Natural and artificial (90Sr) radionuclides in some carbonated mineral waters used in Serbia

A radiological characterization of 7 different carbonated mineral water samples collected in the local supermarkets in the area of Belgrade (produced in Serbia) was carried out. Analysis included determination of gross alpha and gross beta activities. The obtained results showed that the natural activity concentrations of alpha and beta emitting radionuclides in carbonated mineral water samples were within World Health Organization recommended levels, except for the Heba Strong and Kiseljak samples where the beta activity exceeds 1 Bq/L. For these two water samples gamma spectrometry analysis was performed as well as determination of 90Sr by oxalic method. The instrumentation used to count the gross alpha and gross beta activities, as well as for 90Sr, was a/b low level proportional counter Thermo Eberline FHT 770 T. Gamma spectrometric measurements were performed using a HPGe Canberra detector with a counting efficiency of 20%. The annual effective dose equivalent due to ingestion of investigated waters was calculated for age group >17, and obtained values are lower than 0.1 mSv recommended reference level. Finally, a comparison of the investigated waters with worldwide data was made. [Projekat Ministarstva nauke Republike Srbije, br. III43009

Pulse perturbation technique for determination of piroxicam in pharmaceuticals using an oscillatory reaction system

A simple and reliable novel kinetic method for the determination of piroxicam (PX) was proposed and validated. For quantitative determination of PX, the Bray-Liebhafsky (BL) oscillatory reaction was used in a stable non-equilibrium stationary state close to the bifurcation point. Under the optimized reaction conditions (T = 55.0A degrees C, [H2SO4](0) = 7.60x10(-2) mol L-1, [KIO3](0) = 5.90x10(-2) mol L-1, [H2O2](0) = 1.50x10(-1) mol L-1 and j (0) = 2.95x10(-2) min(-1)), the linear relationship between maximal potential shift Delta E (m) , and PX concentration was obtained in the concentration range 11.2-480.5 A mu g mL(-1) with a detection limit of 9.9 A mu g mL(-1). The method had a rather good sample throughput of 25 samples h(-1) with a precision RSD = 4.7% as well as recoveries RCV a parts per thousand currency sign 104.4%. Applicability of the proposed method to the direct determination of piroxicam in different pharmaceutical formulations (tablets, ampoules and gel) was demonstrated

Radioaktivnost u životnoj sredini južne Srbije na lokacijama na kojima je korišten osiromašeni uran

In the 1999 bombing of the Federal Republic of Yugoslavia, NATO forces used ammunition containing depleted uranium. The cleaning of depleted uranium that followed was performed in southern Serbia by the Vinča Institute of Nuclear Sciences between 2002 and 2007 at the locations of Pljačkovica, Borovac, Bratoselce, and Reljan. This paper presents detailed results of radioactivity monitoring four years after cleaning (2011), which included the determination of gamma emitters in soil, water, and plant samples, as well as gross alpha and beta activities in water samples. The gamma spectrometry results showed the presence of natural radionuclides 226Ra, 232Th, 40K, 235U, 238U, and the produced radionuclide 137Cs (from the Chernobyl accident). In order to evaluate the radiological hazard from soil, the radium equivalent activity, the gamma dose rate, the external hazard index, and the annual effective dose were calculated. Considering that a significant number of people inhabit the studied locations, the periodical monitoring of radionuclide content is vital.U napadu na Saveznu Republiku Jugoslaviju 1999. godine NATO-ove su snage koristile municiju s osiromašenim uranom. Od 2002. do 2007. Laboratorij za zaštitu od zračenja i zaštitu životne sredine Instituta Vinča proveo je akciju čišćenja osiromašenog urana na lokacijama Pljačkovica, Borovac, Bratoselce i Reljan. U ovom se radu iznose detaljni rezultati praćenja radioaktivnosti u južnoj Srbiji četiri godine nakon spomenute akcije čišćenja (2011), koji uključuje određivanje gama zračenja u uzorcima zemljišta, vode i biljki te određivanje ukupne alfa i beta aktivnosti u uzorcima vode. Rezultati gama spektrometrije pokazali su prisutnost prirodnih radionuklida: 226Ra, 232Th, 40K, 235U, 238U i proizvedenog radionuklida 137Cs. Za procjenu radijacijskog rizika iz zemljišta izračunati su ekvivalent radija, brzina apsorbirane doze gama zračenja, indeks radijacijskog rizika uslijed vanjskog izlaganja i efektivna doza zračenja. Imajući u vidu da na ispitivanim područjima živi znatan broj ljudi, iznimno je važno da se ondje periodično prati sadržaj radionuklida

