We found that a 50/50 mix of IPA also extinguished the plasma in our 7500a system. In fact it melted the torch and I think the person working on this projected resorted to something entirely different. Some time before we successfully used a 10% aqueous IPA solution as a rinse for samples suspected of containing traces of fatty acids.
ABC Laboratories, Inc., 4780 Discovery Drive, Columbia MO 65201.
Tel: 573-777-6012; Fax: 573-777-6090
Integrated Chemistry and Biology Services for Product Development
From: PLASMACHEM-L: Analytical Chem.(ICP's, DCP's, MIP's). [mailto:[log in to unmask]] On Behalf Of Julia Spraul
Sent: Tuesday, December 21, 2010 8:59 AM
To: [log in to unmask]
Subject: Tertbutyl hydroperoxide (TBHP) analysis
I searched the archives for this before posting and did not find any info there, so here's some background on a problem I'm currently trying to solve. Any suggestions of things to try are welcome! Thanks in advance!
I have samples that are ~45% tertbutyl alcohol (TBA), ~45% tertbutyl hydroperoxide (TBHP), with the balance of water and iC4s. I'm trying to analyze these samples for corrosion metals (Fe, Cr) as well as Mo, Na, and P by ICP-AES. I've previously been able to analyze 20% TBA in water with no problems, however when I try to analyze these samples at a similar dilution, the plasma-Z is exceeded and the plasma extinguishes. I have also diluted the samples in isopropanol and had the same problems. We have a Perkin Elmer 5300 DV ICP. Settings used were 1500W, Plasma gas 15 L/min, Aux 0.5 L/min, Neb 0.45 L/min. 1.2 mm quartz injector, baffled cyclonic spray chamber, Meinhard C1 neb, flow rate 1.5 mL/min (tried lowering this too, with same results). Does anyone have suggestions of maybe some better settings for this sample type?
Some other things: We also have graphite furnace and flame AAs available for use if they'd handle this sample better. And we're also investigating ways to decompose the TBHP before analysis, but the ways we've come up with interfere with the elements we're looking for.
Any suggestions would be greatly appreciated. Replies here or offline are welcome.
Julia C. Spraul
Researcher, Analytical Services, Newtown Square
Lyondell Chemical Company
3801 West Chester Pike
Newtown Square, PA 19073
Office: +1 610.359.2357
Fax: +1 610.359.2442
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