TY  - CONF
AU  - Jovanović, Vojislav D.
AU  - Samaržija-Jovanović, Suzana
AU  - Jevtić, Sonja
AU  - Petković, Branka B.
AU  - Marković, Gordana S.
AU  - Marinović-Cincović, Milena
PY  - 2018
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/12692
AB  - Zbog emisije formaldehida (CH2 O) iz drvenih proizvoda, gde se urea- formaldehidne (UF) smole, između ostalog, koriste za impregnaciju drvenih panela koje se koriste u unutrašnjosti stambenih i drugih objekata poželjno je da procenat slobodnog formaldehida (CH2 O) u samoj smoli bude što manji, jer je poznato da formaldehid ima štetno dejstvo na čoveka, odnosno ceo živi svet. Pare formaldehida jako nadražuju disajne puteve. Koncentracije od 10-20 ppm otežavaju disanje, a koncentracije od 650 ppm mogu uzrokovati i smrt za samo nekoliko minuta. Često udisanje para niskih koncentracija mogu uzrokovati hronična oboljenja disajnih puteva. Simptomi i granice su individualni i javljaju se u širokim granicama izloženosti. Pojedine osobe mogu da osete simptome, kao što su iritacija očiju, grla, umor, glavobolja i mučnina, usled izloženosti i niskoj koncentaciji formaldehida (0.1 do 1 ppm). Osim slobodnog formaldehida, u samoj smoli, koji se spontano emituje, zbog niske otpornosti na vlagu, može doći do hidrolize UF smole što podrazumeva raskidanje samih veza u smoli (metilenetarskih) i dodatne emisije formaldehida u okolinu [1,2]. U ovom radu je ispitivana hidrolitička stabilnost modifikovanih UF smola sa “hvatačima” formaldehida, TiO2  sa različitim sadržajem (3,75 g i 7,25 g) u UF smoli i kombinacijom TiO2  i drvnog brašna (TiO2 /DB) u ekvimolarnim količinama. Tri modifikovane UF smole s odnosom formaldehida i uree (F/U) 0.8 s modifikovanim punilima su sintetizovani istim postupkom [3]. Hidrolitička stabilnost ispitivanih modifikovanih UF smola je određivana merenjem koncentracije oslobođenog formaldehida [4] iz modifikovane UF smole nakon kisele hidrolize. Zračenje sintetisanih modifikovanih smola je vršeno u vazdušnoj atmosferi u Co-60 radijacionoj jedinici na Institutu za nuklearne nauke, Vinča, Srbija. Uzorci smola su zračeni γ–zračenjem na sobnoj temperaturi i ukupnom apsorbovanom dozom od 50 kGy i 100 kGy [5]. Pre zračenja najmanji procenat slobodnog formaldehida (0.06%) imaju uzorci koji su modifikovani TiO2 . Usled γ-zračenja dolazi do degradacije makromolekula što uzrokuje povećanje slobodnog formaldehida u zračenim uzorcima u odnosu na nezračene. Povećanje doze zračenja sa 50 kGy na 100 kGy dovodi do smanjenja količine slobodnog formaldehida u umreženoj UF smoli. Najmanji procenat slobodnog formaldehida nakon zračenja sa ukupnom apsorbovanom dozom od 100 kGy nalazi se u UF smoli koja sadrži 100% TiO2 u količini od 0.12%. S druge strane i drvno brašno koje sadrži celulozu i hemicelulozu ima veliki broj hidroksilnih grupa, takođe reaguje sa slobodnim formaldehidom iz UF smole. γ-zračenjem je smanjen procenat oslobođenog formaldehida u svim ispitivanim modifikovanim UF smolama, posebno kod uzoraka smole sa TiO2  u količini od 100% u izosu od 0.25%. To se objašnjava činjenicom da kisela hidroliza nakon zračenja dovodi do dodatnog umrežavanja u svim uzorcima, što rezultuje „hvatanjem“ formaldehida u toku samog procesa hidrolize. Uzorci ispitivane kompozitne smole sa TiO2 /DB pokazuju lošiju hidrolitičku stabilnot zbog povećane interakcije između hidroksilnih i karbonilnih grupa u drvnom brašnu i hidroksilnih grupa sa površine TiO2 , zbog čega dolazi do smanjene interakcije hibridnog punila sa polimernom matricom odnosno smanjuje se procenat slobodnih grupa koje bi inače reagovale sa formaldehidom i smanjile njegovu emisiju iz smole.
PB  - Belgrade : Serbian Chemical Society
C3  - ENVIROCHEM 2018 : 8th Symposium Chemistry and Environmental Protection : program and the book of abstracts
T1  - Uticaj različitih doza γ-zračenja na hidrolitičku stabilnost modifikovanih urea-formaldehidnih (UF) smola
T1  - The influence of different doses of γ-radiation on the hydrolytic stability of modified urea-formaldehyde (UF) resins
SP  - 109
EP  - 110
UR  - https://hdl.handle.net/21.15107/rcub_vinar_12692
ER  - 

