TY  - CONF
AU  - Pantović Spajić, Katarina
AU  - Pantović Pavlović, Marijana
AU  - Božić, Katarina
AU  - Gjumišev, Đorđe
AU  - Panić, Vladimir
AU  - Pavlović, Miroslav
AU  - Stojanović, Ksenija
PY  - 2023
UR  - https://ritnms.itnms.ac.rs/handle/123456789/1119
AB  - The removal of organic and inorganic sulfur from the Bogovina Basin subbituminous coal by
electrochemical redox reactions was performed. The effect of presence of active bromine species
on the desulfurization process was monitored. The desulfurization was performed in inorganic
acidic solutions that contained different bromide concentrations and in pure acid solution. To
determine the optimal conditions for the desulfurization process, polarization curves were
recorded in three different electrolytes: 0.1 M H2SO4, 0.1 M H2SO4 + 0.01 M KBr, and 0.1 M
H2SO4 + 0.1 M KBr using graphite and dimensionally stable anode (DSA) electrodes as the
anode, while in all cases stainless steel S31603 electrode was used as cathode. By analyzing the
results obtained from the polarization curves, 0.1 M H2SO4 and 0.1 M H2SO4 + 0.1 M KBr were
chosen as the most suitable electrolytes. Also, it was found that the DSA anode showed better
results in terms of energy efficiency of the process compared to the graphite anode and therefore
it was selected for the coal desulfurization process. It is considered that finely suspended coal
particles in an electrolyte can behave according to bipolar electrochemistry. Coal was treated
for 4 hours in two selected electrolytes. The suspension was sampled at different times up to 240
min from the beginning of the process. Sulfur content in coal was determined by elemental
analysis. The results showed that the sulfur content decreases faster in the case of the electrolyte
containing KBr, i.e. that the desulfurization effect is significantly better than in the case of the
system containing only H2SO4. It can be concluded that active bromine species accelerate the
desulfurization process and thus improve energy efficiency.
PB  - Zvornik : University of East Sarajevo, Faculty of Technology
C3  - VIII International Congress “Engineering, Environment and Materials in Process Industry“
T1  - Study of the effects of active bromine species presence in electrolytic desulfurization of subbituminous coal
EP  - 64
SP  - 64
ER  - 

@conference{
author = "Pantović Spajić, Katarina and Pantović Pavlović, Marijana and Božić, Katarina and Gjumišev, Đorđe and Panić, Vladimir and Pavlović, Miroslav and Stojanović, Ksenija",
year = "2023",
abstract = "The removal of organic and inorganic sulfur from the Bogovina Basin subbituminous coal by
electrochemical redox reactions was performed. The effect of presence of active bromine species
on the desulfurization process was monitored. The desulfurization was performed in inorganic
acidic solutions that contained different bromide concentrations and in pure acid solution. To
determine the optimal conditions for the desulfurization process, polarization curves were
recorded in three different electrolytes: 0.1 M H2SO4, 0.1 M H2SO4 + 0.01 M KBr, and 0.1 M
H2SO4 + 0.1 M KBr using graphite and dimensionally stable anode (DSA) electrodes as the
anode, while in all cases stainless steel S31603 electrode was used as cathode. By analyzing the
results obtained from the polarization curves, 0.1 M H2SO4 and 0.1 M H2SO4 + 0.1 M KBr were
chosen as the most suitable electrolytes. Also, it was found that the DSA anode showed better
results in terms of energy efficiency of the process compared to the graphite anode and therefore
it was selected for the coal desulfurization process. It is considered that finely suspended coal
particles in an electrolyte can behave according to bipolar electrochemistry. Coal was treated
for 4 hours in two selected electrolytes. The suspension was sampled at different times up to 240
min from the beginning of the process. Sulfur content in coal was determined by elemental
analysis. The results showed that the sulfur content decreases faster in the case of the electrolyte
containing KBr, i.e. that the desulfurization effect is significantly better than in the case of the
system containing only H2SO4. It can be concluded that active bromine species accelerate the
desulfurization process and thus improve energy efficiency.",
publisher = "Zvornik : University of East Sarajevo, Faculty of Technology",
journal = "VIII International Congress “Engineering, Environment and Materials in Process Industry“",
title = "Study of the effects of active bromine species presence in electrolytic desulfurization of subbituminous coal",
pages = "64-64"
}

Pantović Spajić, K., Pantović Pavlović, M., Božić, K., Gjumišev, Đ., Panić, V., Pavlović, M.,& Stojanović, K.. (2023). Study of the effects of active bromine species presence in electrolytic desulfurization of subbituminous coal. in VIII International Congress “Engineering, Environment and Materials in Process Industry“
Zvornik : University of East Sarajevo, Faculty of Technology., 64-64.

Pantović Spajić K, Pantović Pavlović M, Božić K, Gjumišev Đ, Panić V, Pavlović M, Stojanović K. Study of the effects of active bromine species presence in electrolytic desulfurization of subbituminous coal. in VIII International Congress “Engineering, Environment and Materials in Process Industry“. 2023;:64-64..

Pantović Spajić, Katarina, Pantović Pavlović, Marijana, Božić, Katarina, Gjumišev, Đorđe, Panić, Vladimir, Pavlović, Miroslav, Stojanović, Ksenija, "Study of the effects of active bromine species presence in electrolytic desulfurization of subbituminous coal" in VIII International Congress “Engineering, Environment and Materials in Process Industry“ (2023):64-64.

TY  - JOUR
AU  - Stevanović, Jelena Z.
AU  - Rakitin, Anton
AU  - Kojić, Ivan
AU  - Vuković, Nikola
AU  - Stojanović, Ksenija
PY  - 2022
UR  - https://ritnms.itnms.ac.rs/handle/123456789/637
AB  - A detailed investigation of significance of the infrared (IR) spectroscopic branching factor (CH2/CH3; the ratio of methylene and methyl group peak heights at 2917-2921 and 2951-2954 cm(-1), respectively in the IR spectra) for characterization of alkane structure, geochemical properties and viscosity of 76 oil samples was performed. These oils, originating from 13 Serbian oil fields in SE Pannonian Basin, differ according to source and depositional environment of organic matter (OM), as well as by thermal maturity and biodegradation stage. Methylene and methyl asymmetric stretching peak absorbances were used for the branching factor calculation. CH2 peak positions exhibited 3-4 cm(-1) red shift with increasing the CH2/CH3 ratio, due to a greater contribution of trans vs. gauche rotamers in aliphatic chains. Comparing IR spectra of the oils and model n-alkanes, it was established that the average (CH2)(n) methylene chain length per CH3 group varied from n = 3.5 to 6.5. The CH2/CH3 ratio showed significant concordance with geochemical parameters, enabling clear distinction of the oils according to source and depositional environment of OM. At the same time, dependence of the CH2/CH3 ratio on oil maturity in the range from immature to mature was not observed, allowing for an accurate determination of oil genetic types irrespective of maturity. The CH2/CH3 ratio showed good accordance with oil biodegradation scale and oil viscosity.
PB  - Srpsko hemijsko društvo, Beograd
T2  - Journal of the Serbian Chemical Society
T1  - Significance of infrared spectroscopic branching factor for investigation of structural characteristics of alkanes, geochemical properties and viscosity of oils
EP  - 55
IS  - 1
SP  - 41
VL  - 87
DO  - 10.2298/JSC210830091S
UR  - conv_937
ER  - 

