Re: [ISOGEOCHEM] Question on nanotechology
A couple of questions for you John,
 
1)  What is your yield (atoms counted per atom sputtered) for O in these minerals?
 
2) Do you use just high mass resolution or is there a component of energy filtering in the analysis?
 
Thanks in advance,
 
John
 

John B. Cliff, Ph.D.
Research Scientist
Advanced Radioanalytical Chemistry Group
National Security Division
Pacific Northwest National Laboratory
Richland,  WA   U.S.A.
(509) 373-9003, fax (509) 376-5021
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From: Stable Isotope Geochemistry [mailto:[log in to unmask]] On Behalf Of John Valley
Sent: Tuesday, October 31, 2006 2:00 PM
To: [log in to unmask]
Subject: Re: [ISOGEOCHEM] Question on nanotechology

Pier and others

There is a physical limit on how small you can go with stable isotope analysis.  There must be enough atoms of the minor isotope for the desired precision. Furthermore, no analytical technique is 100% efficient.

With the new 1280, we get precision of ~0.1 permil for oxygen 18/16 on common minerals from a 10 micron spot, 1 micron deep. At 5 microns, the precision is a bit worse.  Our minimum spot is 250nm dia., but oxygen will not be good at that scale. Alternatively, we can expand the spot and depth profile at sub-micron levels.

There are some analyses for isotope ratios from spots as small as 100nm dia. by nanoSIMS, but the precision will never be good enough to be useful for stable isotope ratios in natural samples from Earth.  There are good applications in meteoritics, and for labelled experiments especially in biology.

Those are the two communities you might want to address.

John

Dear all,

I am wondering if there is activity on analyzing, or any other application of nanoparticles in the field of stable isotopes?
Since nanotechnology is very much in the spotlights nowadays (I wonder if that might be one of the targets in the 7th Framework Programme of the EU; programme still to be decided!!!) there might be interest for isotopic work too.

If anybody knows about such activity I very much like to learn about it.
Thanks in advance for your reaction(s).

Best wishes,
Pier.
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 John W. Valley,                        phone: 608-263-5659
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