house vacuum or a water aspirator is fine for this), and then squirt whatever solvent you want to use for washing the tube into the top of the septum. Works in more or less the same way as those fancy and expensive glass syphon NMR tube cleaners, but since there are no delicate thin bits of glass involved, it won't break so easily. The vacuum draws the liquid up the entire length of the NMR tube, then down the needle and into the flask. The sequence we used in the lab I worked in was: Acetone first, then a bit of dilute hydrochloric acid, then deionized water, finishing with more acetone to chase the water out. Once the flask is full, just remove the septum and pour the contents down the sink. Or if your lab doesn't allow you to pour acetone down the sink, substitute IMS or IPA instead, since these are usually more acceptable to go into wastewater, at least as I understand it.
How have I been living without a metal pellet bath?!? Right now buying some aluminium balls, I might try mixing in some finer pellets to optimise the packing density and hopefully get that thermal transfer even higher. Wish I could afford copper balls...
I have really struggled to find any - if you do find a vendor, and successfully receive some of the correct ones, please share it in the discord! There are similar-sized bumpy red 19/22 ones that you can get from aldrich which also work!
If you wrap the thermocouple end to aluminium foil, you are practically reflecting IR from the probe... That is the reason why we wrap columns and flasks with Al foil during distillations - to insulate them. If you aim for superior acuracy and lowest possible heat capacity of the probe (quick equilibration of reading), invest in Pt/PtRh thermocouples or Pt100 probes (with suitable digital reader). You can put them bare/uncovered inside, and there is little to none ordinary chemicals/compounds that could etch them. Also, classic K probes or J probes for thermocouples are similar chemical resistance than stainless steel, so they are perfectly suitable for distillations of wide array of compounds. Avoid any HCL or acids from them and they would serve you lifetime.
How hot can I heat using such beads? I want to do a vacuum destillation of a silane at 160 °C. Would d~3mm copper grains from EBay be suitable for this?
In the labs I have been at we usually had 3D-Printed adapters for Vials to either 29/24 or whatever the small one commonly used is 14/20 maybe? (both of them Female of course). That way we could connect them to the Schlenk Line and the Rotovap. Of course, Schlenk line is a "Welp, didn't pay attention for a minute and into the base bath my line goes..."-hazard...
What kind of metal would be best for a bead bath? The armor beads are stupid expensive, if the metal holds cold well too this could be better than using ice!
I also regularly did dry ice armour beads, but I often did it with acetone as well - as soon as the dry ice melts, the whole thing sinks which isn’t ideal - this is the one reason why acetone/dry ice is superior
its kinda funny that the most expensive part of the diy digital thermometer is probably the NMR tube itself. the TM-902C is like $5-$20 depending on where you get it (and usually they throw in a couple thermocouples in for free) but NMR tubes are like exorbitantly overpriced ranging from like $5 a tube to like $20-$30 a tube.
The beads are meh. They make a mess. Also aluminum is more reactive than you think. It doesn't like acid or base. Ask me how I know! Use a water bath for anything
Oh and zip-ties. Get a non-sharp edge by twisting off w/ pliers. Grab it right at the locking piece & twist, until it comes off. Do not pull! They won't scratch you anymore.
Poor chemists life hack: cleaning capillary tubes by dumping them in a large beaker containing your favorite cleaning solution (please no piranha), putting it in a dessicator and pulling a strong vacuum for a couple minutes. Let go of vacuum and the solution goes inside the tubes, veeery useful for sealed capillary tubes that go like water in class-labs
@@That_Chemist gotcha, hard to judge size. I tend to use 19/22 septa on 24/40 bump trap on rotovap for vials. The septa eppendorf combo is nice, I've incorporated that after seeing the vid. Cheers
K-type thermocouple is inherently somewhat inaccurate to +- 1-2 degrees. I'd recommend to try pt 100 or pt 1000 thermometers. Yes, they are a bit more expensive but you can rely on the reading to be accurate within 0.01 degrees plus the responsiveness is incredible.
