Papers by Branislava Tenjovic
Journal of Radioanalytical and Nuclear Chemistry, 2019
In a case of a nuclear emergency, rapid radiostrontium analysis in milk is essential, since milk ... more In a case of a nuclear emergency, rapid radiostrontium analysis in milk is essential, since milk ingestion poses a considerable risk for radiostrontium implantation in the human body especially in infants. The main idea of this study is to investigate a simple, fast and low-cost method for 90 Sr determination in milk samples, through microwave digestion followed by Cherenkov radiation detection on a Liquid Scintillation Counter Quantulus 1220™. Obtained results set method's limit on a screening test for emergency situations only (uncontrolled nuclear waste discharges/nuclear power plant accidents etc.), adequate for a quick reliable estimate of 90 Sr content.
Journal of Environmental Radioactivity
A procedure for the determination of 90Sr in environmental water samples using Čerenkov radiation... more A procedure for the determination of 90Sr in environmental water samples using Čerenkov radiation and low-level liquid scintillation counter Quantulus 1220 was applied and optimized. Low diffusion polyethylene vials, high performance glass counting vials and low potassium borosilicate glass vilas of 20 ml volume (all from PerkinElmer) were used in order to examine their potential effect on counting process. The derived efficiencies were 45.86(9)%, and a minimum detectable activity of 0.32 Bq l-1 in a 20 ml polyethylene vial (20 ml water sample) has been achieved during 300 min of measurement. Environmental water samples might be colored and this will lead to color quenching, which one of the most important problems that affect Čerenkov is counting (Mosqueda et al., 2005). The sample channel ratio (SCR) method has been applied to correct this effect. The analytical procedures and measurement techniques were tested by participating in the IAEA-TEL-2015-03 world-wide proficiency test on determination of 90Sr in water sample.
Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine, Jan 13, 2018
Monitoring of Rn in drinking or surface waters, as well as in groundwater has been performed regu... more Monitoring of Rn in drinking or surface waters, as well as in groundwater has been performed regularly in connection with geological, hydrogeological and hydrological surveys and health hazard studies. Liquid scintillation counting (LSC) is often preferred analytical method for Rn measurements in waters as it allows multiple-sample automatic analysis. LSC method implies mixing of water samples with organic scintillation cocktail, which triggers radon diffusion from the aqueous into an organic phase for which it has a much greater affinity, eliminating the possibility of radon emanation in that manner. The main aim of this paper is calibration of the liquid scintillation counter Qunatulus 1220™ for measuring of radon in water and evaluation of two different methods (one-phase and two-phase) in order to obtain the most suitable LSC technique for radon in water measurement. In this study four different scintillation cocktails were tested: one miscible (Ultima Gold AB) and three immisci...
Journal of Radioanalytical and Nuclear Chemistry, 2014
ABSTRACT Quench effects can cause a serious reduction in counting efficiency for a given sample/c... more ABSTRACT Quench effects can cause a serious reduction in counting efficiency for a given sample/cocktail mixture in liquid scintillation counting (LSC) experiments. This paper presents a simple experiment performed in order to test the influence of quenching on the LSC efficiency of 3H. The aim of this study was to investigate the behavior of several quench agents with different quench strengths (nitromethane, nitric acid, acetone, dimethyl-sulfoxide) added in different amounts to tritiated water in order to obtain standard sets for quench calibration curves. The OptiPhase HiSafe 2 and OptiPhase HiSafe 3 scintillation cocktails were used in this study in order to compare their quench resistance. Measurements were performed using a low-level LS counter (Wallac, Quantulus 1220).
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Papers by Branislava Tenjovic