Besides the discussion above, I`d like to thank you very very much for your
visit to our group of Geosciences here in Campinas, Brazil.
Our best regards,
2010/12/17 Pappas, Richard Steve (CDC/ONDIEH/NCEH) <[log in to unmask]>
> I agree with Lyndon on concern for subsequent S issues. I have used up to
> 5% H2SO4 with no ill effects on an alumina injector -at least no rapid
> effects. If I were going to subsequently analyze for S, 48Ti, or 64 Zn, I
> would not use it with ICP-MS. However, without cones on an ICP-OES, the
> effect would be less.
> Just as we might use dilute HCl, HF, or H2SO4 to clean certain metals out
> of a system, one could use maybe 50 ppb of magnesium,lanthanum, or cerium to
> aid in sulfate clean out from the introduction system if that would not
> interfere with something else.
> De ferias em Brasil,
> Steve Pappas
> De: PLASMACHEM-L: Analytical Chem.(ICP's, DCP's, MIP's). em nome de Wels,
> Brian R
> Enviada: qui 12/16/2010 5:21
> Para: [log in to unmask]
> Assunto: Sulfuric acid vs. alumina injector
> Dear List,
> We have been running an ICP-OES (Perkin-Elmer Optima 5300 DV) for five
> years, feeding it a steady diet of a few percent nitric and/or hydrochloric
> acid. Just your routine EPA 200.7 and 6010 type of work and everybody's
> happy. Now we are confronted with a project requiring a matrix of up to 10%
> sulfuric acid. Most sample introduction components are made of Teflon,
> glass or quartz. The peri-pump tubing is Tygon and the injector is alumina.
> Some concerns have been raised over the alumina injector suffering harmful
> effects. I know alumina is resistant to chemical attack, but are the
> concerns justified in this case?
> Also, can we expect problems with interferences from residual sulfuric
> after switching back to our routine workload?
> Thanks for your input.
> Brian Wels, Ph.D.
> State Hygienic Laboratory at the University of Iowa
> 2220 South Ankeny Blvd.
> Ankeny, IA 50023
Dr. Alfonso Schrank
Dept. of Energy and Natural Resources
Unicamp (State University of Campinas)