@article{
author = "Stevanović, Jelena Z. and Rakitin, Anton and Kojić, Ivan and Vuković, Nikola and Stojanović, Ksenija",
year = "2022",
abstract = "A detailed investigation of significance of the infrared (IR) spectroscopic branching factor (CH2/CH3; the ratio of methylene and methyl group peak heights at 2917-2921 and 2951-2954 cm(-1), respectively in the IR spectra) for characterization of alkane structure, geochemical properties and viscosity of 76 oil samples was performed. These oils, originating from 13 Serbian oil fields in SE Pannonian Basin, differ according to source and depositional environment of organic matter (OM), as well as by thermal maturity and biodegradation stage. Methylene and methyl asymmetric stretching peak absorbances were used for the branching factor calculation. CH2 peak positions exhibited 3-4 cm(-1) red shift with increasing the CH2/CH3 ratio, due to a greater contribution of trans vs. gauche rotamers in aliphatic chains. Comparing IR spectra of the oils and model n-alkanes, it was established that the average (CH2)(n) methylene chain length per CH3 group varied from n = 3.5 to 6.5. The CH2/CH3 ratio showed significant concordance with geochemical parameters, enabling clear distinction of the oils according to source and depositional environment of OM. At the same time, dependence of the CH2/CH3 ratio on oil maturity in the range from immature to mature was not observed, allowing for an accurate determination of oil genetic types irrespective of maturity. The CH2/CH3 ratio showed good accordance with oil biodegradation scale and oil viscosity.",
publisher = "Srpsko hemijsko društvo, Beograd",
journal = "Journal of the Serbian Chemical Society",
title = "Significance of infrared spectroscopic branching factor for investigation of structural characteristics of alkanes, geochemical properties and viscosity of oils",
pages = "55-41",
number = "1",
volume = "87",
doi = "10.2298/JSC210830091S",
url = "conv_937"
}

Stevanović, J. Z., Rakitin, A., Kojić, I., Vuković, N.,& Stojanović, K.. (2022). Significance of infrared spectroscopic branching factor for investigation of structural characteristics of alkanes, geochemical properties and viscosity of oils. in Journal of the Serbian Chemical Society
Srpsko hemijsko društvo, Beograd., 87(1), 41-55.
https://doi.org/10.2298/JSC210830091S
conv_937

Stevanović JZ, Rakitin A, Kojić I, Vuković N, Stojanović K. Significance of infrared spectroscopic branching factor for investigation of structural characteristics of alkanes, geochemical properties and viscosity of oils. in Journal of the Serbian Chemical Society. 2022;87(1):41-55.
doi:10.2298/JSC210830091S
conv_937 .

Stevanović, Jelena Z., Rakitin, Anton, Kojić, Ivan, Vuković, Nikola, Stojanović, Ksenija, "Significance of infrared spectroscopic branching factor for investigation of structural characteristics of alkanes, geochemical properties and viscosity of oils" in Journal of the Serbian Chemical Society, 87, no. 1 (2022):41-55,
https://doi.org/10.2298/JSC210830091S .,
conv_937 .

TY  - CONF
AU  - Pantović Spajić, Katarina
AU  - Marković, Branislav
AU  - Sokić, Miroslav
AU  - Jovanović, Gvozden
AU  - Stojanović, Ksenija
PY  - 2021
UR  - https://ritnms.itnms.ac.rs/handle/123456789/1124
AB  - Coal is a well-known fossil fuel. It was used as a non-renewable energy source for several centuries. Nowadays it is mainly used for electricity generation in power plants or heat generation for industrial and home utilization.
There are many types of coal that differ in composition and calorific value, as well as in the amounts of undesired hazard substances produced by combustion. Depending on the coal composition, environmental impact can be reduced by its treatment before combustion. One of the cheap and effective methods is the chemical leaching of coal that reduces sulfur content and the amount of mineral matter (ash). Lowering the ash amount increases the calorific value of coal, reduces its transportation cost, and reduces the negative environmental impact of toxic elements, which are usually present in ash. Another benefit of coal leaching, that results from lowering the sulfur content is reduced emission of toxic gases (SO2 and SO3) during combustion. In order to determine the optimal leaching conditions for the treatment of different types of coal, numerous studies have been done, investigating various chemical reagents, including inorganic and organic acids, alkalis, oxidative reagents, and their combinations [1, 2]. The key parameters that effect leaching efficiency are type and concentration of reagent, reaction temperature, the mass ratio between coal and leaching reagent, coal particle size, and reaction time. The degree of leaching efficiency is measured by the level of demineralization and desulphurization [3]. The current review summarises recent results and further plans for the development of an efficient and environmentally friendly method for the chemical leaching of Serbian sub-bituminous coal.
PB  - Belgrade : Innovation Center of Faculty of Mechanical Engineering
C3  - International Conference of Experimental and Numerical Investigations and New Technologies
T1  - A review of coal demineralization and desulphurization by chemical leaching
EP  - 99
SP  - 99
ER  - 

@conference{
author = "Pantović Spajić, Katarina and Marković, Branislav and Sokić, Miroslav and Jovanović, Gvozden and Stojanović, Ksenija",
year = "2021",
abstract = "Coal is a well-known fossil fuel. It was used as a non-renewable energy source for several centuries. Nowadays it is mainly used for electricity generation in power plants or heat generation for industrial and home utilization.
There are many types of coal that differ in composition and calorific value, as well as in the amounts of undesired hazard substances produced by combustion. Depending on the coal composition, environmental impact can be reduced by its treatment before combustion. One of the cheap and effective methods is the chemical leaching of coal that reduces sulfur content and the amount of mineral matter (ash). Lowering the ash amount increases the calorific value of coal, reduces its transportation cost, and reduces the negative environmental impact of toxic elements, which are usually present in ash. Another benefit of coal leaching, that results from lowering the sulfur content is reduced emission of toxic gases (SO2 and SO3) during combustion. In order to determine the optimal leaching conditions for the treatment of different types of coal, numerous studies have been done, investigating various chemical reagents, including inorganic and organic acids, alkalis, oxidative reagents, and their combinations [1, 2]. The key parameters that effect leaching efficiency are type and concentration of reagent, reaction temperature, the mass ratio between coal and leaching reagent, coal particle size, and reaction time. The degree of leaching efficiency is measured by the level of demineralization and desulphurization [3]. The current review summarises recent results and further plans for the development of an efficient and environmentally friendly method for the chemical leaching of Serbian sub-bituminous coal.",
publisher = "Belgrade : Innovation Center of Faculty of Mechanical Engineering",
journal = "International Conference of Experimental and Numerical Investigations and New Technologies",
title = "A review of coal demineralization and desulphurization by chemical leaching",
pages = "99-99"
}

Pantović Spajić, K., Marković, B., Sokić, M., Jovanović, G.,& Stojanović, K.. (2021). A review of coal demineralization and desulphurization by chemical leaching. in International Conference of Experimental and Numerical Investigations and New Technologies
Belgrade : Innovation Center of Faculty of Mechanical Engineering., 99-99.

Pantović Spajić K, Marković B, Sokić M, Jovanović G, Stojanović K. A review of coal demineralization and desulphurization by chemical leaching. in International Conference of Experimental and Numerical Investigations and New Technologies. 2021;:99-99..

Pantović Spajić, Katarina, Marković, Branislav, Sokić, Miroslav, Jovanović, Gvozden, Stojanović, Ksenija, "A review of coal demineralization and desulphurization by chemical leaching" in International Conference of Experimental and Numerical Investigations and New Technologies (2021):99-99.