@conference{
author = "Jovanović, Vojislav D. and Samaržija-Jovanović, Suzana and Jevtić, Sonja and Petković, Branka B. and Marković, Gordana S. and Marinović-Cincović, Milena",
year = "2018",
abstract = "Zbog emisije formaldehida (CH2 O) iz drvenih proizvoda, gde se urea- formaldehidne (UF) smole, između ostalog, koriste za impregnaciju drvenih panela koje se koriste u unutrašnjosti stambenih i drugih objekata poželjno je da procenat slobodnog formaldehida (CH2 O) u samoj smoli bude što manji, jer je poznato da formaldehid ima štetno dejstvo na čoveka, odnosno ceo živi svet. Pare formaldehida jako nadražuju disajne puteve. Koncentracije od 10-20 ppm otežavaju disanje, a koncentracije od 650 ppm mogu uzrokovati i smrt za samo nekoliko minuta. Često udisanje para niskih koncentracija mogu uzrokovati hronična oboljenja disajnih puteva. Simptomi i granice su individualni i javljaju se u širokim granicama izloženosti. Pojedine osobe mogu da osete simptome, kao što su iritacija očiju, grla, umor, glavobolja i mučnina, usled izloženosti i niskoj koncentaciji formaldehida (0.1 do 1 ppm). Osim slobodnog formaldehida, u samoj smoli, koji se spontano emituje, zbog niske otpornosti na vlagu, može doći do hidrolize UF smole što podrazumeva raskidanje samih veza u smoli (metilenetarskih) i dodatne emisije formaldehida u okolinu [1,2]. U ovom radu je ispitivana hidrolitička stabilnost modifikovanih UF smola sa “hvatačima” formaldehida, TiO2  sa različitim sadržajem (3,75 g i 7,25 g) u UF smoli i kombinacijom TiO2  i drvnog brašna (TiO2 /DB) u ekvimolarnim količinama. Tri modifikovane UF smole s odnosom formaldehida i uree (F/U) 0.8 s modifikovanim punilima su sintetizovani istim postupkom [3]. Hidrolitička stabilnost ispitivanih modifikovanih UF smola je određivana merenjem koncentracije oslobođenog formaldehida [4] iz modifikovane UF smole nakon kisele hidrolize. Zračenje sintetisanih modifikovanih smola je vršeno u vazdušnoj atmosferi u Co-60 radijacionoj jedinici na Institutu za nuklearne nauke, Vinča, Srbija. Uzorci smola su zračeni γ–zračenjem na sobnoj temperaturi i ukupnom apsorbovanom dozom od 50 kGy i 100 kGy [5]. Pre zračenja najmanji procenat slobodnog formaldehida (0.06%) imaju uzorci koji su modifikovani TiO2 . Usled γ-zračenja dolazi do degradacije makromolekula što uzrokuje povećanje slobodnog formaldehida u zračenim uzorcima u odnosu na nezračene. Povećanje doze zračenja sa 50 kGy na 100 kGy dovodi do smanjenja količine slobodnog formaldehida u umreženoj UF smoli. Najmanji procenat slobodnog formaldehida nakon zračenja sa ukupnom apsorbovanom dozom od 100 kGy nalazi se u UF smoli koja sadrži 100% TiO2 u količini od 0.12%. S druge strane i drvno brašno koje sadrži celulozu i hemicelulozu ima veliki broj hidroksilnih grupa, takođe reaguje sa slobodnim formaldehidom iz UF smole. γ-zračenjem je smanjen procenat oslobođenog formaldehida u svim ispitivanim modifikovanim UF smolama, posebno kod uzoraka smole sa TiO2  u količini od 100% u izosu od 0.25%. To se objašnjava činjenicom da kisela hidroliza nakon zračenja dovodi do dodatnog umrežavanja u svim uzorcima, što rezultuje „hvatanjem“ formaldehida u toku samog procesa hidrolize. Uzorci ispitivane kompozitne smole sa TiO2 /DB pokazuju lošiju hidrolitičku stabilnot zbog povećane interakcije između hidroksilnih i karbonilnih grupa u drvnom brašnu i hidroksilnih grupa sa površine TiO2 , zbog čega dolazi do smanjene interakcije hibridnog punila sa polimernom matricom odnosno smanjuje se procenat slobodnih grupa koje bi inače reagovale sa formaldehidom i smanjile njegovu emisiju iz smole.",
publisher = "Belgrade : Serbian Chemical Society",
journal = "ENVIROCHEM 2018 : 8th Symposium Chemistry and Environmental Protection : program and the book of abstracts",
title = "Uticaj različitih doza γ-zračenja na hidrolitičku stabilnost modifikovanih urea-formaldehidnih (UF) smola, The influence of different doses of γ-radiation on the hydrolytic stability of modified urea-formaldehyde (UF) resins",
pages = "109-110",
url = "https://hdl.handle.net/21.15107/rcub_vinar_12692"
}