@@That_Chemist I like to monitor the temp when doing solvent distillation so I can be sure that the azeotrope with water has boiled over for example. I like this extra information regarding the purity of my distillate. Also with higherish temperatures (say 150 - 200 C) the platinum RTD greatly outperforms even good mercury thermometers so in some cases can be +-1 C vs +- 0.01 C due to responsiveness and general accuracy of the measurement. I find this extra informative especially when doing quick distillations or small volume distillation.
Guys... you need to clean your NMR tubes???? Hahahaha... What I do in the lab, normally I empty out the sample from the tubes, put 30 to 40 dirty NMR tubes in a galss tube of cooling trap, fill it with acetone and put it in ultrasonic bath for 30 minutes. A glass tube of cooling trap has big diameter, tall enough to immerse the dirty NMR tubes, and can be hanged on ultrasonic bath with help of a clamp. Anyone does like this out there?
Good hacks! For #5, you can simplify the setup by just using an upturned septum directly on the filter flask. See for example: 10.1021/acs.jchemed.1c00337
What makes it even better is that you can jam as many "threads" of Teflon Tube in there as you can manage, so you can clean 1, 2, 5, 10 nmr Tubes at the same time.
@@Bloviator0 Holy **** I didn't even know something like that was possible. Would've saved me from cleaning all those NMR Tubs during my last internship. Oh well...
We used aluminium beads in a cut-off 1L ether can as a heating dish. Do remove the residual label.
That is a good idea actually - those ether bottled just get recycled otherwise, and I always felt like it was a waste
@@That_Chemist Plus you get a handy wide mouth funnel from each. We put mesh in them and used them to catch draining vac pump oil.
A large butyl glove w/ the thumb & middle finger cut, will keep your hi-vac trap's Dewar dry. Feed the lines to the trap through the holes. Pull palm/wrist over Dewar. It will also stay cold for a whole weekend. Acetone/ Dry-Ice w/ a ~4" diameter Dewar
The aluminium block is basically a way to turn your hotplate into a block heater. You can also buy block heaters as such (e.g. Eppendorf Thermomixer C). We use them a lot in biochemistry and they do the mixing by shaking the tubes. However, I think few of these offer temperatures above 100C… Maybe one nice extra is that these typically have a timer built in…
It‘s probably best since you can’t put on any condensers and heating stuff usually results in built up pressure.
Thanks TC for the Video, I have a lifehack that I used too when I worked in the chem Lab in the past
My first chemistry lab teacher showed me a trick for gavity filtration.
She always had a paperclip in the pocket of her labcoat and when she had to filter somethnig using a funnel, she opend it up and hooked the paperclip on the rim of a flask and attached the funnel afterwards. She did it that the air can escape while filtrating making the filtration faster and prevent overflowing.
Would be interested in the NMR tube cleaning, our SOP is to put 70% nitiric in (50 or more tubes at a time), let sit for 2-3 days whilst GHS labelled in a FC and then washed out with distilled water and acetone 3x each before 15 minutes oven dry before use.
another cool thing about heat blocks is that if you have your own machining equipment (or know someone who does) you can make custom ones built specifically to your needs, plus you could make it from copper to get better thermal conductivity.
Good idea!
NMR tube cleaner: cut two little grooves into the end of the PTFE tube. I will prevent sealing of the path for liquid flow and generate very high local flow velocity. Furthermore, this helps in mechanical support of the cleaning by just turning the NMR tube.
I kind of enjoyed cleaning nmr tubes using the glass apparatus that you can by from Aldrich or wherever. I used to wait until I had about 30-40 and did them all on a Friday afternoon, but in the last company that I worked at all of the nmr instruments (6 of them) had those automated conveyer belt systems where you put your sample into the slot and eventually the nmr gets to your sample to run, then we never retrieved the tube and let the nmr guy take care of removing them, so those days of cleaning tubes were gone.
