Optimization of Liquid Scintillation Spectrometer Quantulus 1220 for tritium determination in water samples after electrolytic enrichment

U radu je prikazana optimizacija uslova merenja na tečnom scintilacionom spektrometru Ultra Low Level Liquid Scintillation Spectrometer Quantulus 1220 u cilju određivanja tricijuma u uzorcima voda. Opisan je postupak određivanja efikasnosti, optimalnog odnosa zapremine uzorka i scintilacionog koktela i optimalno vreme merenja. Instrument je predviđen za merenje niskih aktivnosti tricijuma u uzorcima prirodnih voda. U tu svrhu uzorci površinskih voda i padavina su elektrolitički obogaćeni i kao takvi mereni na spektrometru. Rezultati pokazuju da su dobijene aktivnosti tricijuma u datim vodama ispod granica predvidjenih zakonskom regulativom.The paper presents the optimization of the measurement conditions for Ultra Low Level Liquid Scintillation Spectrometer Quantulus 1220 in order to determine the tritium activity in water samples after electrolytic enrichment. The procedure included determination of efficiency, background, minimal detectable activity, the optimal ratio of the sample volume and scintillation cocktail and the optimal measurement time. The instrument is designed to measure low activity of tritium in natural water samples. For this purpose, samples of surface waters and precipitation are electrolytically enriched and as such are measured on a spectrometer.Зборник радова : XXIX симпозијум ДЗЗСЦГ : Сребрно језеро, 27-29. септембар 2017. годин

Optimization of Liquid Scintillation Spectrometer Quantulus 1220 for tritium determination in water samples after electrolytic enrichment

U radu je prikazana optimizacija uslova merenja na tečnom scintilacionom spektrometru Ultra Low Level Liquid Scintillation Spectrometer Quantulus 1220 u cilju određivanja tricijuma u uzorcima voda. Opisan je postupak određivanja efikasnosti, optimalnog odnosa zapremine uzorka i scintilacionog koktela i optimalno vreme merenja. Instrument je predviđen za merenje niskih aktivnosti tricijuma u uzorcima prirodnih voda. U tu svrhu uzorci površinskih voda i padavina su elektrolitički obogaćeni i kao takvi mereni na spektrometru. Rezultati pokazuju da su dobijene aktivnosti tricijuma u datim vodama ispod granica predvidjenih zakonskom regulativom.The paper presents the optimization of the measurement conditions for Ultra Low Level Liquid Scintillation Spectrometer Quantulus 1220 in order to determine the tritium activity in water samples after electrolytic enrichment. The procedure included determination of efficiency, background, minimal detectable activity, the optimal ratio of the sample volume and scintillation cocktail and the optimal measurement time. The instrument is designed to measure low activity of tritium in natural water samples. For this purpose, samples of surface waters and precipitation are electrolytically enriched and as such are measured on a spectrometer.Зборник радова : XXIX симпозијум ДЗЗСЦГ : Сребрно језеро, 27-29. септембар 2017. годин

Degradation of linuron in soil by two fungal strains

Two fungal strains were applied to soil polluted with herbicide in order to determine their degradation potential. Three experimental setups were used. In the first setup, the soil in pots was contaminated by linuron in final concentration of 1 ppm. Suspensions of Phanerocheate chrysosporium and Trichoderma asperellum were applied sepa­rately or in combination. Tomato plantlets were transplanted and chlorophyll content in their leaves was determined at two time points during plant growth. In the second setup in pots, the final concentration of linuron was lower, 0.45 ppm. In the third setup 0.1 ppm of linuron was applied in the field plot. Plantlets of lettuce were transplanted and chlorophyll content was measured as indicator of plant stress. The content of linuron in soil was determined by HPLC. The applied fungal strains significantly reduced toxic effect of 0.45 ppm linuron on plants, which was not the case for 1 ppm linuron. Both fungi, applied separately or in combination, were effective in decreasing the linuron content in the soil. However, in field conditions the combination of both fungi was the most effective. [Projekat Ministarstva nauke Republike Srbije, br. III43010