Jovanović, V. D., Samaržija-Jovanović, S., Jevtić, S., Petković, B. B., Marković, G. S.,& Marinović-Cincović, M.. (2018). Uticaj različitih doza γ-zračenja na hidrolitičku stabilnost modifikovanih urea-formaldehidnih (UF) smola. in ENVIROCHEM 2018 : 8th Symposium Chemistry and Environmental Protection : program and the book of abstracts
Belgrade : Serbian Chemical Society., 109-110.
https://hdl.handle.net/21.15107/rcub_vinar_12692

Jovanović VD, Samaržija-Jovanović S, Jevtić S, Petković BB, Marković GS, Marinović-Cincović M. Uticaj različitih doza γ-zračenja na hidrolitičku stabilnost modifikovanih urea-formaldehidnih (UF) smola. in ENVIROCHEM 2018 : 8th Symposium Chemistry and Environmental Protection : program and the book of abstracts. 2018;:109-110.
https://hdl.handle.net/21.15107/rcub_vinar_12692 .

Jovanović, Vojislav D., Samaržija-Jovanović, Suzana, Jevtić, Sonja, Petković, Branka B., Marković, Gordana S., Marinović-Cincović, Milena, "Uticaj različitih doza γ-zračenja na hidrolitičku stabilnost modifikovanih urea-formaldehidnih (UF) smola" in ENVIROCHEM 2018 : 8th Symposium Chemistry and Environmental Protection : program and the book of abstracts (2018):109-110,
https://hdl.handle.net/21.15107/rcub_vinar_12692 .

TY  - CONF
AU  - Jovanović, Vojislav D.
AU  - Jevtić, Sonja
AU  - Vukojević, Vesna
AU  - Đurđić, Slađana
AU  - Pergal, Marija
AU  - Manojlović, Dragan
AU  - Petković, Branka B.
AU  - Stanković, Dalibor
PY  - 2018
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/12693
AB  - Pethoxamid (POA) is relatively new herbicide and it belongs to group of chloroacetamides. It inhibits the germination of target weeds in corn, soybeans, peas and beans, tobacco and other crops and it can affects on herbicide-resistant weeds. There are no many research records about this, in the future quite applicable, herbicide. Bearing in mind that pethoxamid is high soluble in water, with almost no sorption in soils [1], the leaching and runoff of this compound in ground and surface water is a real threat. Pethoxamid residues in soil, water food and feed of plant origin usually were determined by using liquid chromatography with tandem mass spectrometry (LC–MS/MS) [2] while some other analytical methods were used for determination of pesticides [3]. The electroanalytical methods are noted as fast and cost-effective analytical methods for determination of many analytes of environmental interest. As far as we know, this is a first report about electrochemical behavior of herbicide pethoxamid and its electroanalytical determination. This method is based on the electrochemical oxidation of pethoxamid in Britton-Robinson buffer solution at pH 4 at a boron-doped diamond electrode. This type of carbon electrode is almost resistant to contamination of surface with various chemical spaces, easy to maintain and has a very wide working potential window which could provide insight into the electrochemical oxidation of pethoxamid at high anodic potentials. All electrochemical measurements (cyclic and square-wave voltammetry) were performed on PalmSens 3 potentiostat/galvanostat/impedance analyzer with PSTrace software (PalmSens BV, Netherlands). Three-electrode system in the electrochemical cell was consisted from Ag/AgCl (1M KCl) reference electrode and platinum wire counter electrode, while working electrode was boron-doped diamond electrode. BDD electrode was electrochemicaly prepared as it was written before [4]. Cyclic voltammetry provided a well defined oxidation peak at +1.35 V, and this peak was used as a peak of quantification at a optimal pH value 4 (Figure 1 a). The square-wave voltammetry was chosen as suitable technique for analytical determination of pethoxamid with an established optimal working conditions (pulse amplitude of 60 mV and frequency of 10 Hz). The method was applied for selective quantification of pethoxamid from spiked river water samples with good recovery of 92.0 to 104.6% for standard solutions of POA and good agreement with comparative HPLC method (97.6-98.1%). The results of this research indicate successful, fast, simple, reliable and cheap estimation of pethoxamid content in the surface water samples with no electrode surface modification and time-consuming sample preparation.
PB  - Belgrade : Serbian Chemical Society
C3  - ENVIROCHEM 2018 : 8th Symposium Chemistry and Environmental Protection : program and the book of abstracts
T1  - First study of electrochemical behavior of herbicide pethoxamid and its voltammetric determination in river water
SP  - 111
EP  - 112
UR  - https://hdl.handle.net/21.15107/rcub_vinar_12693
ER  - 