We actually use the bead bath reservoirs you mentioned at 4:45 in my lab. They're great for drying final products. Just stick an RBF in there with a torion on top- nitrogen in, vacuum out, product dries really quick. Also makes it easy to confirm dryness via LOD.
I need to save this for next year when I do my research lmao. These videos are so good as most of my lecturers cant spend as much time going into detail for lab hacks. TY bro
Great video!
About the NMR tube cleaner: As an undergrad I was in a lab that had a NMR tube cleaner made from glass. It worked the same way as your diy cleaner but it was just one piece of equipment you could easily store somewhere. Though I don’t know if this was handmade by our glass blowing team or if it was bought.
They were probably bought - I agree that the glass ones are superior (and hideable)
Another easy way to get an NMR tube cleaner in a similar fashion. If you have the rubber adapters for the flask (the open conical things so a frit can sit on the flask), you can shove the adapter over a 24/40 septum, poke a hole through the septum with a needle, push a 1 mL plastic pipet tip through the hole and feed the teflon tubing through that. Remove the pipet tip and voila, tubing through a septum that will function similarly to the video's NMR tube cleaner.
I use structural aluminum tubing from McMaster-Carr (1658T13) for all my ring stands and as the lattice for a Schlenck line. It is more rigid and lighter than the solid stuff and the horrible fiberglass rods. It can also be cut with a good tubing cutter. A little more expensive than solid but the advantages offset the cost. As a bonus a the cannula and needles for the Schlenck line fit neatly in the opening of a vertical tube on the lattice.
Awesome
In addition to the 14/20 septum trick, for 20mL vials we use 24/40 septa: the outer part fits with the screw threads and the inner part fits snug around a 14/20 male joint
Yes. Please do the desiccator NMR tube cleaner method video.
I use the armor beads in my biolab in the water bath, they are a little messy because a few always seem to escape, but it did fix the problem of water bath always fouling up and shorting out.
Our lab just bought one of those glass rot evap adaptors with screw adaptors so we can screw on any size vial onto the rot evap bulb
The old-school 14/20 septum also fits nicely on 1/4" VCR pipe fittings for UHV stuff.
Cool!
I might opt for a little piece of heatshrink tubing at the top of that temperature probe instead of the electrical tape; less mess, some types come with a glue layer that'll prevent ingress of material at that end, and it provides a bit of strain relief to keep the wires from breaking there. Not really any slower provided that you've got a heat source nearby, as well.
yeah we didn't have any, otherwise yeah - heatshrink is great
Very interesting video! An alternative to Armor Beads/heating oil that I've used is a sand bath. Something I was wondering, how do you usually carry out light sensitive reactions? The sort that must be done in the dark, rather than under certain wavelenght
yeah usually aluminum foil the crap out of the reaction
My brother in Christ, aluminum foil is your friend. Great for insulating too.
I saw the armor beads tip, absolutely agree! My university swapped over to using copper BBs in metal dishes from silicone oil in evaporating dishes in recent years to avoid all the messy cleanup (the BBs may have been cheaper than armor beads, haven't looked their price up myself recently lol)
Seriously, the floors of my lab will literally always squeak from years of oil spills. I want to try to convince my PI to buy me aluminum beads.
I am used to oil when doing reflux/distillations. Pretty much for little inconvenience (one paper towel to wipe the RBF afterwards), you get superior heat transfer, and it is very significant difference in comparison with beads/block. Because you can stir the oil inside the bowl. You cannot stir metal beads. Heat transfer isn´t the best, also the same apply for aluminium heating blocks. But it is pretty, nice to work with, and clean - for regular reactions, when heat flux to the RBF does not matter that much, superior :)
@@jakuborvos1575 I usually have to use two paper towels at least for ~100 mL flasks to get the oil completely off, and 3+ towels and one soaked in hexanes to get it off 250 mL flasks. I've also had oil spill in the fume hood so many times that I just seriously dread cleaning up oil ever again.
You can clean NMR tubes by combining a Soxlet apparatus and one of the described setups in one device. By that, hot solvent is rinsed through the tube multiple times automatically. If there is interest, I can dig out the patent number (already expired) with a picture.