TY  - CONF
AU  - Pantović Spajić, Katarina
AU  - Marković, Branislav
AU  - Sokić, Miroslav
AU  - Bugarčić, Mladen
AU  - Jovanović, Gvozden
AU  - Manojlović, Vaso
AU  - Stojanović, Ksenija
PY  - 2021
UR  - https://ritnms.itnms.ac.rs/handle/123456789/1122
AB  - All over the world, huge amounts of coal are available and it is utilized in large quantities for different
purposes. The coal combustion causes environmental problems, such as the release of toxic metals
and other pollutants into wastewaters, emission of noxious gases, produce of ash dumps, etc. One of
the solutions for the reduction of environment pollution, caused by coal combustion, is
demineralization and desulphurization of coal. In that sense, treatment of coal by different chemical
reagents becomes important. A subbituminous coal, used in this study was taken from the Bogovina -
East field (Lower Miocene » 20-16 Ma) of the Bogovina Basin, which is located in Eastern Serbia. The
sample was selected based on the previous studies of Bogovina - East field which indicated a high
amount of sulphur, relatively high percent of mineral matter and considerably amount of liptinites
for humic coal, which represent the most reactive maceral group. The aim of the study was an
attempt to reduce the amount of ash and sulphur in coal, keeping the organic matter unaltered as
possible, using simple and cheap method e.g. treatment with hydrochloric acid (HCl). Ash and total
sulphur content was determined before and after HCl leaching. In addition characteristics of initial
and treated coal were tracked by X-ray diffraction (XRD) analysis and Fourier-transform infrared
(FTIR) spectroscopy. The obtained results showed that the high percentage of deashing (» 80 %) was
achieved with cheap hydrochloric acid. XRD analysis of ash before and after sample treatment
provides more information about mineral phases in coal and effects of chemical leaching. FTIR
analysis indicates almost no changes in structure of coal organic matter after treatment by HCl,
which is important for further coal usage (e.g. combustion). On the other hand, the applied chemical
leaching with HCl had low impact on the sulphur content in Bogovina coal (desulphurization
percentage » 8 %). Therefore, in future research other reagents for efficient desulphurization should
be investigated.
PB  - Sisak : Univerzitet u Zagrebu, Metalurški Fakultet
C3  - 19th INTERNATIONAL FOUNDRYMEN CONFERENCE
T1  - "Chemical leaching of subbituminous coal from the Bogovina - East field (Bogovina basin, Serbia) using hydrochloric acid"
EP  - 440
SP  - 435
ER  - 

@conference{
author = "Pantović Spajić, Katarina and Marković, Branislav and Sokić, Miroslav and Bugarčić, Mladen and Jovanović, Gvozden and Manojlović, Vaso and Stojanović, Ksenija",
year = "2021",
abstract = "All over the world, huge amounts of coal are available and it is utilized in large quantities for different
purposes. The coal combustion causes environmental problems, such as the release of toxic metals
and other pollutants into wastewaters, emission of noxious gases, produce of ash dumps, etc. One of
the solutions for the reduction of environment pollution, caused by coal combustion, is
demineralization and desulphurization of coal. In that sense, treatment of coal by different chemical
reagents becomes important. A subbituminous coal, used in this study was taken from the Bogovina -
East field (Lower Miocene » 20-16 Ma) of the Bogovina Basin, which is located in Eastern Serbia. The
sample was selected based on the previous studies of Bogovina - East field which indicated a high
amount of sulphur, relatively high percent of mineral matter and considerably amount of liptinites
for humic coal, which represent the most reactive maceral group. The aim of the study was an
attempt to reduce the amount of ash and sulphur in coal, keeping the organic matter unaltered as
possible, using simple and cheap method e.g. treatment with hydrochloric acid (HCl). Ash and total
sulphur content was determined before and after HCl leaching. In addition characteristics of initial
and treated coal were tracked by X-ray diffraction (XRD) analysis and Fourier-transform infrared
(FTIR) spectroscopy. The obtained results showed that the high percentage of deashing (» 80 %) was
achieved with cheap hydrochloric acid. XRD analysis of ash before and after sample treatment
provides more information about mineral phases in coal and effects of chemical leaching. FTIR
analysis indicates almost no changes in structure of coal organic matter after treatment by HCl,
which is important for further coal usage (e.g. combustion). On the other hand, the applied chemical
leaching with HCl had low impact on the sulphur content in Bogovina coal (desulphurization
percentage » 8 %). Therefore, in future research other reagents for efficient desulphurization should
be investigated.",
publisher = "Sisak : Univerzitet u Zagrebu, Metalurški Fakultet",
journal = "19th INTERNATIONAL FOUNDRYMEN CONFERENCE",
title = ""Chemical leaching of subbituminous coal from the Bogovina - East field (Bogovina basin, Serbia) using hydrochloric acid"",
pages = "440-435"
}

Pantović Spajić, K., Marković, B., Sokić, M., Bugarčić, M., Jovanović, G., Manojlović, V.,& Stojanović, K.. (2021). "Chemical leaching of subbituminous coal from the Bogovina - East field (Bogovina basin, Serbia) using hydrochloric acid". in 19th INTERNATIONAL FOUNDRYMEN CONFERENCE
Sisak : Univerzitet u Zagrebu, Metalurški Fakultet., 435-440.

Pantović Spajić K, Marković B, Sokić M, Bugarčić M, Jovanović G, Manojlović V, Stojanović K. "Chemical leaching of subbituminous coal from the Bogovina - East field (Bogovina basin, Serbia) using hydrochloric acid". in 19th INTERNATIONAL FOUNDRYMEN CONFERENCE. 2021;:435-440..

Pantović Spajić, Katarina, Marković, Branislav, Sokić, Miroslav, Bugarčić, Mladen, Jovanović, Gvozden, Manojlović, Vaso, Stojanović, Ksenija, ""Chemical leaching of subbituminous coal from the Bogovina - East field (Bogovina basin, Serbia) using hydrochloric acid"" in 19th INTERNATIONAL FOUNDRYMEN CONFERENCE (2021):435-440.

TY  - JOUR
AU  - Pantović-Spajić, Katarina
AU  - Marković, Branislav
AU  - Pavlović, Miroslav M.
AU  - Sokić, Miroslav
AU  - Zildžović, Snežana
AU  - Đorđević, Nataša
AU  - Stojanović, Ksenija
PY  - 2021
UR  - https://ritnms.itnms.ac.rs/handle/123456789/575
AB  - The study is focused on the determination of the most effective chemical leaching process for the simultaneous demineralization/deashing and desulfurization of subbituminous coal from the Bogovina Basin. Coal was treated for 30 min, at different temperatures, using variable concentrations of hydrochloric, nitric, acetic and citric acids; hydrogen peroxide, mixture of hydrogen peroxide and nitric acid (pH 2), as well as by the stepwise leaching process (nitric acid + mixture of hydrogen peroxide and nitric acid, pH 2). The changes in mineral composition, caused by the chemical leaching, are followed using X-ray diffraction, whereas alterations of coal organic matter are tracked by Fourier-transform infrared spectroscopy and the content of fixed carbon. Inorganic acid leaching, regardless of the temperature and acid concentration, enabled the successful deashing of coal, whereas the percent of desulfurization was insufficient. The organic acid leaching was not satisfactory for both, deashing and desulfurization. Leaching by H2O2 and H2O2/HNO3 mixture (pH 2) resulted in moderate desulfurization, but the ash reduction was low. The most suitable method for the simultaneous effective ash (78 wt.%) and the sulfur (66 wt. %) removal from Bogovina coal is the two-step leaching, combining 10 vol. % HNO3 and mixture of 35 vol. % H2O2/10 vol. % HNO3 of pH 2 at 60 degrees C.
PB  - Srpsko hemijsko društvo, Beograd
T2  - Journal of the Serbian Chemical Society
T1  - Deashing and desulfurization of subbituminous coal from the East field (Bogovina Basin, Serbia) - Insights from chemical leaching
EP  - 1126
IS  - 11
SP  - 1113
VL  - 86
DO  - 10.2298/JSC210719061P
UR  - conv_924
ER  - 

