From Lab to Backyard: How Is DEET in Bug Spray Made?

[@johnathancorgan3994]

Multi-step laboratory scale synthesis, voice narration, no music, TLC reaction monitoring, column chromatography purification, GCMS product characterization--you're setting a new standard for youtube chemistry videos. Thanks.

[@WheelerScientific]

Glad you enjoyed. I love NMR but you just can't beat the data from a GCMS, I am working on getting an LCMS-TOF going, power has been ran for it, just need the software now. I cannot wait to put it to use, opens the door for a lot of projects.

[@davidfetter]

@@WheelerScientific I'm picturing your NMR project. "What do you do with a 50T magnet? NMR!"

[@AppliedCryogenics]

Thumbs up for using Predator as a visual aid.

[@ChemicalEuphoria]

top tier video quality, top standards! keep up the good work bro!

[@wesleymccravy901]

Sure is a lot of predator footage for this comment.

[@ChemicalEuphoria]

@@wesleymccravy901 sorry?

[@h68-v7d]

Nicely done, overall. Few questions and notes: When doing TLC, generally you want to use a closed chamber and let the vapors equilibrate. Use a jar or cover the beaker with a watch glass. Otherwise, your spots will skew upwards and your Rf values will be unreliable. I have a hard time seeing your starting material. If the box said fluorescent TLC plates, why not use UV? The toluic acid should detect. You don't need glass wool in that column, because it has a fritted filter plate. With the glass wool you will just get an uneven surface at the bottom, which is not good. When you put the solution onto the column, it looked like there were two layers? Is the product soluble in hexane? Also, methanol is not miscible with hexane. Generally, you want all eluents to mix with each other when doing gradient elution. The product does not visually look purer than before chromatography. I think the tar gets stuck on the precolumn of the GC and thus the machine can not detect it.

[@WheelerScientific]

Thanks! Yeah, I forgot the lid for TLC; if I were doing more complicated detection, I would have thrown it on. I tried to use UV, but it didn't show up on camera, so I used iodine to give a more visible look. I've had a problem with columns letting alumina through, even with fritted bottoms, so I always throw some glass wool in. The DEET gets stuck to the alumina, so I did it the way I did; the hexane washed out with everything impure, and then I added methanol to strip the DEET from the column. For GCMS, I did a pre-test on the NMR and got perfect results with no noise and only one random peak up-field (Probably water), so I went ahead with GCMS. There is likely a bit of tar, just a negligible amount, but enough to darken the sample. I could have thrown some decolorizing carbon in it and taken care of it. Thanks for the comment and input. Hopefully, I have explained why I did everything well.

[@h68-v7d]

@@WheelerScientific Okay, fair point about the spots being hard to see under UV on camera, I also encounter that issue frequently. Usually taking a picture and increasing the contrast in image software helps though. I guess the impurities that discolor the DEET must be present just in traces, if there isn't anything in NMR. Overall I am impressed by how well the purification worked given the fairly unorthodox technique and when it visually really doesn't look like it. The result is great, really, I hope my comment didn't sound too much like criticism. The analytical work in your videos is inspiring.

[@WheelerScientific]

No worries at all and thanks. Yeah, I was quite annoyed when the DEET got stuck in the column, I ran the reaction four times to make sure it wasn't something I was doing wrong, when the procedure I was following set it would pass all the way through.

[@tracybowling1156]

I always assumed that Deet killed insects. That'l makes no sense, though. If you really think about it. I learned this a couple of months ago when I still lived in Florida. I sprayed insect repellant onto the mosquitoes. It did absolutely nothing to them, so I Googled it. I learned exactly what you told us. That Deet masks our "smell" to biting insects. Pretty interesting!

[@IanJohnstonblog]

Awesome video… the only complaint was the seizure inducing flickering from the beat frequency of the lights and the shutter speed.

[@WheelerScientific]

Thanks, yeah I cannot really fix that without an investment in different lights, its just the time-lapse causing it. I imagine there's also more settings I need to adjust.

