I have used up to 10% v/v sulfuric acid using the standard P-E sample introduction system (cross-flow nebulizer, Ryton spray chamber and alumina injector) without significant problems. Sulfuric acid does seem to corrode the clamp bolts on the spray chamber end cap more than HNO3/HCl. The concern about trace levels of sulfur are warranted, especially on a DV system where the torch is horizontal. I would recommend dedicating a sample introduction system to the sulfuric acid matrix analysis rather than trying to switch a single unit back and forth.
Kingsport, TN 37663
--- On Thu, 12/16/10, Wels, Brian R <[log in to unmask]> wrote:
> From: Wels, Brian R <[log in to unmask]>
> Subject: Sulfuric acid vs. alumina injector
> To: [log in to unmask]
> Date: Thursday, December 16, 2010, 4:21 PM
> 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
> Thanks for your input.
> Brian Wels, Ph.D.
> State Hygienic Laboratory at the University of Iowa
> 2220 South Ankeny Blvd.
> Ankeny, IA 50023