Cations partitioning

Ulmer, P. (1989). The dependence of the Fe2+-Mg cation-partitioning between olivine and basaltic liquid on pressure, temperature and composition An experimental study to 30kbars. Contrib. Mineral. Petrol., 101, 261-73. 

The prediction that site symmetry in magmas influences cation partitioning (Bums and Fyfe, 1964) was borne out by subsequent experimental investigations involving Ni2+ (e.g., Irvine and Kushiro, 1976) and Cr3+ (Irvine, 1974, 1975 Barnes, 1986) which are described later ( 8.5.5 and 8.5.6). 

Philpotts, J. A., Schnetzler, C. C. Large Trace Cation Partitioning in Igneous Processes. 

Figure 4 Brice model fits to 1+, 2+, and 3+ cation partitioning between plagioclase (Ang9) and silicate melt in the system diopside-albite-anorthite (Blundy and Wood, 1994). Note that the best-fit curve becomes tighter as the charge on the cation increases from 1 + through 3+. This is due to increase in effective Young s modulus of the site with increasing charge (see text).

Figure 8 Plot of bulk modulus versus cation charge (Zc) divided by metal-oxygen distance cubed (A ) for cation polyhedra in oxides (Hazen and Finger, 1979) and for 1-h, 2-h, and 3-h ions in the M2-site of clinopyroxene (Wood and Blundy, 1997) and the cation site in plagioclase (Blundy and Wood, 1994). Note that the linear correlation derived from compressibility data by Hazen and Finger holds reasonably well in our results independently estimated from the -dependence of cation partition coefficient.

P-T conditions are ordinarily calculated based on the T-dependence of a cation partitioning equilibrium (e.g., Fe-Mg exchange between garnet and biotite), and the F-dependence of a net-transfer equilibrium (e.g., anorthite = grossular + aluminosilicate -h quartz). Most barometers have moderate slopes, so the calculated P depends moderately on T. The basic problem... 

Artioli, G., Rinaldi, R., Wilson, C.C., Zanazzi, P.F. (1995). High temperatnre Fe-Mg cation partitioning in olivine In situ single-crystal neutron diffraction study. Am Minei 80 197-200... 

Loux, N. T D. S. Brown, C. R. Chapin, J, D. Allison, and S. M. Hassan. 1989. Chemical speciation and competitive cationic partitioning on a sandy aquifer material. J. Chem. Speciation Bioavailability 1 111-25. 

Mesto, E., Schingaro, E., Scordari, F, Ottolini, L. (2006) Electron probe microanalysis, secondary ion mass spectrometry and single crystal X-ray diffraction study of phlogopites from Mt. vulture, Potenza, Italy consideration of cation partitioning. Am. Mineral, 91,182-190. 

Cruciani, G., Zanazzi, P.F. (1994) Cation partitioning and substitution mechanism in IM phlogopite a crystal chemical study. Am. Mineral, 79,289-301. 

Several methods, other than the partition coefficient, have been developed to assess the hpophilicity of ILs. In a recent paper, Stepnowski and Storoniak [5] used reversed phase chromatography to obtain information on cation partitioning (regardless of the identity of the anion), in order to simulate what happens when ILs enter an aquatic environment. All the ILs investigated showed a preferential partitioning into the aqueous phase. It is worth noting that, even if this behaviour may account for the fate of weU solvated dissociated cations, it does not take into account possible interactions with biological membranes. 

Fig. 20.36 The equilibrium concentrations of mobile univalent anions and cations partitioned from the...

It is also important that RTlLs can generally withstand a- and y-radiation (Murding Tang, 2010 Allen et al, 2002), although in some cases irradiation of RTTL and of a chelating agent can diminish the radioactive cation partitioning (Chao et al, 2010). 

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