@article{
author = "Pantović-Spajić, Katarina and Marković, Branislav and Pavlović, Miroslav M. and Sokić, Miroslav and Zildžović, Snežana and Đorđević, Nataša and Stojanović, Ksenija",
year = "2021",
abstract = "The study is focused on the determination of the most effective chemical leaching process for the simultaneous demineralization/deashing and desulfurization of subbituminous coal from the Bogovina Basin. Coal was treated for 30 min, at different temperatures, using variable concentrations of hydrochloric, nitric, acetic and citric acids; hydrogen peroxide, mixture of hydrogen peroxide and nitric acid (pH 2), as well as by the stepwise leaching process (nitric acid + mixture of hydrogen peroxide and nitric acid, pH 2). The changes in mineral composition, caused by the chemical leaching, are followed using X-ray diffraction, whereas alterations of coal organic matter are tracked by Fourier-transform infrared spectroscopy and the content of fixed carbon. Inorganic acid leaching, regardless of the temperature and acid concentration, enabled the successful deashing of coal, whereas the percent of desulfurization was insufficient. The organic acid leaching was not satisfactory for both, deashing and desulfurization. Leaching by H2O2 and H2O2/HNO3 mixture (pH 2) resulted in moderate desulfurization, but the ash reduction was low. The most suitable method for the simultaneous effective ash (78 wt.%) and the sulfur (66 wt. %) removal from Bogovina coal is the two-step leaching, combining 10 vol. % HNO3 and mixture of 35 vol. % H2O2/10 vol. % HNO3 of pH 2 at 60 degrees C.",
publisher = "Srpsko hemijsko društvo, Beograd",
journal = "Journal of the Serbian Chemical Society",
title = "Deashing and desulfurization of subbituminous coal from the East field (Bogovina Basin, Serbia) - Insights from chemical leaching",
pages = "1126-1113",
number = "11",
volume = "86",
doi = "10.2298/JSC210719061P",
url = "conv_924"
}

Pantović-Spajić, K., Marković, B., Pavlović, M. M., Sokić, M., Zildžović, S., Đorđević, N.,& Stojanović, K.. (2021). Deashing and desulfurization of subbituminous coal from the East field (Bogovina Basin, Serbia) - Insights from chemical leaching. in Journal of the Serbian Chemical Society
Srpsko hemijsko društvo, Beograd., 86(11), 1113-1126.
https://doi.org/10.2298/JSC210719061P
conv_924

Pantović-Spajić K, Marković B, Pavlović MM, Sokić M, Zildžović S, Đorđević N, Stojanović K. Deashing and desulfurization of subbituminous coal from the East field (Bogovina Basin, Serbia) - Insights from chemical leaching. in Journal of the Serbian Chemical Society. 2021;86(11):1113-1126.
doi:10.2298/JSC210719061P
conv_924 .

Pantović-Spajić, Katarina, Marković, Branislav, Pavlović, Miroslav M., Sokić, Miroslav, Zildžović, Snežana, Đorđević, Nataša, Stojanović, Ksenija, "Deashing and desulfurization of subbituminous coal from the East field (Bogovina Basin, Serbia) - Insights from chemical leaching" in Journal of the Serbian Chemical Society, 86, no. 11 (2021):1113-1126,
https://doi.org/10.2298/JSC210719061P .,
conv_924 .

TY  - CONF
AU  - Pantović Spajić, Katarina
AU  - Stojanović, Ksenija
AU  - Sakan, Sanja
AU  - Đorđević, Dragana
PY  - 2019
UR  - https://ritnms.itnms.ac.rs/handle/123456789/1120
AB  - The consequence of elevated values of toxic pollutants, which originate from numerous human
activities, is contaminated environment [1]. Rapid development of industry and agriculture
contributed to increase in heavy metals in invertebrates, fish and humans [2]. Heavy metals
accumulate in sediments over time which might be a trigger for numerous human diseases due to
possibility of transport of these metals in water medium and entering the food chain [3].
The aim of this study was the estimation of element contamination level in sediments of the important
rivers, accumulation and their tributaries in Serbia. The determination of the sample contents of the 4
elements (Cd, Ni, Sb and V) was conducted by the one-step extraction with inductively coupled
plasma atomic emission spectrometry (ICP OES). Extraction was done with three different acidic
extraction agents. Total of 33 samples of sediments from 16 major river and their tributaries in Serbia
wereanalyzed. The analyzed sediments showed high concentrations of Cd and Ni, which may have
great negative environmental impacts.
In sediments from Zapadna and Južna Morava, Tisa and river Pek the highest concentrations of Cd
was detected. The concentrations of Ni were above maximum permissible concentration in Vrutci and
Zapadna Morava river sediments. Results showed that the content of Sb was low in majority of the
samples. The highest content of V was extracted from Barje sediment sample.
PB  - Bor : University of Belgrade, Technical Faculty in Bor
C3  - 6th INTERNATIONAL STUDENT CONFERENCE ON TECHNICAL SCIENCES
T1  - One-step extraction of Cd, Ni, Sb and V applied to the river and accumulation sediments located in Serbia
EP  - 6
SP  - 6
ER  - 

@conference{
author = "Pantović Spajić, Katarina and Stojanović, Ksenija and Sakan, Sanja and Đorđević, Dragana",
year = "2019",
abstract = "The consequence of elevated values of toxic pollutants, which originate from numerous human
activities, is contaminated environment [1]. Rapid development of industry and agriculture
contributed to increase in heavy metals in invertebrates, fish and humans [2]. Heavy metals
accumulate in sediments over time which might be a trigger for numerous human diseases due to
possibility of transport of these metals in water medium and entering the food chain [3].
The aim of this study was the estimation of element contamination level in sediments of the important
rivers, accumulation and their tributaries in Serbia. The determination of the sample contents of the 4
elements (Cd, Ni, Sb and V) was conducted by the one-step extraction with inductively coupled
plasma atomic emission spectrometry (ICP OES). Extraction was done with three different acidic
extraction agents. Total of 33 samples of sediments from 16 major river and their tributaries in Serbia
wereanalyzed. The analyzed sediments showed high concentrations of Cd and Ni, which may have
great negative environmental impacts.
In sediments from Zapadna and Južna Morava, Tisa and river Pek the highest concentrations of Cd
was detected. The concentrations of Ni were above maximum permissible concentration in Vrutci and
Zapadna Morava river sediments. Results showed that the content of Sb was low in majority of the
samples. The highest content of V was extracted from Barje sediment sample.",
publisher = "Bor : University of Belgrade, Technical Faculty in Bor",
journal = "6th INTERNATIONAL STUDENT CONFERENCE ON TECHNICAL SCIENCES",
title = "One-step extraction of Cd, Ni, Sb and V applied to the river and accumulation sediments located in Serbia",
pages = "6-6"
}

Pantović Spajić, K., Stojanović, K., Sakan, S.,& Đorđević, D.. (2019). One-step extraction of Cd, Ni, Sb and V applied to the river and accumulation sediments located in Serbia. in 6th INTERNATIONAL STUDENT CONFERENCE ON TECHNICAL SCIENCES
Bor : University of Belgrade, Technical Faculty in Bor., 6-6.

Pantović Spajić K, Stojanović K, Sakan S, Đorđević D. One-step extraction of Cd, Ni, Sb and V applied to the river and accumulation sediments located in Serbia. in 6th INTERNATIONAL STUDENT CONFERENCE ON TECHNICAL SCIENCES. 2019;:6-6..

Pantović Spajić, Katarina, Stojanović, Ksenija, Sakan, Sanja, Đorđević, Dragana, "One-step extraction of Cd, Ni, Sb and V applied to the river and accumulation sediments located in Serbia" in 6th INTERNATIONAL STUDENT CONFERENCE ON TECHNICAL SCIENCES (2019):6-6.

