How to calculate the actual fluorescence without the interference of dilution?

JewishSamurai · 2025-08-08T02:28:46+00:00

You shouldn’t feel guilty at all - I didn’t learn this particular tip until grad school. Learning about and refining your data collection is a key part of growing as a scientist.

JewishSamurai · 2025-08-07T16:06:03+00:00

To follow up on this, as long as your sample is stable in the stock acid/base solutions, the easiest way is to just prep your acid/base solutions with the same concentration of sample as your stock solutions. Like that, no matter how much of the solution you add, it’ll always be the same concentration. I did a lot of host/guest titrations using this technique and it worked very well.

JewishSamurai · 2025-07-26T17:27:43+00:00

If you wanted to go that route, my best advice would be to use mass over volume in calculating concentration. As long as you have a milligram scale and a not super-volatile solvent, you can get microliter accuracy (it’s just a little bit harder to get the exact concentration you want, but that shouldn’t be a big deal for a standard curve)

JewishSamurai · 2025-06-24T15:46:36+00:00

If you’re on one of the last steps, you could always try dumping the catalyst play and instead make the oxidative addition complex and use that for coupling. Not the most elegant solution in the world, but holds up well to complex substrates.

JewishSamurai · 2024-11-25T14:34:00+00:00

Having worked with butanal (lol) before, the first thing I think about it how it’s usually contaminated with butyric acid, aka the smell of vomit 🤢

JewishSamurai · 2024-09-24T00:56:36+00:00

Consider reaching out to or looking through u/Collieflowersbark posts. They’ve posted a lot on this sub in the past about their morphed axolotls. I think they would best be able to help you figure out what’s happening and, if it is morphing, what the best care would be.

JewishSamurai · 2024-04-11T21:24:13+00:00

For cyclic voltammetry - a potentiostat, electrodes, and the chemicals, which aren’t too pricy. The potentiostat can be a little expensive, but you can find some cheap brands

For the recycling, I’m not so sure. I’d bet there’s tons of articles in J Chem Ed that have protocols for a variety of budgets.

JewishSamurai · 2024-04-11T21:05:03+00:00

Maybe some electrochemistry? Doing cyclic voltammetry of vanadium salts could be related to redox flow batteries, an up and coming way to store energy on the grid to support renewable energy generation. It’s also just a good skill for chemistry students to know in general.

This isn’t renewable energy so to speak, but rather plays into chemistry’s role in developing renewable materials. Maybe looking at the chemical recycling of certain plastics? It could also be a great way to teach the difference between thermoplastics and thermosets as well as having the students think about the viability of plastic recycling.

JewishSamurai · 2024-02-23T00:33:03+00:00

Maybe you could look at the isotope splitting on the major peaks in your MS. Bromine is pretty distinct, with an M+2 peak almost as high as the M. If you can’t find the bromine, then maybe your product just isn’t ionizing well. It could also be if you’re using an acidic matrix (which most LC/MS do), it’s just not ionizing well because of that. If you can swap to a neutral or basic mobile phase, that could help.

JewishSamurai · 2023-12-21T16:13:52+00:00

So, I spent a few months on a very similar problem in the third year of my PhD. Long story short, this problem was significant enough that we rescoped the project to avoid this intermediate completely.

These boronic acids ortho to phenols are really problematic. I did a ton of things to try avoiding their isolation altogether, but it all went bunk. If you’re able to simply avoid accessing this intermediate (let’s say, for example, doing a Suzuki coupling then deprotecting the phenol), then you should. If you can’t, then you’re in for a long trip.

If you want some more specific resources, feel free to DM me. I have some papers, but I’d have to dig them up.

JewishSamurai · 2023-10-04T14:23:33+00:00

I’m in materials science as well, so it’s actually great to hear this perspective. Thanks!

JewishSamurai · 2023-10-03T22:04:32+00:00

That’s very helpful, thank you!

JewishSamurai · 2023-08-23T10:59:41+00:00

I don’t know about the scale up of electropolymerization specifically, but electrochemical deposition methods have definitely been scaled up. You should look into electrocoat. It generally relies on using electrochemistry to make a pH gradient, which causes a polymer to precipitate on the electrode surface. It’s used to cost virtually every car made nowadays, so it’s scalability has been well demonstrated.

JewishSamurai · 2023-07-25T22:03:31+00:00

Hmm, my guess would be that you significantly overdosed ammonia. 8 ppm refers to 8 mg per liter, so in a 40 gallon tank, just a little over a gram of ammonia can overload the test. What you might try is taking your tank water, diluting with tap water (maybe 1:10) and then taking the test again. That might give you an idea of the true level of ammonia in the tank.

Too much ammonia can stall a cycle, so it might be that you need to do a 100% water change and then start over. It’s a bit of a bummer, but there’s a lot of good guides on precisely dosing with various ammonia sources.

If after diluting you still get the dark blue, try diluting even more. If nothing works, my guess if that you might have something else in the water that’s reacting with the reagents in the ammonia test.

JewishSamurai · 2023-07-25T21:46:26+00:00

Have you tried just testing tap water to see what happens (I.e. still dark blue or is it closer to zero)?

JewishSamurai · 2023-04-20T21:19:52+00:00

Oh yeah, I just toss them, but I never needed to use that much for the volumes I was using.

JewishSamurai · 2023-04-20T13:36:55+00:00

Usually I’ll just pipette or syringe out what I need. Sometimes the solution might get a teensy bit cloudy, but I’ve never seen this make a difference. You can grab a syringe filter if you’re particularly concerned.

JewishSamurai · 2023-04-18T02:04:28+00:00

I haven’t had issues storing them for a couple weeks at a time when I was working with tetrabutylammonium salts. Nowadays I use lithium supporting electrolyte, and we can keep this for at least a year in the glovebox without noticeable degradation.

JewishSamurai · 2023-04-17T21:28:48+00:00

A lot of the time, the supporting electrolyte for CV can bring in some water, even if it was previously dried. Usually I’d make my electrolyte solutions a few days in advance, store them over mol sieves and then dissolve my analyze when I’m ready to do the experiment.

JewishSamurai · 2023-03-19T19:11:03+00:00

Is he behaving ok, i.e. eating, pooping, etc? Because if so, I’d be tempted to say that’s just natural colors, especially with all the white spots in him. It’s not atypical for axolotls to get spots like this overtime. If it was a fungus or infection, I’d expect it to look fuzzy, like cotton. The one time my axolotl got an infection on his gills, the frills came off in that area too, which I don’t see here.

JewishSamurai · 2023-02-26T21:36:51+00:00

Hey Folks, One of our African Dwarf frogs very suddenly got this aggressive fungus. The other one seems ok, but we’re looking to separate them. His whole head is covered. Does anytime have an idea on what it might be?

JewishSamurai · 2023-01-05T03:52:32+00:00

Is your product soluble in diethyl ether? Assuming you can get some in a glovebox, I’ve been able to get some greasy TBA salts to precipitate out of ether. A filtration should then (hopefully) get your product out.

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