Radionuclide tracer

Pfutzner, W. et al.. Intraoperative labeling of sentinel lymph nodes with a combination of vital dye and radionuclide tracer results in sentinel lymph node-positive patients, J. Deutsch. Dermatol. Ges., 4, 229, 2006. 

Moore WS, Demaster DJ, Smoak JM, McKee BA, Swarzenski PW (1996) Radionuclide tracers of sediment-water interactions on the Amazon shelf. Cont Shelf Res 16 645-665 Moran SB, Moore RM (1989) The distribution of colloidal aluminum and organic carbon in coastal and open ocean waters offNova Scotia. Geochim Cosmochim Acta 53 2519-2527 Nozaki Y (1991) The systematics and kinetics of U/Th decay series nuchdes in ocean water. Rev Aquatic Sci 4 75-105... 

The extent and rate of removal of radionuclide tracers from sea water can be ascertained through a knowledge of their residence time in the water column. The residence time, t, of a tracer due to its physical removal from one reservoir to another is defined [37,38,39,40,41] as ... 

Fig. 8. Radionuclide migration studied in a granitic shear zone at the Grimsel test site, Switzerland (injection flow rate 10 mL/min extraction flow rate 150 mL/min, dipole distance 2.3 m). Am(III), Pu(IV) and Th(IV) are co-eluted with the colloids grey vertical lines indicate maxima of breakthrough curves (Geckeis et al. 2003). In order to allow a direct comparison of breakthrough curves, the colloid and radionuclide concentrations (c in mg/mL) in the extracted water samples are normalized to the total injected mass of individual colloid or radionuclide tracers (mn in mg).

As indicated above, frequently the amount of material involved in a radiochemical procedure is quite small. To obviate some of the difficulties associated with this, a weighable amount ( mg) of inactive material, the carrier, is added to the procedure at an early stage. It is essential that this carrier and the radionuclide (tracer) be in the same chemical form. This is achieved usually by subjecting the carrier + tracer system to one or more redox cycles prior to initiating any chemical separations to ensure that the carrier and tracers are in the same oxidation state. 

M. F. L Annunziata, Radionuclide tracers their detection and measurement, Academic Press, London, 1987, ISBN 0124362524. 

Moore, W. S., D. J. DeMaster, J. M. Smoak, B. A. McKee, and P. W. Swarzenski. 1996. "Radionuclide tracers of sediment-water interaction on the Amazon shelf." Continental Shelf Research 16 645-666. 

Recognizing that scavenging of dissolved radionuclide tracers is a reversible process was a milestone in understanding the removal of particle-reactive substances from the ocean. This principle must be taken into account in using natural radionuclides as tracers of particle transport, and when using natural radionuclides to infer the rates of processes responsible for scavenging particle-reactive substances (e.g., trace metals) from the ocean. 

Kersten, M., Leipe, T., Tauber, F., 2005. Storm disturbance of sediment contaminants at a hot-spot in the Baltic Sea assessed by 234Th radionuclide tracer profiles. Environmental Science and Technology, 39, 984—990. 

Livingston HD, Swift JH, and Ostlund HG (1985) Artificial radionuclide tracer supply to the Denmark Strait Overflow between 1972 and 1981. Journal of Geophysical Research 90 6971-6982. 

The low concentration of radionuclides has stimulated near-universal application of an isotope dilution technique ( reverse isotope dilution ) that permits measurement of chemical recovery, termed yield. As commonly applied outside the radioanalytical chemistry laboratory, isotope dilution consists of the addition of a known amount of radionuclide tracer to a sample that contains its stable element, i.e., the natural mixture of stable isotopes of the element. The tracer is added at the beginning of the procedure and then measured in the separated and purified sample. If the added tracer and the stable isotopes of interest are assured at the beginning to be in the same chemical and physical form, then the fraction of recovered tracer represents the fraction of recovered stable isotope. 

Isotope dilution begins with the addition of a known amount of calibrated radioactive tracer solution R[ to a sample of mass nii in solution. By measuring the mass recovered mi and the radionuclide amount at the end of the procedure, Ri, one calculates the initial mass. Designating Si and as the specific activity (i.e., the ratio of radionuclide amount to the mass of the same element, at the beginning and end, respectively) and OTri as the mass associated with the radionuclide tracer initially gives the following relationships ... 

For the purpose of radiochemical analysis, one uses reverse isotope dilution by adding a known mass of stable carrier solution to the radionuclide sample solution, instead of adding a radionuclide tracer to the stable element. The mathematical expression is identical to Eq. (4.5) ... 

UAnnunziata MF (1987) Radionuclide Tracers Their Detection and Measurement. New York Academic Press. 

The application of radionuclide techniques in studying water movement in oceans, streams, and lakes is considered in the references cited in Section 7.1. In addition, Ellis (1967) prepared a review of the literature relevant to stream gauging with radionuclide methods. The study of water movement includes techniques that utilize fallout radionuclides, radionuclides released during operation of a nuclear facility, and direct introduction of a radionuclide by the investigator. In reference to the sea, Duursma (1972) tabulated some investigations of water movement using radionuclide tracers (Table 12). 

Figure 42. Detenniiiation of Columbia River flow tunes using radionuclide tracers released by the Hanford reactors, (a) Site map of Columbia River from Priest Rapids to mouth, (b) in Columbia River samples from six locations. From J. L. Nelson et al. (1966).

Research on physiological processes of aquatic higher plants using a radionuclide tracer is unknown to us. If such research has been conducted, we are reasonably sure that it is not common. 

Figuie 62. Hddiiig pen used in a study that utilized radionuclide tracers of the metaboUsm of phosphorus and iodine in dew. Ftom Rerabek and Bubenik (1963). 

We have selected a sample of the many papers utilizing radionuclide-tracer investigations of the food web that have appeared in the literature. As before. 

In a short but interesting paper, Wiegert and Odum (1969) discussed the use of radiotracer measurements in studies of food web diversity and utilized the data from the study discussed above (Wiegert et aL, 1967). They stated We feel that radionuclide tracers can simultaneously serve to identify the actual, as opposed to the merely possible trophic interactions, and tell us something about the quantitative importance of a given pathway. ... 

Radionuclide-tracer studies in natural marine environments obviously must rely on natural radioactivity in the environment or on radionuclides introduced from the activities of man such as fallout from nuclear-weapons testing or release of major amounts of nuclear waste such as from the Hanford Operations via the Columbia River. Some studies of this type have been discussed. We will conclude this section with those that are more closely related to investigations of com-plete ecosystems or subsystems. 

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