Titanium isotope

Hashimoto A, Hinton RW, Davis AM, Grossman L, Mayeda TK, Clayton RN (1986) A hibonite-rich Murchison inclusion with anomalous oxygen isotopic composition. Lunar Planet Sci XVII 317-318 Heydegger HR, Foster JJ, Compston W (1979) Evidence of a new isotopic anomaly from titanium isotopic ratios in meteoritic material. Nature 278 704-707... 

Hoppe P, Amari S, Zinner E, Ireland T, Lewis RS (1994) Carbon, nitrogen, magnesium, silicon and titanium isotopic compositions of single interstellar silicon carbide grains from the Murchison carbonaceous chondrite. Astrophys J 430 870-890... 

Weber D, Zinner E, Bischoff A (1995) Trace element abundances and magnesium, calcium, and titanium isotopic compositions of grossite-containing inclusions from the carbonaceous chondrite Acfer 182. Geochim Cosmochim Acta 59 803-823... 

Titanium isotopic data for mainstream silicon carbide grains versus 829Si. The correlation between excesses of minor titanium isotopes and minor silicon isotopes most likely reflects galactic chemical evolution. The offset of the S50Ti trend to pass above the solar composition probably reflects 5-process nucleosynthesis in the parent stars, which most strongly affects 50Ti. Data from Huss and Smith (2007) and references therein. 

Huss, G. R. and Smith, J. A. (2007) Titanium isotopes in isotopically characterized silicon carbide grains from the Orgueil Cl chondrite. Meteoritics and Planetary Science, 42, 1055-1075. 

The light nuclei through the titanium isotopes. Black squares indicate stable nuclei shaded squares indicate nuclei whose masses have been precisely measured and white squares indicate nuclei whose existence has been verified experimentally. Nuclei such as 8C and 19Na, which are known to be nucleon unstable, are shaded but not included in a framed square. 

From the isotopic decomposition of normal titanium one finds that the mass-46 isotope, 4STi, is one of the four lesser abundant of the stable titanium isotopes 8.0% of all Ti. On the scale where one million silicon atoms is taken as the standard for solar-system matter, this isotope has... 

Alexander, 1993 Hoppe et al., 1997). Comparison of the carbon, silicon, and titanium isotopic ratios of Y grains with models of nucleosynthesis indicates an origin in low-to-intermediate-mass AGB stars with approximately half the solar metallicity (Amari et al., 2001b). Such stars dredge up more and silicon and titanium that... 

Clayton D. D., ObradovicM., Guha S., and Brown L. E. (1991) Silicon and titanium isotopes in SiC from AGB stars. In Lunar Planet. Sci. XXII. The Lunar and Planetary Institute, Houston (CD-ROM), pp. 221—222. 

Figure 16 °Ti isotopic composition versus calculated initial Al/ Al for hibonite-bearing CAIs from CM chondrites. Titanium isotope anomalies larger than 10%o do not occur in CAIs with initial Al/ Al 5 X 10 , and vice versa. Diagram is updated from Clayton et aL (1988, figure 7). Only analyses having Al/Mg > 20 are shown (sources Fahey etaL, 1987a Hinton etaL, 1984 Hutcheon etaL, 1980 Ireland, 1988, 1990 Ireland and Compston, 1987 ...

There are other refractory inclusions, e.g., grossite-bearing CAIs from CH chondrites (Weber et aL, 1995), that do not fit this model since they lack calcium and titanium isotopic anomalies as well as Al. One interpretation of such objects could be that CAI formation lasted several million years, but this is not supported by any independent evidence and there could well be other reasons for the lack of both short-lived radioactivity and large isotopic anomalies (aside from excesses Sahijpal et al., 1999) in these inclusions. Circumstantial arguments against a long time period for CAI formation are that it... 

Ireland T. R., Compston W., and Heydegger H. R. (1985) Titanium isotopic anomalies in hibonites from the Murchison carbonaceous chondrite. Geochim. Cosmochim. Acta 49, 1989-1993. 

For most other elements there is no difference between the isotopic composition of carbonaceous chondrites and the Earth. As of early 2000s, only two exceptions, chromium and titanium, are known for these two elements very small differences in the isotopic composition between carbonaceous chondrites and the Earth were found. Bulk carbonaceous chondrites have isotope anomalies in chromium and titanium. Isotopically unusual material may have been mixed to the CC-source after proto-earth material has accumulated to larger objects. 

Other problems may be caused by the matrix of the sample itself. If chloride is present, a series of polyatomic chloride-containing species may cause major interferences. As an example, Ar CT is an intense peak that interferes with As". Arsenic is monoisotopic therefore appreciable levels of chloride in the sample will seriously compromise the precise determination of arsenic. Components of the sample matrix may also contribute to oxide formation. Oxides of the form MO give rise to peaks at the (M/Z)+16 position. One or more of these may interfere with nuclides of interest. An example of this is Ti 0 interfering with the analysis of Zn. The four other naturally occurring titanium isotopes would, of course, also give interference at their respective (M/Z)-i-16 values to any analytes with these masses. Formation of the oxide of the analyte also reduces the signal measured at M/Z. 

The atomic weight of titanium is 47.88 (lUPAC 1971 based on C = 12.000) and was originally determined by the ratio TiCU/4Ag and TiBr4/4Ag. Slight separation of the titanium isotopes is possible in the extraction of thiocyanic acid complexes of titanium by ether from aqueous sulfate solutions. The separation factors are Ti Ti = 1.006, Ti Ti = 1.008 and Ti Ti = 1.014,... 

Titanium isotopes and the radial heterogeneity of the solar system. Earth Planet. Sd. Lett., 266, 233-244. 

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