Yeah I tried this, but the desiccator method works much better
@@That_Chemist Please show it in a video. I do not know this one.
The method with boiling solvent has the advantage, that the solvent is almost at the boiling point, where its dissolving power is usually the best. And it runs basically forever, as it recycles the solvent. In some cases, I left the tube in there for an hour, which led to many flushing cycles.
We've used copper plated steel bb pellets for high temperature baths before. Their smaller size makes for more contact area. Crazy cheap and readily available at least in the US. I think we got ours from the sporting department in Walmart.
I use a piece of 7 or 8mm glasstube that I drew a bit longer and sealed at the end (under flame of course). As it is similar in size that thermometers, it fits standard thermometer adapters. Insert a wire thermocouple to the end and it works a treat. (some sealant perhaps to make it not fall out by itself). A glass pipette with sealed and should work pretty similarly if you have them in suitable size and lenght.
Similar to your septum idea but this works with any standard adapter which I find very convenient.
Great suggestions!
I've used the reservoirs before. I was working in a biotech research lab, and they had one for some reason. Worked very well.
One lifehack that I used to circumvent having to make capillary tubes was to use a blunt needle instead for spotting TLC plates. To reuse you just wash them in some solvent.
Yeah so I’ve tried that, but I found that it scratched the TLC plate more - maybe I dinked it up though
@@That_Chemist I've never had problems with that, I was always scared to make the spot too big so I gently tap it once or twice
We use 1-5μL capillary pipettes (Hirschmann Ringcaps). They're ideal for TLC spotting and you can get a pack of 250 for 30 bucks, which is just over 10ct per capillary. If you reuse capillaries, a pack of these can easily last you a year or two.
Just use both-end-open melting point capillaries
PEG-3000 makes a good substitute for oil in an oil bath--solid at room temperature, no mess, easy to clean. Melts at 60C and usable up to at least 250C.
interesting!
Wouldn't you risk peroxide formation by heating PEG under air, especially if you reuse it?
@@mathiasdaniels Maybe, never been an issue. It does get a little brown with reuse but it's cheap so easy to toss and use a fresh batch.
I‘ve seen metal baths before. It was a bunch of low melting metals (really nasty and toxic stuff too I believe), solid at ambient temperature, got liquid at about 250 and boy could you heat them up. The silicon oil doesn’t handle temps above 300 C well but the metal didn’t have any problems.
For what you would need temps up to 500 C in a normal organic chemistry lab though is beyond me
@@floriaborn A tin bath would be a cheap and pretty non-toxic replacement, but you would have to skim the oxide off occasionally.
I wonder what the thermal transfer difference between a bath of armor beads (or copper bbs) would be compared to a sand bath since sand baths take a while to heat up and hot plates usually say not to use sand baths since they are somewhat insulating
either way sand baths are my go to for now, until I get a heating mantle (or rather should I say buying the heating mantle element and mounting it into a crock pot shell because its cheaper and looks funny)
@@EdwardTriesToScience I think sand baths would be a good order of magnitude poorer at conducting heat, but if it works then hey.
Sand is super safe if you break a flask too, really can't beat it for some stuff.
I like cleaning NMR tubes using pipe cleaners. Mostly because I worked in a polymer lab and gels don't like to be removed with a solvent rinse, but also because it's the intended use of a pipe cleaner (as opposed to arts and crafts).
I just hate it when it leaves gunk behind - if you use them more than once, they rust and make the nmr tube nasty
@@That_Chemist I had a friend that would solvent clean NMR tubes and just put them on an argon line to dry. Granted he was in medchem but it was suuuuper convenient
@@That_Chemist Shouldn't be rusting if you are just using organic solvents.
You could use an induction heater on those armor beads too, in theory at least.
For the amour beads, I use a cheap aluminum pot from the grocery store. Works just as good as one from Armour bath itself that a lab in my building has.
