Carrier-free

Baumgartner and Reichold prepared carrier-free Mo(CO)g in high yield by neutron irradiation of powdered mixtures of UjOg and Cr(CO)g. As with their preparation of ° RuCp2, the Cr(CO)g acted only as a catcher for fission-product molybdenum (and for its precursors niobium and zirconium). The yield of 60% found for Mo(CO)6 is higher than the fractional chain yield of Mo in fission, so that the reaction must be partly thermal, starting with molecular fragments which survive j8 decay. 

Carrier-free species are apt to accompany other macrocomponents through the separation procedures, especially sublimation. 

Failure to measure chemical yields and to identify products are sometimes difficult to rectify, especially in the case of unexpected carrier-free compounds. Unfortunately, the amounts involved are so small that even the... 

Less clearly recognizable as scavenging, but in principle the same thing, is the evident reaction of glass surfaces with carrier-free species. While this phenomenon has been studied widely in radiochemistry, adsorption on the walls of glass vessels has been more of a nuisance to be avoided. Harbottle... 

The only respect in which the hot atom chemistry of organometallic compounds has so far been applied to other fields of study is in the area of isotope enrichment. Much of this has been done for isolation of radioactive nuclides from other radioactive species for the purpose of nuclear chemical study, or for the preparation of high specific activity radioactive tracers. Some examples of these applications have been given in Table II. The most serious difficulty with preparation of carrier-free tracers by this method is that of radiolysis of the target compound, which can be severe under conditions suited to commercial isotope production, so that the radiolysis products dilute the enriched isotopes. A balance can be struck in some cases, however, between high yield and high specific activity (19, 7J),... 

Deoxy-2-[ F]fluoro-D-mannose ( F-2DFM) was prepared through treatment of 201 (see Section 11,2) with F-Bu4NF(MeCN, 75°, 30 min) or K F crown ether, as reported for the cold synthesis. F-2DFM was also prepared from methyl 4,6-di-0-acetyl-3-C>-benzoyl-2-C>-triflyl-a-D-glu-copyranoside with amino(polyether)-supported, carrier-free [ F]fluoride. 

Domow et al. [201] have reported on the use of cyclotron-produced carrier-free and they obtained a narrower line width (53 pm s ) as compared to the procedure using neutron-activated activity. However, both procedures are... 

The two Mossbauer levels of Pt, 99 keV and 130 keV, are populated by either EC of Au(fi/2 = 183 days) or isomeric transition of Pt(fi/2 = 4.1 days). Only a few authors, e.g., [323, 324] reported on the use of Pt, which is produced by thermal neutron activation of " Pt via " Pt(n, y) Pt. The source used in the early measurements by Harris et al. [322, 325] was carrier-free Au diffused into platinum metal. Walcher [326] irradiated natural platinum metal with deuterons to obtain the parent nuclide Au by (d, xn) reactions. After the decay of short-lived isotopes, especially Au(fi/2 = 6.18 days), Au was extracted with ethyl acetate, and the Au/Pt source prepared by induction melting. Buym and Grodzins [323] made use of (a, xn) reactions when bombarding natural iridium with... 

Hjerten, S., Elenbring, K., Kilar, F., Liao, J.-L, Chen, A. J. C., Siebert, C. J., and Zhu, M.-D., Carrier-free zone electrophoresis, displacement electrophoresis and isoelectric focusing in a high-performance electrophoresis apparatus, /. Chromatogr., 403, 47, 1987. 

Seidel A, Wiener M, Kruger E, et al. 1986. Studies on the lysosomal binding of 141Ce, 239Np, 239Pu and 241 Am in rat and Syrian hamster liver using carrier-free electrophoresis. Int J Rad Appl Instrum B13(5) 515-518. 

Kahn, M., Coprecipitation, Deposition, and Radiocolloid Formation of Carrier-Free Tracers, Radioactivity applied to Chemistrv(A. C. Wahl, and N. A. Bonner, ed) pp. 403-433, John Wiley Sons, Inc., New York (1951). 

Veljkovic, S. R., and S. M. Milenkovic, Concentration of Carrier-free Radioisotopes by Adsorption on Alumina, in Proc. of the 2nd UN Conference on Peaceful Uses of Atomic Energy. Vol. 20, pp. 45-49, United Nations (1958). 

Table 18—Concentration of uCe in the tissues of adult mammals after injection of carrier-free MCeCl3 (pH = 3) b... 

Table 19—Deposition and concentration of, 44Ce in the tissues of adult mice and ratsk after injection of carrier-free, 44CeCl3...

Scott, K. G., Overstreet, R., Jacobson, L., Hamilton, J. G., Fisher, H., Crowley, J., Chaikoff, I. L., Entenman, C., Fishler, M., Barger, A. J. AND Loomis, F. (1947). The Metabolism of Carrier-Free Fission Products in the Rat, Report No. MDDC-1275 (National Technical Information Service, Springfield, Virginia). 

Add the desired number of beads to a solution of carrier-free Na125I in iodination buffer at a concentration level of about 1 mCi per 100 pg of protein to be modified. The total reaction volume should be 100-1,000 pi per bead. 

Add carrier-free Na125I to the reaction vessel in a ratio of about 500 piCi per 100 pig protein. 

Aromatic dehalogenation suffers from the disadvantage that only 50% of the tritium is incorporated, the rest appearing as waste. This situation is even more marked for borotritide reductions but the problem can be overcome by using some of the new tritide reagents that have recently become available as a result of the synthesis of carrier-free lithium tritide (Scheme 13.1) [22], Their reactivity can be fine-tuned through the elements (e. g. B, Al, Sn) to which the tritium is attached and by the electronic and steric nature of the substituents at the central atom. 

Imura and Suzuki36 have prepared labelled organotin compounds from artificial tin isotopes produced in a cyclotron. The carrier-free tin-113 radioisotope was produced by irradiating indium-115 oxide with 40-MeV protons (equation 33). 

Carrier-free radiochemical is a radionuclide that is not contaminated with a stable or radioactive nuclide of the same element. The no carrier added (NCA) designation applies to most of the elements to which the term carrier free is indicated. The specific activity of a carrier-free radioisotope can be calculated by the following formula ... 

What is the specific activity of carrier free 99mTc The tM of 99mTc is 6 hours. 

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