@conference{
author = "Jovanović, Vojislav D. and Jevtić, Sonja and Vukojević, Vesna and Đurđić, Slađana and Pergal, Marija and Manojlović, Dragan and Petković, Branka B. and Stanković, Dalibor",
year = "2018",
abstract = "Pethoxamid (POA) is relatively new herbicide and it belongs to group of chloroacetamides. It inhibits the germination of target weeds in corn, soybeans, peas and beans, tobacco and other crops and it can affects on herbicide-resistant weeds. There are no many research records about this, in the future quite applicable, herbicide. Bearing in mind that pethoxamid is high soluble in water, with almost no sorption in soils [1], the leaching and runoff of this compound in ground and surface water is a real threat. Pethoxamid residues in soil, water food and feed of plant origin usually were determined by using liquid chromatography with tandem mass spectrometry (LC–MS/MS) [2] while some other analytical methods were used for determination of pesticides [3]. The electroanalytical methods are noted as fast and cost-effective analytical methods for determination of many analytes of environmental interest. As far as we know, this is a first report about electrochemical behavior of herbicide pethoxamid and its electroanalytical determination. This method is based on the electrochemical oxidation of pethoxamid in Britton-Robinson buffer solution at pH 4 at a boron-doped diamond electrode. This type of carbon electrode is almost resistant to contamination of surface with various chemical spaces, easy to maintain and has a very wide working potential window which could provide insight into the electrochemical oxidation of pethoxamid at high anodic potentials. All electrochemical measurements (cyclic and square-wave voltammetry) were performed on PalmSens 3 potentiostat/galvanostat/impedance analyzer with PSTrace software (PalmSens BV, Netherlands). Three-electrode system in the electrochemical cell was consisted from Ag/AgCl (1M KCl) reference electrode and platinum wire counter electrode, while working electrode was boron-doped diamond electrode. BDD electrode was electrochemicaly prepared as it was written before [4]. Cyclic voltammetry provided a well defined oxidation peak at +1.35 V, and this peak was used as a peak of quantification at a optimal pH value 4 (Figure 1 a). The square-wave voltammetry was chosen as suitable technique for analytical determination of pethoxamid with an established optimal working conditions (pulse amplitude of 60 mV and frequency of 10 Hz). The method was applied for selective quantification of pethoxamid from spiked river water samples with good recovery of 92.0 to 104.6% for standard solutions of POA and good agreement with comparative HPLC method (97.6-98.1%). The results of this research indicate successful, fast, simple, reliable and cheap estimation of pethoxamid content in the surface water samples with no electrode surface modification and time-consuming sample preparation.",
publisher = "Belgrade : Serbian Chemical Society",
journal = "ENVIROCHEM 2018 : 8th Symposium Chemistry and Environmental Protection : program and the book of abstracts",
title = "First study of electrochemical behavior of herbicide pethoxamid and its voltammetric determination in river water",
pages = "111-112",
url = "https://hdl.handle.net/21.15107/rcub_vinar_12693"
}

Jovanović, V. D., Jevtić, S., Vukojević, V., Đurđić, S., Pergal, M., Manojlović, D., Petković, B. B.,& Stanković, D.. (2018). First study of electrochemical behavior of herbicide pethoxamid and its voltammetric determination in river water. in ENVIROCHEM 2018 : 8th Symposium Chemistry and Environmental Protection : program and the book of abstracts
Belgrade : Serbian Chemical Society., 111-112.
https://hdl.handle.net/21.15107/rcub_vinar_12693

Jovanović VD, Jevtić S, Vukojević V, Đurđić S, Pergal M, Manojlović D, Petković BB, Stanković D. First study of electrochemical behavior of herbicide pethoxamid and its voltammetric determination in river water. in ENVIROCHEM 2018 : 8th Symposium Chemistry and Environmental Protection : program and the book of abstracts. 2018;:111-112.
https://hdl.handle.net/21.15107/rcub_vinar_12693 .

Jovanović, Vojislav D., Jevtić, Sonja, Vukojević, Vesna, Đurđić, Slađana, Pergal, Marija, Manojlović, Dragan, Petković, Branka B., Stanković, Dalibor, "First study of electrochemical behavior of herbicide pethoxamid and its voltammetric determination in river water" in ENVIROCHEM 2018 : 8th Symposium Chemistry and Environmental Protection : program and the book of abstracts (2018):111-112,
https://hdl.handle.net/21.15107/rcub_vinar_12693 .