Instead of armour beards one can use Al-folio. Al-folio can easily be shaped to fix your flask or vial and seat on the heating plate.
Lol I have a few of those, however I don't find the thermal transfer as well as expected, it works well as a crude heating block nonetheless
Just today I was thinking about how to build an NMR Tube cleaner and now I see this video. Thanks!
Glad I could help!
armor beads strike a chord. back in the day, I used copper shot.
cool!
Awesome channel! Could you please include the NMR tube cleaning hack that you mentioned in one of your next videos? Thanks.
This puts a smile on my graduate life.
Need aluminum heating blocks? Visit the university's machine shop and mill it to whatever shape you want. You can make fairly specialized ones for a few bucks in aluminum. Swap metal treating chemicals or demos of anodizing for the machine time. They really enjoyed the demo of colorful anodizing of titanium. ❤
I like the aluminum heating blocks so much. Several companies sell them now for all sizes of vials/tubes/flasks, so I never want to go back to using oil baths. I think it is also cheaper long term because you probably never have to replace them. One thing that could also be nice if your lab has enough money is a "Findenser", no more running water or a recirculating cooler needed for reflux reactions, but they are expensive.
yeah findensers look cool but I haven't tried one before
@@That_Chemist We had a demo once, they work well if the solvent you are using is not too volatile.
It would take a very long time for me to trust doing reflux with one of these. My first thought is that the "cooling air" would actually be the hot air rising from the hotplate and reaction flask...
Those Findenser look nice. And we have to spend some money. What do they cost approximately?
We use a Findenser from Heidolph. It's awesome! Can't break easily, can't roll off the bench, can be clamped easily, and also has an additional coolant reflux layer inside in a secondary containment. They're great for medium-boiling solvents, I *think* anything below 40°C is tough but eehhh
TH-cam: hey wanna learn useful information for working in a laboratory?
Me, someone with only very basic knowledge on chemistry and absolutely zero desire or plans to start studying for a career in the lab: why yes thank you that sounds handy!
:)
Have enough aluminium foil and glass fibre insulation material for a high temperature distillation or reaction so it won't take multiple days
Check the quality of the vacuum and have a backup pump
Be gentle to any pH measuring probes
life hack, levitate a stir bar above your magnetic hot plates!
I've used the septum trick but I was never super happy with it. There's always some condensing solvent pooling up where the needle sticks out and if it's something like DCM the septum will not last very long. Plus it gets all over your gloves when you pull of the vial. I've had more success with a big hole in the septum to allow backflow of the solvent.
Usually if you pull vacuum long enough, and of the gathered solvent will evaporate - even if the solvent causes it to swell, it will unswell once it evaporates
There's a much simpler way of making a more resilient and reliable NMR tube cleaner: Get a big Buchner flask and find the largest rubber septum you can fit into the neck. Then find a needle longer than any of the NMR tubes you need to clean, and poke this up through the septum from below before fitting the septum to the flask. Alternatively you can use a broken off section of old stainless steel cannula - works in the same way.
Then when you want to clean the NMR tube, invert it and feed it over the needle, so the tip goes right to the end of the tube, and the mouth of the tube is below the rim of the septum. Apply a half-decent vacuum to the flask (house vacuum or a water aspirator is fine for this), and then squirt whatever solvent you want to use for washing the tube into the top of the septum. Works in more or less the same way as those fancy and expensive glass syphon NMR tube cleaners, but since there are no delicate thin bits of glass involved, it won't break so easily.
The vacuum draws the liquid up the entire length of the NMR tube, then down the needle and into the flask. The sequence we used in the lab I worked in was: Acetone first, then a bit of dilute hydrochloric acid, then deionized water, finishing with more acetone to chase the water out. Once the flask is full, just remove the septum and pour the contents down the sink. Or if your lab doesn't allow you to pour acetone down the sink, substitute IMS or IPA instead, since these are usually more acceptable to go into wastewater, at least as I understand it.