TY  - CONF
AU  - Vuković, Nikola
AU  - Nytoft, Hans Peter
AU  - Stojanović, Ksenija
PY  - 2019
UR  - https://ritnms.itnms.ac.rs/handle/123456789/510
PB  - European Association of Geoscientists and Engineers, EAGE
C3  - 29th International Meeting on Organic Geochemistry, IMOG 2019
T1  - The applicability of asphaltene treatment (mild oxidation and pyrolysis) in the investigation of crude oils
DO  - 10.3997/2214-4609.201902944
UR  - conv_1019
ER  - 

@conference{
author = "Vuković, Nikola and Nytoft, Hans Peter and Stojanović, Ksenija",
year = "2019",
publisher = "European Association of Geoscientists and Engineers, EAGE",
journal = "29th International Meeting on Organic Geochemistry, IMOG 2019",
title = "The applicability of asphaltene treatment (mild oxidation and pyrolysis) in the investigation of crude oils",
doi = "10.3997/2214-4609.201902944",
url = "conv_1019"
}

Vuković, N., Nytoft, H. P.,& Stojanović, K.. (2019). The applicability of asphaltene treatment (mild oxidation and pyrolysis) in the investigation of crude oils. in 29th International Meeting on Organic Geochemistry, IMOG 2019
European Association of Geoscientists and Engineers, EAGE..
https://doi.org/10.3997/2214-4609.201902944
conv_1019

Vuković N, Nytoft HP, Stojanović K. The applicability of asphaltene treatment (mild oxidation and pyrolysis) in the investigation of crude oils. in 29th International Meeting on Organic Geochemistry, IMOG 2019. 2019;.
doi:10.3997/2214-4609.201902944
conv_1019 .

Vuković, Nikola, Nytoft, Hans Peter, Stojanović, Ksenija, "The applicability of asphaltene treatment (mild oxidation and pyrolysis) in the investigation of crude oils" in 29th International Meeting on Organic Geochemistry, IMOG 2019 (2019),
https://doi.org/10.3997/2214-4609.201902944 .,
conv_1019 .

TY  - CONF
AU  - Stevanović, Jelena
AU  - Vuković, Nikola
AU  - Stojanović, Ksenija
PY  - 2019
UR  - https://ritnms.itnms.ac.rs/handle/123456789/492
PB  - European Association of Geoscientists and Engineers, EAGE
C3  - 29th International Meeting on Organic Geochemistry, IMOG 2019
T1  - Origin of oils and source rocks characterization of the Turija-Sever oil field (SE Pannonian Basin, Serbia)
DO  - 10.3997/2214-4609.201902803
UR  - conv_1020
ER  - 

@conference{
author = "Stevanović, Jelena and Vuković, Nikola and Stojanović, Ksenija",
year = "2019",
publisher = "European Association of Geoscientists and Engineers, EAGE",
journal = "29th International Meeting on Organic Geochemistry, IMOG 2019",
title = "Origin of oils and source rocks characterization of the Turija-Sever oil field (SE Pannonian Basin, Serbia)",
doi = "10.3997/2214-4609.201902803",
url = "conv_1020"
}

Stevanović, J., Vuković, N.,& Stojanović, K.. (2019). Origin of oils and source rocks characterization of the Turija-Sever oil field (SE Pannonian Basin, Serbia). in 29th International Meeting on Organic Geochemistry, IMOG 2019
European Association of Geoscientists and Engineers, EAGE..
https://doi.org/10.3997/2214-4609.201902803
conv_1020

Stevanović J, Vuković N, Stojanović K. Origin of oils and source rocks characterization of the Turija-Sever oil field (SE Pannonian Basin, Serbia). in 29th International Meeting on Organic Geochemistry, IMOG 2019. 2019;.
doi:10.3997/2214-4609.201902803
conv_1020 .

Stevanović, Jelena, Vuković, Nikola, Stojanović, Ksenija, "Origin of oils and source rocks characterization of the Turija-Sever oil field (SE Pannonian Basin, Serbia)" in 29th International Meeting on Organic Geochemistry, IMOG 2019 (2019),
https://doi.org/10.3997/2214-4609.201902803 .,
conv_1020 .

TY  - JOUR
AU  - Pantović-Spajić, Katarina
AU  - Sakan, S.
AU  - Đorđević, D.
AU  - Šoštarić, Tatjana
AU  - Lopičić, Zorica
AU  - Janićijević, A.
AU  - Stojanović, Ksenija
PY  - 2019
UR  - https://ritnms.itnms.ac.rs/handle/123456789/505
AB  - The purpose of this paper was to investigate the effectiveness of three different extraction agents for the extraction of 25 elements from sediment samples collected from 4 artificial lakes and 12 rivers in Serbia (33 samples in total). The extraction efficiency of the agents was evaluated by its ability to extract the highest quantity of the elements. For that purpose, three acids (1M HCl, 2M HNO3 and 0.43M CH3COOH) have been used. Inductively coupled plasma atomic emission spectrometry (ICP-OES) was used for quantitative determination of following elements: Al, As, B, Ba, Be, Bi, Ca, Cd, Cr, Co, Cu, Fe, Hg, K, Li, Mg, Mn, Ni, Na, Pb, Sb, Se, Sr, V, and Zn. The extraction with 1M HCl has shown the best results for the majority of investigated elements (especially Sr, Mn and Ca). Antimony (Sb) was detected only after extraction with 0.43M CH3COOOH, while selenium (Se) could not be detected when 2M HNO3 was applied as extraction agents. The present study could be very useful for choosing a suitable method for specific elements and also can be helpful in the evaluation of the contaminants in freshwater sediments in Serbia. This might contribute to environmental risk assessment of the present elements.
PB  - Univerzitet u Novom Sadu - Tehnološki fakultet, Novi Sad
T2  - Acta Periodica Technologica
T1  - Comparison of extraction agents for metal determination in sediments from artificial lakes and rivers in Serbia
EP  - 196
SP  - 189
VL  - 50
DO  - 10.2298/APT1950189P
UR  - conv_1023
ER  - 

@article{
author = "Pantović-Spajić, Katarina and Sakan, S. and Đorđević, D. and Šoštarić, Tatjana and Lopičić, Zorica and Janićijević, A. and Stojanović, Ksenija",
year = "2019",
abstract = "The purpose of this paper was to investigate the effectiveness of three different extraction agents for the extraction of 25 elements from sediment samples collected from 4 artificial lakes and 12 rivers in Serbia (33 samples in total). The extraction efficiency of the agents was evaluated by its ability to extract the highest quantity of the elements. For that purpose, three acids (1M HCl, 2M HNO3 and 0.43M CH3COOH) have been used. Inductively coupled plasma atomic emission spectrometry (ICP-OES) was used for quantitative determination of following elements: Al, As, B, Ba, Be, Bi, Ca, Cd, Cr, Co, Cu, Fe, Hg, K, Li, Mg, Mn, Ni, Na, Pb, Sb, Se, Sr, V, and Zn. The extraction with 1M HCl has shown the best results for the majority of investigated elements (especially Sr, Mn and Ca). Antimony (Sb) was detected only after extraction with 0.43M CH3COOOH, while selenium (Se) could not be detected when 2M HNO3 was applied as extraction agents. The present study could be very useful for choosing a suitable method for specific elements and also can be helpful in the evaluation of the contaminants in freshwater sediments in Serbia. This might contribute to environmental risk assessment of the present elements.",
publisher = "Univerzitet u Novom Sadu - Tehnološki fakultet, Novi Sad",
journal = "Acta Periodica Technologica",
title = "Comparison of extraction agents for metal determination in sediments from artificial lakes and rivers in Serbia",
pages = "196-189",
volume = "50",
doi = "10.2298/APT1950189P",
url = "conv_1023"
}

Pantović-Spajić, K., Sakan, S., Đorđević, D., Šoštarić, T., Lopičić, Z., Janićijević, A.,& Stojanović, K.. (2019). Comparison of extraction agents for metal determination in sediments from artificial lakes and rivers in Serbia. in Acta Periodica Technologica
Univerzitet u Novom Sadu - Tehnološki fakultet, Novi Sad., 50, 189-196.
https://doi.org/10.2298/APT1950189P
conv_1023

Pantović-Spajić K, Sakan S, Đorđević D, Šoštarić T, Lopičić Z, Janićijević A, Stojanović K. Comparison of extraction agents for metal determination in sediments from artificial lakes and rivers in Serbia. in Acta Periodica Technologica. 2019;50:189-196.
doi:10.2298/APT1950189P
conv_1023 .

