ICP-OES sample digestion

Question

Hi All, 
 
 I was wondering if anybody knows of any good go-to resources for sample digestion methods? Any ideas are appreciated. I have currently looked through ASTM digestion methods but couldn't find anything suitable for our application. 
 
 On that note, we have an aramide polymer we want to analyse for S content, but I am concerned about the loss of analyte with H2S evolving after microwave digestion. If anyone with experience with sulfur analysis could chime in on whether or not this is a genuine issue I would be grateful :-) 
 
 Cheers!

carwogill · Accepted Answer

Hi, 
 We use a CEM SPD instrument for acid digestion. When I want to digest an unusual (for me) sample I always look first in the CEM.com website. Under resources/ method notes there are a lot of different products listed with acids used plus temperatures. Maybe you can tweak something from there for your specific instrument. 
 I analyse a lot of sulphur in oleochemical samples, and I always digest 500mg in 10 mL nitric acid in a closed vessel SPD system. I never loose any sulphur. However, I think this depends greatly on the initial compound in your sample. In the past I once did a few different spikes of sulfuric acid together with my sample in a microwave digestion, and the recovery was 0% . 
 I analyse sulphur on mass 32 or 34 with xenon as a collision gas. Because I am forced to analyse 100x diluted samples (because of sample prep) my quantification limit is something like 2/ 3 ppm S. For digested oleochemical I use an internal standard solution with added IPA. This will enhance the S sensitivity. 
 Hope this will help you a little. 
 BTW I use an ICP-MS!!

ICP-OES sample digestion

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