Cleaning tips would be good 👍
100%
we just wash our oil with some hex/ether/chloroorg, no wiping nedded. but aluminum chunks seems cool, i need to try.
How have I been living without a metal pellet bath?!?
Right now buying some aluminium balls, I might try mixing in some finer pellets to optimise the packing density and hopefully get that thermal transfer even higher.
Wish I could afford copper balls...
I use beach sand for heat bath instead of metal beads. Those beads are heavy.
It’s a really poor thermal conductor though - that’s the one issue with sand
Great chem life hacks! Is it still possible to buy those older rubber septa that fit more snugly for convenient rotovap use?
I have really struggled to find any - if you do find a vendor, and successfully receive some of the correct ones, please share it in the discord! There are similar-sized bumpy red 19/22 ones that you can get from aldrich which also work!
you know, they have rotovap adapters that screw into vials of all sizes.
If you wrap the thermocouple end to aluminium foil, you are practically reflecting IR from the probe... That is the reason why we wrap columns and flasks with Al foil during distillations - to insulate them.
If you aim for superior acuracy and lowest possible heat capacity of the probe (quick equilibration of reading), invest in Pt/PtRh thermocouples or Pt100 probes (with suitable digital reader). You can put them bare/uncovered inside, and there is little to none ordinary chemicals/compounds that could etch them.
Also, classic K probes or J probes for thermocouples are similar chemical resistance than stainless steel, so they are perfectly suitable for distillations of wide array of compounds. Avoid any HCL or acids from them and they would serve you lifetime.
I tested it without the aluminum foil and with the aluminum foil and the response time/sensitivity was faster when I had the foil
Thanks for the information. Please post more videos like this one
Will do :)
How hot can I heat using such beads? I want to do a vacuum destillation of a silane at 160 °C. Would d~3mm copper grains from EBay be suitable for this?
Yeah probably
In the labs I have been at we usually had 3D-Printed adapters for Vials to either 29/24 or whatever the small one commonly used is 14/20 maybe? (both of them Female of course).
That way we could connect them to the Schlenk Line and the Rotovap. Of course, Schlenk line is a "Welp, didn't pay attention for a minute and into the base bath my line goes..."-hazard...
What type of plastic do you print with?
@@That_Chemist Sadly I don't know. I just used those at my internships during my Masters.
What kind of metal would be best for a bead bath? The armor beads are stupid expensive, if the metal holds cold well too this could be better than using ice!
You could probably toss in some dry ice in the middle and have great cooling. But dry ice isoprop is not messy so…
@@floriaborn I was thinking about have two metal dog bowls filled with aluminum shot in the freezer. Just swap them out when one gets too warm
I also regularly did dry ice armour beads, but I often did it with acetone as well - as soon as the dry ice melts, the whole thing sinks which isn’t ideal - this is the one reason why acetone/dry ice is superior
its kinda funny that the most expensive part of the diy digital thermometer is probably the NMR tube itself. the TM-902C is like $5-$20 depending on where you get it (and usually they throw in a couple thermocouples in for free) but NMR tubes are like exorbitantly overpriced ranging from like $5 a tube to like $20-$30 a tube.
they can cost as low as $1, but lots of customers are getting fleeced
@@That_Chemist i guess it does help when youre not buying them with your own money, rather an institution/colleges money.
More of these please.
I've used the septum roravap hack. I parafilm the septum and the vial since I've had vials fall into the water bath.
you just need to use more virgin-septa - the well-used ones get too loose
Could you send me a link to the thermocouple amazon listing?
its in the video description :D
@@That_Chemist Thank you!!
Hi. Do you know a vendor who makes/sells viton septa of 14/20 assorted sizes? I believe by "rubber" you're referring to BUNA-N?
I'm not sure, but you could ask ppl in the discord!
Best way to clean a dirty NMR tube could be just to throw it out and pick a new one 😂
Tier Chemist: Do you trust me?
Me: With every cell of my body
I hope you have a great day too! Thank you
:)
Tigon tubing? Is there also Liger tubing??