Pantović-Spajić, Katarina, Sakan, S., Đorđević, D., Šoštarić, Tatjana, Lopičić, Zorica, Janićijević, A., Stojanović, Ksenija, "Comparison of extraction agents for metal determination in sediments from artificial lakes and rivers in Serbia" in Acta Periodica Technologica, 50 (2019):189-196,
https://doi.org/10.2298/APT1950189P .,
conv_1023 .

TY  - CONF
AU  - Stojanović, Ksenija
AU  - Nytoft, Hans Peter
AU  - Kildahl-Andersen, Geir
AU  - Vuković, Nikola
PY  - 2018
UR  - https://ritnms.itnms.ac.rs/handle/123456789/823
AB  - A series of novel C33-C35 hexacyclic benzohopanes have been identified in coals and crude oils
of different ages from all over the world [1]. They differ from regular benzohopanes by the presence
of methyl group in position C-31. These compounds are more abundant in coals and terrestrial oils.
The investigation also showed that mature samples have distributions of benzohopanes distinct from
immature ones, which are characterised by a greater number of benzohopane isomers. Although exact
structures of the additional isomers were not determined, it seems they were formed by an
isomerisation of alkyl groups attached to the aromatic ring.
Two novel monoaromatic hydrocarbons (MW = 270; basic fragment ions m/z 255 and 146)
were identified in coals, mudstones and crude oils. Their structures were determined as cis- and transicetexa-
8,11,13-trienes (or dehydroicetexanes) using NMR spectroscopy. Dehydroicetexanes are
potential biomarkers of Cupressaceae (cypress conifers).
Benzo[b]naphtho[d]furans (BNFs) have been identified in oils, condensates, source-rocks,
coals and coaly shales, being more abundant in the latter. We detected BNFs (m/z 218) in relatively
high amounts in the aromatic fractions of pyrolysates of brown coals which attained the maturity
corresponding to vitrinite reflectance of 1.80 %Rr [2]. This result suggests that BNFs can be attractive
for investigations of mature fluids that originate from gas/condensate prone sources, rich in type III
kerogen, which are usually depleted in biomarkers. Recently, it was observed that [2,1]/[1,2]BNF
ratio can be used to describe lithofacies [3]. This ratio is much lower in sediments from fluvial-deltaic
systems than in clay-depleted sediments from marine environments.
1-Chloro-n-alkanes (m/z 91) have been identified in saltmarsh vegetation, recent sediments
from estuarine setting and freshwater lake sediments [4]. Despite their absence in the investigated
crude oils, we identified a series of 1-chloro-n-alkanes in pyrolysates of the corresponding
asphaltenes, obtained at 250 oC. This result indicates very good preservation of biomarkers occluded
inside asphaltenes and announces a possible application of 1-chloro-n-alkanes in correlation studies.
PB  - Tomsk : Institute of Strength Physics and Materials Science, Siberian Branch of Russian Academy of Sciences
PB  - Tomsk : Institute of Petroleum Chemistry, Siberian Branch of Russian Academy of Sciences
C3  - 10th International Conference „Oil and Gas Chemistry“
T1  - The review of some novel biomarkers in sedimentary organic matter
EP  - 673
SP  - 673
ER  - 

@conference{
author = "Stojanović, Ksenija and Nytoft, Hans Peter and Kildahl-Andersen, Geir and Vuković, Nikola",
year = "2018",
abstract = "A series of novel C33-C35 hexacyclic benzohopanes have been identified in coals and crude oils
of different ages from all over the world [1]. They differ from regular benzohopanes by the presence
of methyl group in position C-31. These compounds are more abundant in coals and terrestrial oils.
The investigation also showed that mature samples have distributions of benzohopanes distinct from
immature ones, which are characterised by a greater number of benzohopane isomers. Although exact
structures of the additional isomers were not determined, it seems they were formed by an
isomerisation of alkyl groups attached to the aromatic ring.
Two novel monoaromatic hydrocarbons (MW = 270; basic fragment ions m/z 255 and 146)
were identified in coals, mudstones and crude oils. Their structures were determined as cis- and transicetexa-
8,11,13-trienes (or dehydroicetexanes) using NMR spectroscopy. Dehydroicetexanes are
potential biomarkers of Cupressaceae (cypress conifers).
Benzo[b]naphtho[d]furans (BNFs) have been identified in oils, condensates, source-rocks,
coals and coaly shales, being more abundant in the latter. We detected BNFs (m/z 218) in relatively
high amounts in the aromatic fractions of pyrolysates of brown coals which attained the maturity
corresponding to vitrinite reflectance of 1.80 %Rr [2]. This result suggests that BNFs can be attractive
for investigations of mature fluids that originate from gas/condensate prone sources, rich in type III
kerogen, which are usually depleted in biomarkers. Recently, it was observed that [2,1]/[1,2]BNF
ratio can be used to describe lithofacies [3]. This ratio is much lower in sediments from fluvial-deltaic
systems than in clay-depleted sediments from marine environments.
1-Chloro-n-alkanes (m/z 91) have been identified in saltmarsh vegetation, recent sediments
from estuarine setting and freshwater lake sediments [4]. Despite their absence in the investigated
crude oils, we identified a series of 1-chloro-n-alkanes in pyrolysates of the corresponding
asphaltenes, obtained at 250 oC. This result indicates very good preservation of biomarkers occluded
inside asphaltenes and announces a possible application of 1-chloro-n-alkanes in correlation studies.",
publisher = "Tomsk : Institute of Strength Physics and Materials Science, Siberian Branch of Russian Academy of Sciences, Tomsk : Institute of Petroleum Chemistry, Siberian Branch of Russian Academy of Sciences",
journal = "10th International Conference „Oil and Gas Chemistry“",
title = "The review of some novel biomarkers in sedimentary organic matter",
pages = "673-673"
}

Stojanović, K., Nytoft, H. P., Kildahl-Andersen, G.,& Vuković, N.. (2018). The review of some novel biomarkers in sedimentary organic matter. in 10th International Conference „Oil and Gas Chemistry“
Tomsk : Institute of Strength Physics and Materials Science, Siberian Branch of Russian Academy of Sciences., 673-673.

Stojanović K, Nytoft HP, Kildahl-Andersen G, Vuković N. The review of some novel biomarkers in sedimentary organic matter. in 10th International Conference „Oil and Gas Chemistry“. 2018;:673-673..

Stojanović, Ksenija, Nytoft, Hans Peter, Kildahl-Andersen, Geir, Vuković, Nikola, "The review of some novel biomarkers in sedimentary organic matter" in 10th International Conference „Oil and Gas Chemistry“ (2018):673-673.