[@Cooowop]

very interesting will be finishing this vid later 👌good work

[@azraellie_]

Interesting similarity in structure to some novel stimulants. Well, intersting to me anyway, considering what this one kid did this one time at cadet camp (basic survival, not band sadly). We were given insanely high concentration bottles of DEET because we were staying in Ontario woods for a week or so during a heat wave after it had rained for days in a row. We were told not to apply it directly to our skin, and that the bottle had to last us the whole trip. Well, this one dude went around stealing peoples bottles, claiming you could get high off it (no idea where he'd heard that from, likely one of the sargents was a chem student). He was spraying it in his mouth, even, i watched him do it. He didnt sleep for several days, got sent to base for a medical check up, then sent home and we werent allowed to talk about it anymore. Wouldn't be surprised if hes dead now 🙃 Oh, Blackdown Lima Sq. 2015, I'll never forget you my beloved ❤

[@henricoderre]

More importantly, does DEET really keep bugs away? I seem to remember using it while in the woods. There may have been less mosquitos attracted to me, but I still got bit.

[@MIH0319]

Very nice synthesis! One question, as the reaction between the m-toluyl chloride and the diethylamine releases HCl as a byproduct, is it necessary to add 2 molar equivalents of diethylamine to quench the HCl? (You only added less than 1 equivalent in the video)

[@WheelerScientific]

HCl is a gas, most of its just leaves. You could mix in the diethylamine with an NaOH solution, but I didn't notice any different yields when I tried it that way.

[@petevenuti7355]

Does thionylchloride work for replacing carboxylic groups with chlorine on other compounds say citric acid or other things that have three or more carboxylic groups and may have some steric hindrances?

[@kevinmarrs3372]

Wonder why the Rebemide was in your purified product but not in the crude.

[@WheelerScientific]

Could be a few reason, column interaction, could have gotten stuck to the column and not came out before. Could have been obscured by another sample, or did some chemistry in the gcms.

[@davidfetter]

Gorgeously done! Also, preparative chromatography is not an easy technique, generally. Kudos for showing it!

[@chemicode]

Damn this is pretty cool❤

[@mikegLXIVMM]

Now, let's make some DDT. 😄

[@MattsProductions]

Very cool video. How did you obtain the diethylamine?

[@WheelerScientific]

Thanks. Yeah everyone wants to know how to get the fun chemicals. lol It was just in stock in our dept. from previous needs of it.

[@MattsProductions]

@@WheelerScientific Oh yeah, you are in college sorry

[@WheelerScientific]

You are all good no worries. Did you have any other questions? I would be more than happy to answer those as well!

[@niteshades_promise]

i feel like im getting cancer just watching this... tea tree oil is safe. 🍻

[@jeremycrochtiere6317]

It is harmful to humans its classified as a neurotoxin in concentrations above 90%. While not particularly deadly like it is to insects, it's still capable of Causing harm through it's direct exposure. Including causinh neurological problems from prolonged excessive exposure. So please don't say it's safe, Look up the MSDS on DEET before making your own conclusions.

[@WheelerScientific]

Yes, DEET in very high concentrations with repeated exposure will cause issues. Do you know what else in enough quantity will cause severe issues? Dihydrogen monoxide (water). Pretty much anything in high enough quantities will cause problems. After about 50% concentration, DEET gives diminishing results, so barely, if any, use higher percentages, most use lower 10-30%. The EPA has not identified any risks concerning human health; normal use of DEET products does not cause health issues, except on highly infrequent occasions. Also, DEET doesn't kill insects, which I explained in the first two minutes of the video, just after I said it was safe. MSDS are beneficial, but you can't always correlate a chemical MSDS at almost 100% to a topical solution at a quarter of its amount.

[@niteshades_promise]

brain damage n cancer, dont believe the lies that its safe. the fda is bought n paid off. ​@@WheelerScientific

[@joshuaolander201]

That's scary when I was a kid we used to use a product called muskol that was 97% deet we thought it was great because one 2 oz bottle would get the entire family through a summer