Beta-particle emitters

FIGURE 7.11 Schematic for radiochemical detection of analytes labeled with beta-particle emitters. Radio-labeled analytes in the column effluent are mixed with scintillation cocktail to produce light, which is detected and measured by the paired photomultiplier tubes and relayed to a data acquisition system. 

Curves for this equation have been obtained by measuring various beta-particle emitters in several geometric arrangements of source and detector. One of the empirical relations found between p and the maximum beta-particle energy, E, in MeV, is shown by Equation 4.2 ... 

Radionuclides (alpha particle emitters, beta particle emitters, radium-226, and uranium)... 

Preparation of purified samples for alpha-particle spectrometry is usually by either electrodeposition or micro-coprecipitation. Either technique takes at least an hour. Many beta-particle emitters are precipitated with several milligrams of carrier and weighted for determining the chemical yield prior to counting, which also takes time. In contrast, a few millilitres of solution are satisfactory for ICP-MS. If the analyte concentration should exceed the linear part of the calibration curve, a simple dilution overcomes the problem. 

Cross-fire effect from beta particle emitters 500 Cryptococcus neoformans 686 Cryptotope 1191 cTnl 290... 

Sodium-24 is a beta-particle emitter with a half-life of 14.8 hours. Calculate the activity in curies of a 20-mg sample of NaCl enriched with Na so that it contains 1 atomic percent of Na. (1 curie = 3.70 x 10 dps.)... 

Older LS counter systems (see Section 8.3.2) have three channels for distinguishing energies new ones have full energy spectrometers. These are directly applicable for distinguishing alpha particles by energy. Because beta particles are emitted as a spectrum from zero to maximum energy, and the spectra have various shapes, identification of beta-particle emitters by energy is less feasible. 

Alpha-particle counting is the most commonly used method for determining plutonium concentrations at low levels in biological samples, as well as in process waste streams, and in soil, water, and air filter samples (Brouns 1980). This method does not distinguish between the different alpha-particle emitters of plutonium (plutonium-236, plutonium-238, plutonium-239, plutonium-240, plutonium- 242), nor does it detect plutonium-241, a beta-particle emitter. 

Quantities of plutonium-241, a beta-particle emitter, can be quantified from (1) assumed isotopic abundance ratios, (2) estimated in-growth of its progeny americion-241 by gamma spectrometry, or by (3) mass spectrometry (Bernhardt 1976). Americium-241 is produced from the beta decay of plutonium-241 and, therefore, can be used to indirectly measure the concentration of plutonium-241 (Metz and Waterbury 1962). Direct determination of plutonium-241 by measurement of its low energy beta-particle decay has been reported using liquid scintillation analysis (Martin 1986). 

For radionuclides of 9 of the elements in Figure 1, direct activity measurements were made in which the disintegration rate of the radionuclide is determined directly for each vial (NCRP, 1978). For accurate direct measurements of beta-particle emitters, the beta-particle counting efficiency must be as high as possible, and, consequently, scintillators that exhibit... 

For comparative assays of beta-particle emitters, such as and Ni, vials prepared from a standard solution of the radionuclide are compared to those prepared from an unknown solution. It is not essential that the scintillation yield be exceptionally high for such comparative measurements it is more important that the chemical compositions of the two solutions be the same, so that the type and degree of quenching will be the same for both unknown and standards vials. 

Most of our work with transition metal radionuclides has been with Fe and Ni. The former decays by electron capture, for which the highest energy x-ray is 5.5 keV (Gibson and Marshall, 1972). The Ni is a low-energy beta-particle emitter (Eg maximum of 55.87 keV). To prepare very high-efficiency scintillators for these two radionuclides, one... 

In this study, we have extended these results to include S. In addition, we have presented methods utilizing fluorography by which proteins labeled with weak beta-particle emitters such as H, can be used to produce autoradiograms and then analyzed by liquid scintillation spectrometry. 

A beta particle is essentially an electron that s emitted from the nucleus. (Now 1 know what you re thinking — electrons aren t in the nucleus. Keep on reading to find out how they can be formed in this nuclear reaction.) Iodine-131 (1-131), which is used in the detection and treatment of thyroid cancer, is a beta particle emitter ... 

Tritium (IP or T) is a radioactive hydrogen isotope of mass 3. It is a very low-level, negative beta particle emitter (< 0.02 m.e.v.) w ith a half life of about twelve years. The lability of the isotope in the C— 1 bond is less than in the C—D bond, w hich in turn is less than in the C- -H bond. ... 

P is a negative beta particle emitter (1.7 m.e.v.) with a half life of 14.3 days. It has been used extensively in the study of phospholipide metabolism. The rapid appearance of labeled phospholipides in the animal after the administration of phosphate-P constitutes evidence that phospholipides are synthesized in the animal body. ... 

Rubidium-87, a beta particle emitter, is the product of positron emission. Identify... 

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