On Friday, December 12, 2003 at 10:51:21 AM UTC-7, Inor wrote:
Hello,
I've been running ICP-OES for three years now. The Instrument is a PerkinElmer Optima 3000. It's about ten years old. We bought it used in 1995 or 96. I've been struggling with what seems to be an ever-worsening sensitivity/ low-end stability problems. Most notably, when I run a low-level (10 ppb) check on the lower wavelength elements, i.e As, Se, and Tl, I have a hell of a time getting them to pass. We've replaced mirrors, lenses, PA tube and the sample intro system is cleaned/replaced every three months or so. My question is, do these things eventually just wear out (it gets alot of use, environmental monitoring: soils and waters). Are there
any suggestions short of buying a new instrument (although I know some of
the new ones are capable of sub-ppb levels on some elements). Any help is greatly appreciated.
R. Lawrence
Paradigm Analytical Labs
High! I ran an Optima 3000 for a few years, but it was eventually replaced by a Varian. I liked the Optima, but the autosampler really sucks. Have you tried looking at the wavelength profile for the elements you're having problems with and examined the
background base line? I think this technique is very useful when your dealing with determining concentrations close to the LDL.
--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)