Dear readers of the Plasmachem mailinglist,
We have difficulties with the determination of Sc on our PE Elan 5000 ICP-MS.
We use NIST 1547 Peach leaves as a reference. Certified value is 40ppb of Sc
in the dried substance. Our problem is that we find much more Sc than the
The same about peat samples. We get 2.5 times the value measured by XRF. Pb,
Ti and other elements give the correct values (certified and also compared
with the XRF values).
Stange thing is we get the correct values for Standards, so it has to be
something that's in the samples.
The digestion we use is as follows: 0.2g dried sample, 1ml conc Ultrapure
HNO3. Digestion in a microwave under a pressure of 60bar. Then 40Ál of HF
>is added and the sample diluted to 12ml (deionized water).
We analyzed the TOC left after the digestion and it's about 400-500ppm left.
Also the samples have high amounts of K, Na, Ca, Mg, Al, P, S.
Does anybody of you have an idea what may be the problem, or how to prevent
I appreciate any help or hints from you.
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