Perturbations of the Dushman Reaction with Piroxicam: Experimental and Model Calculations

Perturbation of the BrayLiebhafsky non-oscillating subsystem (mixture of KIO3 and H2SO4), i.e., Dushman reaction (DR), by piroxicam (PX), was observed in an open reactor, i.e., in the continuously fed well-stirred tank reactor (CSTR). Monitoring the response of DR to perturbations by different concentrations of PX allows developing a simple procedure for quantitative determination of this analyte in both bulk drug and pharmaceutical preparation (injection). A tentative perturbation mechanism of PX action on the DR matrix, based on a kinetic scheme that was suggested by Agreda etal., is proposed. The PX reactivity in DR has been generally related to the reaction of PX with hypoiodous acid (HIO) present in the matrix

Assessment of radioactivity contribution and transfer characteristics of natural radionuclides in agroecosystem

Taking into account the importance of distribution and transfer of radionuclides in the soil–plant system, especially in agricultural fields, the aim of this research was assessment of radioactivity contribution and transfer characteristics of natural radionuclides in agroecosystem. The measurement of the natural radioactivity distribution was conducted in organic and sustainable farming management systems. Statistical evaluation of the physical and chemical properties of soils subjected to different farming systems, revealed the existence of differences in some parameters. Balanced distribution of natural radionuclides in soil-crop system was observed. Radionuclide 40K was the most accessible to the investigated crops via uptake from the soil, then 232Th and 226Ra. The obtained results are useful for understanding the behavior of the radionuclides and provide an insight into the cumulative deposition of radioactivity in the agroecosystem

Temporal changes of beryllium-7 and lead-210 in ground level air in Serbia

7Be, 210Pb and 137Cs activity concentrations in ground level air at five monitoring stations (MS Vinča, Zeleno Brdo, Zaječar, Vranje and Zlatibor) in Serbia were determined during the period from May 2011. to September 2012., as part of the project monitoring of Serbia. Activity of the radionuclides in air was determined on an HPGe detector (Canberra, relative efficiency 20 %) by standard gamma spectrometry. Concentrations of cosmogenic 7Be, ranged from 1.5 to 8.8 mBq m-3 and exhibit maxima in the spring/summer period. The maximum concentrations for 210Pb were generally obtained in the fall for all investigated locations, and concentrations were in range 3.6 - 30 × 10-4 Bq m-3. The activity concentrations of anthropogenic 137Cs in ground level air, during the observed period, were at level 0.3 - 8 μBq m-3. The variations in 7Be/210Pb activity ratio for the investigated stations are also presented. [Projekat Ministarstva nauke Republike Srbije, br. III43009

Soil-to-plant transfer factor for Sr-90 and Cs-137

This study focuses on determination of soil to plant transfer factor (TF) of long lived radionuclides Sr-90 and Cs-137. Sr-90 and Cs-137 activity concentration in agricultural soil samples was ranged between lt 0.3 and 1.3 Bq kg(-1) and 14 and 30 Bq kg(-1), from lt 2.6 to 7.2 Bq kg(-1) and 5 to 13 Bq kg(-1) fresh matter in roots and from 0.4 to 1.1 Bq kg(-1) and lt 0.2 to 0.7 Bq kg(-1) fresh matter in the rest parts of plant, respectively. Calculated values for Sr-90 and Cs-137 TF from soil to plant ranged from 0.57 to 11.2 and 0.01 to 0.43, respectively

Distribution of natural and artificial radionuclides in chernozem soil/crop system from stationary experiments

n The present paper focuses on the determination of radiological characteristics of cultivated chernozem soil and crops from long-term field experiments, taking into account the importance of distribution and transfer of radionuclides in the soil-plant system, especially in agricultural cropland. The investigation was performed on the experimental fields where maize, winter wheat, and rapeseed were cultivated. Analysis of radioactivity included determination of the gross alpha and beta activity as a screening method, as well as the activities of the following radiouclides: natural (Pb-210, U-235, U-238, Ra-226, Th-232, K-40, Be-7) and artificial (Sr-90 and Cs-137). The activities of natural and artificial (Cs-137) radionuclides were determined by gamma spectrometry, while the artificial radionuclide Sr-90 was determined by a radiochemical analytical method. Based on the obtained results for the specific activity of K-40, Cs-137, and Sr-90, accumulation factors for these radionuclides were calculated in order to estimate transfer of radionuclides from soil to crops. The results of performed analyses showed that there is no increase of radioactivity that could endanger the food production through the grown crops