TY  - CONF
AU  - Stevanović, Jelena
AU  - Teslić, Slađana
AU  - Kharchenko, Igor
AU  - Vuković, Nikola
AU  - Stojanović, Ksenija
PY  - 2018
UR  - https://ritnms.itnms.ac.rs/handle/123456789/824
AB  - The Turija oil field, being an important oil field in Serbia, is located in the Banat Depression of
the southeastern part of the Pannonian Basin. Oil samples from the Turija oil field were investigated
in order to estimate origin, depositional environment, thermal maturity and age of the corresponding
source rocks. For that purpose, a comprehensive analysis of biomarkers and aromatic compounds was
performed.
n-Alkanes are predominant compounds in the total ion chromatograms of saturated fractions of
all samples, showing that Turija oils are not biodegraded. The distributions of n-alkanes, which are
characterised by equivalent abundances of long- and short-chain homologues and maximums at C17,
C21 and C27, suggest a mixed aquatic-terrestrial origin. The uniform distributions of regular C27-C29
5α(H)14α(H)17α(H) 20(R) steranes support the previous assumption. The presence of oleanane in all
samples is indicative for a contribution of angiosperm plants to the precursor organic matter (OM).
Furthermore, the presence of this biomarker implies the Upper Cretaceous or younger age of the
corresponding source rocks. Isoreniratane and its derivatives have been identified in all samples.
Although isorenieratane can originate from β-carotene, which is widespread in algae, bacteria and
terrestrial plants, the presence of other catagenetic products of isorenieratene (mass fragmentogram
m/z 133 of the aromatic fraction) unambiguously confirms a contribution of green sulphur bacteria
Chlorobiaceae to the precursor organic material [1].
The pristane to phytane (Pr/Ph) ratio ranges from 0.64 to 1.17, indicating reducing to dysoxic
conditions during the deposition of precursor OM. The presence of the above mentioned
isorenieratane derivatives implies the photic zone of anoxia. The stratification of water column is also
supported by the presence of gammacerane and values of gammacerane index, GI = gammacerane x
10/(gammacerane + C30 17α(H)21β(H)-hopane) > 1 in almost all the samples. Alkylated 2-methyl-2-
(4,8,12-trimethyltridecyl) chromans (MTTCs) were detected in all studied oils. A predominance of
5,7,8-trimethyl-MTTC over 5,8-dimethyl-MTTC, 7,8-dimethyl-MTTC and 8-methyl-MTTC,
associated with the values of MTTC ratio (MTTC = 5,7,8-trimethyl-MTTC/ΣMTTCs) in 0.44 to 0.65
range, indicates deposition of OM in a brackish environment [2].
The maturity of Turija oils was determined using typical sterane and hopane isomerisation
maturity parameters and methyldibenzothiophene ratio, MDBTR = 4-MDBT/1-MDBT [3]. The
obtained results indicate that Turija oils were generated in an early stage of oil window.
PB  - Tomsk : Institute of Strength Physics and Materials Science, Siberian Branch of Russian Academy of Sciences
PB  - Tomsk : Institute of Petroleum Chemistry, Siberian Branch of Russian Academy of Sciences
C3  - 10th International Conference „Oil and Gas Chemistry“
T1  - Organic geochemistry of crude oils from the Turija oil field (SE Pannonian Basin, Serbia)
EP  - 697
SP  - 697
DO  - 10.17223/9785946217408/446
ER  - 

@conference{
author = "Stevanović, Jelena and Teslić, Slađana and Kharchenko, Igor and Vuković, Nikola and Stojanović, Ksenija",
year = "2018",
abstract = "The Turija oil field, being an important oil field in Serbia, is located in the Banat Depression of
the southeastern part of the Pannonian Basin. Oil samples from the Turija oil field were investigated
in order to estimate origin, depositional environment, thermal maturity and age of the corresponding
source rocks. For that purpose, a comprehensive analysis of biomarkers and aromatic compounds was
performed.
n-Alkanes are predominant compounds in the total ion chromatograms of saturated fractions of
all samples, showing that Turija oils are not biodegraded. The distributions of n-alkanes, which are
characterised by equivalent abundances of long- and short-chain homologues and maximums at C17,
C21 and C27, suggest a mixed aquatic-terrestrial origin. The uniform distributions of regular C27-C29
5α(H)14α(H)17α(H) 20(R) steranes support the previous assumption. The presence of oleanane in all
samples is indicative for a contribution of angiosperm plants to the precursor organic matter (OM).
Furthermore, the presence of this biomarker implies the Upper Cretaceous or younger age of the
corresponding source rocks. Isoreniratane and its derivatives have been identified in all samples.
Although isorenieratane can originate from β-carotene, which is widespread in algae, bacteria and
terrestrial plants, the presence of other catagenetic products of isorenieratene (mass fragmentogram
m/z 133 of the aromatic fraction) unambiguously confirms a contribution of green sulphur bacteria
Chlorobiaceae to the precursor organic material [1].
The pristane to phytane (Pr/Ph) ratio ranges from 0.64 to 1.17, indicating reducing to dysoxic
conditions during the deposition of precursor OM. The presence of the above mentioned
isorenieratane derivatives implies the photic zone of anoxia. The stratification of water column is also
supported by the presence of gammacerane and values of gammacerane index, GI = gammacerane x
10/(gammacerane + C30 17α(H)21β(H)-hopane) > 1 in almost all the samples. Alkylated 2-methyl-2-
(4,8,12-trimethyltridecyl) chromans (MTTCs) were detected in all studied oils. A predominance of
5,7,8-trimethyl-MTTC over 5,8-dimethyl-MTTC, 7,8-dimethyl-MTTC and 8-methyl-MTTC,
associated with the values of MTTC ratio (MTTC = 5,7,8-trimethyl-MTTC/ΣMTTCs) in 0.44 to 0.65
range, indicates deposition of OM in a brackish environment [2].
The maturity of Turija oils was determined using typical sterane and hopane isomerisation
maturity parameters and methyldibenzothiophene ratio, MDBTR = 4-MDBT/1-MDBT [3]. The
obtained results indicate that Turija oils were generated in an early stage of oil window.",
publisher = "Tomsk : Institute of Strength Physics and Materials Science, Siberian Branch of Russian Academy of Sciences, Tomsk : Institute of Petroleum Chemistry, Siberian Branch of Russian Academy of Sciences",
journal = "10th International Conference „Oil and Gas Chemistry“",
title = "Organic geochemistry of crude oils from the Turija oil field (SE Pannonian Basin, Serbia)",
pages = "697-697",
doi = "10.17223/9785946217408/446"
}

Stevanović, J., Teslić, S., Kharchenko, I., Vuković, N.,& Stojanović, K.. (2018). Organic geochemistry of crude oils from the Turija oil field (SE Pannonian Basin, Serbia). in 10th International Conference „Oil and Gas Chemistry“
Tomsk : Institute of Strength Physics and Materials Science, Siberian Branch of Russian Academy of Sciences., 697-697.
https://doi.org/10.17223/9785946217408/446

Stevanović J, Teslić S, Kharchenko I, Vuković N, Stojanović K. Organic geochemistry of crude oils from the Turija oil field (SE Pannonian Basin, Serbia). in 10th International Conference „Oil and Gas Chemistry“. 2018;:697-697.
doi:10.17223/9785946217408/446 .

Stevanović, Jelena, Teslić, Slađana, Kharchenko, Igor, Vuković, Nikola, Stojanović, Ksenija, "Organic geochemistry of crude oils from the Turija oil field (SE Pannonian Basin, Serbia)" in 10th International Conference „Oil and Gas Chemistry“ (2018):697-697,
https://doi.org/10.17223/9785946217408/446 . .

