Results 161 to 170 of about 40,082 (212)
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1979
Carbon —14 and tritium are β− emitting radioisotopes with β− emissions of very low energy which are extremely difficult to detect with any form of window counter, due to self-absorption of the β− particles and their absorption within the counter window.
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Carbon —14 and tritium are β− emitting radioisotopes with β− emissions of very low energy which are extremely difficult to detect with any form of window counter, due to self-absorption of the β− particles and their absorption within the counter window.
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Liquid scintillation counting in nuclear medicine
Seminars in Nuclear Medicine, 1973Many of the radionuclides used in nuclear medicine can be measured by liquid scintillation (LS) counting, and the technique is the only practical approach to counting low-energy β emissions. This review is intended to be a brief exposition of the capabilities of LS counting and of some precautions that should be observed.
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Counting Statistics for Liquid Scintillation Counting
Analytical Chemistry, 1961The way in which the errors associated with individual countings of a sample by liquid scintillation techniques are compounded in the calculation of a net disintegration rate was investigated. The standard deviation of rates calculated from duplicate samples is compared with the standard deviation calculated from a propagation of error equation. At the
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Liquid scintillation counting of porphyrins
The International Journal of Applied Radiation and Isotopes, 1985Abstract Carbon-14-labelled porphyrins may be counted by liquid scintillation up to a vial concentration of ca. 3 × 10−5 M (ca. 0.5 mg/vial), either directly or after initial sorption onto chromatography paper. A readily-constructed quench curve permits direct conversion of cpm to Bq and is pratical for 14C to ca. 35% efficiency.
Sam Aronoff +2 more
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Liquid Scintillation Counting of Tritium in Urine
Physics in Medicine and Biology, 1961An instrument is described using a single cooled photomultiplier for routine analysis of tritium in urine. The quenching effects and luminescence of urine treated by various methods are determined. For urine treated with activated charcoal the average activity required to double the background counting rate is 2 nanocuries per ml with an efficiency of ...
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Liquid scintillation counting of chlorophyll
The International Journal of Applied Radiation and Isotopes, 1975Abstract A precise and reproducible method of liquid scintillation counting was worked out for measuring the radioactivity of 14 C-labelled chlorophyll a and chlorophyll b solutions without previous bleaching. The spurious count rate caused by luminescence of the scintillant-chlorophyll system is eliminated by using a suitable scintillant and by
F. Frič +2 more
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Phosphorescence in Liquid Scintillation Counting of Proteins
Science, 1958In the investigation of alcoholic solutions of the quaternary base Hyamine for the counting of proteins and tissues, a phosphorescence phenomenon was encountered when working with larger weights of the substances. The protein- Hyamine solutions were usually heated between 50 and 70 d C for periods ranging from 1/2 hr to several hours.
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Quenching Correction in Liquid Scintillation Counting
1966Two types of quenching are encountered in liquid scintillation counting, chemical and color quenching. Chemical quenching is caused by the presence of nonfluorescent molecules in the liquid scintillator system which interfere with the energy transfer between the solvent and the organic scintillator.
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Liquid scintillation counting of H2S35
The International Journal of Applied Radiation and Isotopes, 1961The cap of a Packard sample vial was modifiod to permit ready injection of the gas and yet prevent leakage. A series of such vials containing increasing volumes of Hsub 2/S/sup 35/ was countod after various periods to determine the linearity of the calibration curve (a measure of both quenching and loss of gas to the vapor space) and the change of the ...
B.E. Gordon, H.R. Lukens, W. ten Hove
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Simplified liquid scintillation counting
Physics in Medicine & Biology, 1971openaire +2 more sources