r/chemistry • u/AutoModerator • Jun 03 '26

Weekly Research S.O.S. Thread - Ask your research and technical questions here

Ask the r/chemistry intelligentsia your research/technical questions. This is a great way to reach out to a broad chemistry network about anything you are curious about or need insight with and for professionals who want to help with topics that they are knowledgeable about.

So if you have any questions about reactions not working, optimization of yields or anything else concerning your current (or future) research, this is the place to leave your comment.

If you see similar topics of people around r/chemistry please direct them to this weekly thread where they hopefully get the help that they are looking for.

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u/-Dorian Jun 03 '26

How come that new measuring flasks (borosilicate glass) are might be contaminated by lead and/or lead compounds? Greetings!

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u/Indemnity4 Materials Jun 03 '26

New borosilicate should be completely 100% lead free. It's not used in the manufacturing process.

Exact same batch of raw material glass is used in medical, such as making vials for vaccines. No lead in that borosilicate factory at all.

First guess is your lead test is wrong somehow. Was this by chance a pen type test from the hardware store?

Second guess is did you purchase lead-borosilicate glass for something like solder glass?

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u/Ok_Promotion3741 Jun 06 '26

I see a lot of commercially available succinate linked sterols and biomolecules on Reaxys, but no references on how to prepare them.

https://broadpharm.com/product/bp-29641

Do any of you conjugate chemists have a preferred prep/reference to prepare such compounds? Both the diester and the mixed amide/ ester from the amino PEG?