Liger-pattern tubing would be pretty cool
Septa look like mario tubes with venus fly trap.
Lol it’s true
What if I call septa rubber bois. Is that allowed?
oh yeah
Why armor beads bath? Mercury would be combination of oil and metal beads
mercury is volatile
Also mercury is mercury
Have you closed the comment section? I open it and see nothing. 🙁
I'm not sure what you mean?
@@That_Chemist Most likely a bug. Could not see the comments section for some reason. It is OK now. 🙂
I dream about using beads at this point, but have nowhere to get those here. :(
You can just buy copper BBs for hunting or sport shooting, they'll work just the same as long as they're all metal
genius
Amazing
The beads are meh. They make a mess. Also aluminum is more reactive than you think. It doesn't like acid or base. Ask me how I know! Use a water bath for anything
Oh and zip-ties. Get a non-sharp edge by twisting off w/ pliers. Grab it right at the locking piece & twist, until it comes off. Do not pull! They won't scratch you anymore.
The armour beads to have a coating btw - some sort of enamel
@@That_Chemist POCl3 don't care.😀
Poor chemists life hack: cleaning capillary tubes by dumping them in a large beaker containing your favorite cleaning solution (please no piranha), putting it in a dessicator and pulling a strong vacuum for a couple minutes. Let go of vacuum and the solution goes inside the tubes, veeery useful for sealed capillary tubes that go like water in class-labs
That "old school" septum looks just like a 19/22 septum.
It is a 14/20 - however if you get those red bumpy 19/22 septa from Aldrich, those will work as well
@@That_Chemist gotcha, hard to judge size. I tend to use 19/22 septa on 24/40 bump trap on rotovap for vials. The septa eppendorf combo is nice, I've incorporated that after seeing the vid. Cheers
That is how we wash nmr tubes at my university lab
It’s relatively common I think, but good to share nonetheless!
Ex-septa patronum!
K-type thermocouple is inherently somewhat inaccurate to +- 1-2 degrees. I'd recommend to try pt 100 or pt 1000 thermometers. Yes, they are a bit more expensive but you can rely on the reading to be accurate within 0.01 degrees plus the responsiveness is incredible.
its pretty rare that 1-2 degrees matters for synthetic chemists tho
@@That_Chemist I like to monitor the temp when doing solvent distillation so I can be sure that the azeotrope with water has boiled over for example. I like this extra information regarding the purity of my distillate. Also with higherish temperatures (say 150 - 200 C) the platinum RTD greatly outperforms even good mercury thermometers so in some cases can be +-1 C vs +- 0.01 C due to responsiveness and general accuracy of the measurement. I find this extra informative especially when doing quick distillations or small volume distillation.
Is that "old school" 14/20 septa actually a 19/22 ?
Nope! It fits in 14/20 flasks snugly. A nice alternative to the oldschool 14/20s is those red bumpy 19/22s though, which will fit the same way
Guys... you need to clean your NMR tubes????
Hahahaha...
What I do in the lab, normally I empty out the sample from the tubes, put 30 to 40 dirty NMR tubes in a galss tube of cooling trap, fill it with acetone and put it in ultrasonic bath for 30 minutes.
A glass tube of cooling trap has big diameter, tall enough to immerse the dirty NMR tubes, and can be hanged on ultrasonic bath with help of a clamp.
Anyone does like this out there?
Yeah this is another common approach
You can also use a plastic bag for this
Good hacks! For #5, you can simplify the setup by just using an upturned septum directly on the filter flask. See for example: 10.1021/acs.jchemed.1c00337
What makes it even better is that you can jam as many "threads" of Teflon Tube in there as you can manage, so you can clean 1, 2, 5, 10 nmr Tubes at the same time.
@@heulboje21 For sure. If you have even more, you can use the vacuum desiccator approach. DOI: 10.1021/acs.oprd.6b00001
@@Bloviator0 Holy **** I didn't even know something like that was possible. Would've saved me from cleaning all those NMR Tubs during my last internship. Oh well...