Hi Michael,
The isotope fractionation (of S and O) between SO4= (ion) and CaSO4 (ion pair)
indeed exist in concentrate solutions. We can evaluate it at equilibrium
conditions by subtracting from CaSO4(crystalline)--SO4= equilibrium
fractionation the contribution of the acoustic contribution to the reduced
partition function ratio. This seems to be a small correction, perhaps
lower than analytical uncertainty by CFIRMS :)
Regards, Stan
At 20:22 07-05-22 +0200, you wrote:
>Dear Pier,
>
>if you are interested in isotope fractionation between ion pairs/complexes
>and their corresponding free ions (e.g., CaSO4° versus SO42-) this is
>clearly a very interesting topic. Especially in disequilibrium systems,
>were reaction kinetics can become important. Although some systems can be
>followed by experimental approaches we are in need for theoretical
>predictions.
>
>
> >>> Dear all,
> >>>
> >>> I like to hear from you about interest on the topic of isotopic
> >>> speciation
> >>> in relation to isotopic analysis. Below are given some definitions on
> >>> 'speciation'.
> >>> Isotopic speciation in analysis is, what I think, a very much neglected
> >>> subject, where only few studies bother about
> >>> 'homogeneity/heterogeneity'
> >>> (basically a speciation problem) considering the sample-size used for
> >>> analysis.
> >>> I like to give it more attention and propose to have a session on this
> >>> subject for the next EGU meeting in 2008. A tentative session-title may
> >>> be:
> >>> 'Isotopic distribution in samples (speciation) in isotopic analysis'
> >>> (isotope includes here stable and radiogenic isotopes).
> >>>
> >>> Please, I like to get your reactions on my proposal. Any comment,
> >>> suggestion, or proposal is very welcome.
> >>>
> >>> I look forward for some discussion here....
> >>>
> >>> Best wishes,
> >>> Pier.
> >>>
> >>> ************
> >>> For those less introduced in this subject [from: EVISA web-site:
> >>> http://www.speciation.net/Public/Document/2003/09/11/495.html;
> >>> EVISA = European Virtual Institute of Speciation Analysis]:
> >>> Speciation as a discipline in Analytical Chemistry Definitions
> >>>
> >>> The International Union for Pure and Applied Chemistry (IUPAC) has
> >>> published
> >>> guidelines or recommendations for the definition of speciation
> >>> analysis:
> >>> Speciation analysis is the analytical activity of identifying and/or
> >>> measuring the quantities of one or more individual chemical species in
> >>> a
> >>> sample.
> >>>
> >>> The chemical species are specific forms of an element defined as to
> >>> isotopic
> >>> composition, electronic or oxidation state, and/or complex or molecular
> >>> structure.
> >>>
> >>> The speciation of an element is the distribution of an element amongst
> >>> defined chemical species in a system.
> >>>
> >>> In case that it is not possible to determine the concentration of the
> >>> different individual chemical species that sum up the total
> >>> concentration of
> >>> an element in a given matrix, that means it is impossible to determine
> >>> the
> >>> speciation, it is a usefull practice to do fractionation instead.
> >>>
> >>> Fractionation is the process of classification of an analyte or a group
> >>> of
> >>> analytes from a certain sample according to physical (e.g. size,
> >>> solubility)
> >>> or chemical (e.g. bonding, reactivity) properties.
> >>>
> >>> Further reading:
> >>> D.M. Templeton, F. Ariese, R. Cornelis, L.-G. Danielsson, H. Muntau,
> >>> H.P.
> >>> van Leeuwen, R. Lobinski, IUPAC Guidelines for Terms Related to
> >>> Speciation
> >>> of Trace Elements, Pure Appl. Chem., 72/8 (2000) 1453-1470.
> >>>
> >>> **********
> >>> Dr. Pier A. de Groot
> >>> Address for the period April 1, 2007 July 31, 2007:
> >>> Silesian University of Technology
> >>> GADAM Centre of Excellence
> >>> Institute of Physics Department of Radioisotopes
> >>> Krzywoustego 2, 44 100 Gliwice, Poland
> >>> Email: [log in to unmask]
> >>>
> >>> Permanent address:
> >>> Delta Isotopes Consultancy
> >>> Pastoor Moorkensstraat 16
> >>> 2400 Mol - Achterbos
> >>> Belgium
> >>> Tel. +32 (0)14 326 205
> >>> e-mail: [log in to unmask] or [log in to unmask]
> >>>
> >>> Associate editor for stable isotopes of eEarth on-line magazine
> >>> http://www.electronic-earth.net
> >>>
> >>> Head of Isotopes in Geosciences of the European Geoscience Union (EGU).
> >>> EGU Home web-site: http://www.copernicus.org/EGU/EGU.html
> >>>
> >>> Organization Committee member of BASIS (Benelux Association of Stable
> >>> Isotope Scientists).
> >>> http://www.basis-online.eu/
> >>>
> >>> Visit my WEB-site about my ³Handbook of Stable Isotope Analytical
> >>> Techniques², with a link to the Elsevier web site on the handbook
> >>> (marked:
> >>> ŒOrder Now¹):
> >>> http://users.pandora.be/handbook/index.html
> >>> last update: August 15, 2005
> >>> Volume I is now available. Volume II is expected to be available in
> >>> 2007.
> >>>
> >>> ****************************************************************
> >>
> >> Dr. Stanislaw Halas
> >> Mass Spectrometry Laboratory
> >> Institute of Physics, UMCS
> >> 20-031 Lublin, Poland
> >> phone: +48 81 537-62-75
> >> fax: +48 81 533-36-69
> >>
> >
> > --
> > Pier de Groot
> > Silesian University of Technology, Institute of Physics
> > Department of Radioisotopes, GADAM Centre of Excellence
> > Krzywoustego 2, 44-100 Gliwice, POLAND
> > tel. +48 32 237 2662, fax. +48 32 237 2254
> > E-mail: [log in to unmask]
> > http://www.carbon14.pl/
> >
Dr. Stanislaw Halas
Mass Spectrometry Laboratory
Institute of Physics, UMCS
20-031 Lublin, Poland
phone: +48 81 537-62-75
fax: +48 81 533-36-69
|
