Sciencemadness Discussion Board

Quantitative Sulfur Detection

Hang-Man - 14-5-2008 at 19:57

I was wondering if anyone had any experience or insight into extracting and quantitatively measuring elemental sulfur. In my case I’m looking for it in recycled vulcanized rubber but any general ideas would certainly be helpful. The only method I’ve found is combusting it under oxygen and passing the exhaust through an IR cell (to detect the dioxide), while that isn’t beyond the scope of this project I’d prefer something less elaborate and easier to calibrate; a method to extract it all to the same salt so I can run ion chromatography for example.

The rubber has been treated with high pressures and heat to break most of the cross linking, what exactly the process is I am unsure, however it is safe to say sulfur is present in many forms. I expect levels of 1-2% and have no rubber standards of known sulfur concentration with which to calibrate, so it important the extraction is complete.

Any ideas?

ShadowWarrior4444 - 14-5-2008 at 20:13

Hmm, boiling with NaOH to sodium polysulfides may work. To test the concentration you may try to use a similar electrochemical cell to a Sodium-Sulfur battery. This would probably be quite inefficient though, other ways of testing the sodium polysulfide concentration might be more advantageous.

Perhaps some attempt at leaching the sulfur out using the organic/hydrocarbon solvent of your choice.

Hydrodesulfurization is also an option:
http://en.wikipedia.org/wiki/Hydrodesulfurization

[Edited on 5-14-2008 by ShadowWarrior4444]

not_important - 14-5-2008 at 20:25

might look at this - old but gives a background

The Analysis of rubber By John Betley Tuttle
http://www.archive.org/details/analysisofrubber00tuttrich

JohnWW - 15-5-2008 at 00:51

Quote:
Originally posted by not_important
The Analysis of rubber By John Betley Tuttle
http://www.archive.org/details/analysisofrubber00tuttrich

(Chemical Catalog Company - 1922)
Here are direct downloading links for it:
ftp://ia340913.us.archive.org/1/items/analysisofrubber00tutt... or
http://ia340913.us.archive.org/1/items/analysisofrubber00tut... 22.95 Mb or ftp://ia340913.us.archive.org/1/items/analysisofrubber00tutt... 5,294 Kb
Other formats including raw image scans available in ftp://ia340913.us.archive.org/1/items/analysisofrubber00tutt...

Hang-Man - 15-5-2008 at 11:19

Thanks for the book, I gave the sulfur chapter a quick read and it looks interesting (although conc. nitric saturated with bromine sounds a little evil) I found a journal of chemical education article detailing detection through ion chromatography however I dont have direct access to it here and have to wait for it to be sent from another library.

I've seen some mention of S detection though ICP, and I can purchase ICP sulfur standards indicating it is possible. I've only used that instrument for metals though and I've never seen it applied to anything like sulfur. I guess I still have the same problem of getting all the sulfur into an aspiratable form... Lots to think about.

Thanks for the help.