Sciencemadness Discussion Board

Methods for Identifying Chemicals

aab18011 - 5-6-2020 at 19:05

Hi, I am new here and I am setting up my own personal lab. I have quite a lot of starting equipment that I have bought or received as a gift. However, I plan on doing my own reactions and trying to modify syntheses, and some of my products come out so different that it is hard to determine what chemicals I am making. I was wondering if there are some nice machines that can be used for this. I mean I don't want to spend 20,000$ on an NMR machine, but I have heard from the grapevine that you can find one for cheap. For example, I was working with Tannic Acid in hopes of breaking off the Gallic acid units with Sodium Metabisulfite. My problem is making sure that my products are what I predicted them to be.

Bmoore55 - 5-6-2020 at 19:41

I could analyze your samples for you. I have my own lab with and NMR, FTIR, and GCMS.

aab18011 - 5-6-2020 at 20:17

Quote:

From: Bmoore55
I could analyze your samples for you. I have my own lab with and NMR, FTIR, and GCMS.


I would be interested in that, but I'd need to check state laws for sending packages like that. My own school lab offers the service, but its expensive even for faculty. Some charge like 200$ for a small batch of samples.

Ubya - 6-6-2020 at 00:42

for amateur chemists analysing their compounds is the hardest part, you could use wet chemistry sometimes, but you can never be sure 100% to what you have.
you could try with an used MS system, some of the members here have one, or multiple instruments, but still, complex molecules can be hard to identify, expecially if you are dealing with a mixture.

arkoma - 6-6-2020 at 02:09

Quote: Originally posted by aab18011  
Quote:

From: Bmoore55
I could analyze your samples for you. I have my own lab with and NMR, FTIR, and GCMS.


I would be interested in that, but I'd need to check state laws for sending packages like that. My own school lab offers the service, but its expensive even for faculty. Some charge like 200$ for a small batch of samples.


Hello? State law does not cover US mail. Troll?

aab18011 - 6-6-2020 at 10:01

Quote: Originally posted by arkoma  
Quote: Originally posted by aab18011  
Quote:

From: Bmoore55
I could analyze your samples for you. I have my own lab with and NMR, FTIR, and GCMS.


I would be interested in that, but I'd need to check state laws for sending packages like that. My own school lab offers the service, but its expensive even for faculty. Some charge like 200$ for a small batch of samples.


Hello? State law does not cover US mail. Troll?


No no, I'm not troll. I am pretty serious about this too because I am trying to put together a research proposal and give it to my advisor, but I need proof that my syntheses are correct. I was supposed to be working on a way to use indole as a carrier for various ligands our lab is interested in.
Quote:

for amateur chemists analysing their compounds is the hardest part, you could use wet chemistry sometimes, but you can never be sure 100% to what you have.
you could try with an used MS system, some of the members here have one, or multiple instruments, but still, complex molecules can be hard to identify, expecially if you are dealing with a mixture.

Yeah, I was thinking about the wet chem identification, and I will be using some methods. I need to wait until I can acquire some more chemicals, Sigma makes using dept. based discounts a nightmare.

neptunium - 24-9-2024 at 12:54

anybody interested in some GC/MS analysis ?
https://www.youtube.com/watch?v=R4uNld5OAaQ
I guess I should`ve posted here first!
https://www.youtube.com/watch?v=2F4z26C9mkI
i don`t stop by as often as I used to but ... here you go..

leaded gasoline 100LL.bmp - 5.9MB

[Edited on 24-9-2024 by neptunium]

neptunium - 24-9-2024 at 13:05

This is the Thermo Finnigan Trace 2000 combo as explained in the vids..


Snapshot - 14.png - 5.8MB

Sulaiman - 24-9-2024 at 23:47

Quote: Originally posted by aab18011  
Hi, I am new here and I am setting up my own personal lab....
I plan on doing my own reactions and trying to modify syntheses, and some of my products come out so different that it is hard to determine what chemicals I am making. I was wondering if there are some nice machines that can be used for this......

My problem is making sure that my products are what I predicted them to be.
welcome:)
The instant that you deviate from a published procedure in the minutest detail,
good luck predicting products :P
Maybe tlc or mp are suitable in this specific case?

I'm still only doing entry level inorganic chemistry and I'm rarely confident of the purity of my products.