TY  - JOUR
AU  - Vuković, Nikola
AU  - Životić, Dragana
AU  - Mendonca Filho, Joao Graciano
AU  - Kravić-Stevović, Tamara
AU  - Hamor-Vido, Maria
AU  - Mendonca, Joalice de Oliveira
AU  - Stojanović, Ksenija
PY  - 2016
UR  - https://ritnms.itnms.ac.rs/handle/123456789/414
AB  - The artificial maturation changes of the humic coal organic matter (OM) from late diagenesis to the semianthracite stage of coalification were investigated using the closed-system pyrolysis. Two extracted coal samples, a subbituminous coal 26C (with a random vitrinite reflectance Rr = 0.42%) and a high volatile bituminous coal 30C (Rr = 0.56%), were pyrolysed during 4 hat two different temperatures, 250 degrees C and 400 degrees C. The applied petrographic and organic geochemical analyses showed that the humic coal OM is sensitive to the artificial thermal stress. A good correlation between the changes in petrographic characteristics and the derived liquid products was observed. The contents of all vitrinite macerals, as well as total vitrinite, increased during the thermal maturation. The abundance of liptinite macerals decreased during the maturation and they practically disappeared after 4 h of the pyrolysis at 400 degrees C. The total inertinite contents increased after the pyrolysis at 250 degrees C, yet to be decreased after the pyrolysis at 400 degrees C. The content of organic carbon increased from coals to the solid residues at 400 degrees C, whereas the contents of total hydrogen and sulphur decreased. The yields of gases, liquid products and solid residues at respective temperatures were very similar for both coals, regardless of the rank. As expected, the pyrolysis at 400 degrees C gave higher gas and liquid yields than at 250 degrees C. Regarding the liquid pyrolysates, more pronounced changes were observed in the distribution of aromatic compounds than in saturated biomarkers. The distributions of the aromatics indicate that apart from cracking and isomerisation (the formation of thermodynamically more stable isomers), the reactions of dehydrocyclization, condensation (the formation of more stable conjugated systems) and aromatization, as well as reactions involving H2S, elemental sulphur and reactive phenyl radicals released during the pyrolysis, also play an important role. It was shown that bentonitic clay plays a more important role in the subsequent aromatization of the OM than the initial maturity of the coal OM. n-Alkane parameters were useful at lower maturities (up to similar to 0.75% Rr), whereas sterane, naphthalene and phenanthrene maturity ratios are applicable at higher maturities (>0.75% Rr). Hopane parameters showed variable sensitivities over the investigated maturity range (0.5-1.8% Rr). The most sensitive maturity parameters in the wide range of the humic OM maturity (0.5-1.8% Rr) are vitrinite reflectance, phenylnaphthalene ratio, methylchrysene index 2 and a parameter proposed in this study, based on the distribution of methylfluorenes (MF): (2- + 3-MF) / (1- + 4-MF). Generally, maturity parameters based solely on the isomerisation reactions of alkylaromatics, which do not include alkylation/dealkylation processes, are more appropriate for the humic OM, particularly at higher maturities.
PB  - Elsevier, Amsterdam
T2  - International Journal of Coal Geology
T1  - The assessment of maturation changes of humic coal organic matter - Insights from closed-system pyrolysis experiments
EP  - 239
SP  - 213
VL  - 154-155
DO  - 10.1016/j.coal.2016.01.007
UR  - conv_752
ER  - 

@article{
author = "Vuković, Nikola and Životić, Dragana and Mendonca Filho, Joao Graciano and Kravić-Stevović, Tamara and Hamor-Vido, Maria and Mendonca, Joalice de Oliveira and Stojanović, Ksenija",
year = "2016",
abstract = "The artificial maturation changes of the humic coal organic matter (OM) from late diagenesis to the semianthracite stage of coalification were investigated using the closed-system pyrolysis. Two extracted coal samples, a subbituminous coal 26C (with a random vitrinite reflectance Rr = 0.42%) and a high volatile bituminous coal 30C (Rr = 0.56%), were pyrolysed during 4 hat two different temperatures, 250 degrees C and 400 degrees C. The applied petrographic and organic geochemical analyses showed that the humic coal OM is sensitive to the artificial thermal stress. A good correlation between the changes in petrographic characteristics and the derived liquid products was observed. The contents of all vitrinite macerals, as well as total vitrinite, increased during the thermal maturation. The abundance of liptinite macerals decreased during the maturation and they practically disappeared after 4 h of the pyrolysis at 400 degrees C. The total inertinite contents increased after the pyrolysis at 250 degrees C, yet to be decreased after the pyrolysis at 400 degrees C. The content of organic carbon increased from coals to the solid residues at 400 degrees C, whereas the contents of total hydrogen and sulphur decreased. The yields of gases, liquid products and solid residues at respective temperatures were very similar for both coals, regardless of the rank. As expected, the pyrolysis at 400 degrees C gave higher gas and liquid yields than at 250 degrees C. Regarding the liquid pyrolysates, more pronounced changes were observed in the distribution of aromatic compounds than in saturated biomarkers. The distributions of the aromatics indicate that apart from cracking and isomerisation (the formation of thermodynamically more stable isomers), the reactions of dehydrocyclization, condensation (the formation of more stable conjugated systems) and aromatization, as well as reactions involving H2S, elemental sulphur and reactive phenyl radicals released during the pyrolysis, also play an important role. It was shown that bentonitic clay plays a more important role in the subsequent aromatization of the OM than the initial maturity of the coal OM. n-Alkane parameters were useful at lower maturities (up to similar to 0.75% Rr), whereas sterane, naphthalene and phenanthrene maturity ratios are applicable at higher maturities (>0.75% Rr). Hopane parameters showed variable sensitivities over the investigated maturity range (0.5-1.8% Rr). The most sensitive maturity parameters in the wide range of the humic OM maturity (0.5-1.8% Rr) are vitrinite reflectance, phenylnaphthalene ratio, methylchrysene index 2 and a parameter proposed in this study, based on the distribution of methylfluorenes (MF): (2- + 3-MF) / (1- + 4-MF). Generally, maturity parameters based solely on the isomerisation reactions of alkylaromatics, which do not include alkylation/dealkylation processes, are more appropriate for the humic OM, particularly at higher maturities.",
publisher = "Elsevier, Amsterdam",
journal = "International Journal of Coal Geology",
title = "The assessment of maturation changes of humic coal organic matter - Insights from closed-system pyrolysis experiments",
pages = "239-213",
volume = "154-155",
doi = "10.1016/j.coal.2016.01.007",
url = "conv_752"
}

Vuković, N., Životić, D., Mendonca Filho, J. G., Kravić-Stevović, T., Hamor-Vido, M., Mendonca, J. d. O.,& Stojanović, K.. (2016). The assessment of maturation changes of humic coal organic matter - Insights from closed-system pyrolysis experiments. in International Journal of Coal Geology
Elsevier, Amsterdam., 154-155, 213-239.
https://doi.org/10.1016/j.coal.2016.01.007
conv_752

Vuković N, Životić D, Mendonca Filho JG, Kravić-Stevović T, Hamor-Vido M, Mendonca JDO, Stojanović K. The assessment of maturation changes of humic coal organic matter - Insights from closed-system pyrolysis experiments. in International Journal of Coal Geology. 2016;154-155:213-239.
doi:10.1016/j.coal.2016.01.007
conv_752 .

Vuković, Nikola, Životić, Dragana, Mendonca Filho, Joao Graciano, Kravić-Stevović, Tamara, Hamor-Vido, Maria, Mendonca, Joalice de Oliveira, Stojanović, Ksenija, "The assessment of maturation changes of humic coal organic matter - Insights from closed-system pyrolysis experiments" in International Journal of Coal Geology, 154-155 (2016):213-239,
https://doi.org/10.1016/j.coal.2016.01.007 .,
conv_752 .

TY  - JOUR
AU  - Nytoft, H.P.
AU  - Vuković, Nikola
AU  - Kildahl-Andersen, Geir
AU  - Rise, Frode
AU  - Životić, Dragana
AU  - Stojanović, Ksenija
PY  - 2016
UR  - https://ritnms.itnms.ac.rs/handle/123456789/394
AB  - series of novel C-33-C-35 hexacyclic benzohopanes (C(33)b-C(35)b) were identified in 39 samples of coal extracts and 39 crude oils of different ages from all over the world. C(33)b and C(34)b homologues were isolated, and their structures were determined by nuclear magnetic resonance. The structure of C(35)b benzohopane was proposed based on the mass spectrum and its similarity with the mass spectra of structurally defined C(33)b and C(34)b homologues. The structures of the C(33)b-C(35)b hexacyclic benzohopanes are closely related to isohopanes; both groups are typical for terrestrial organic matter and can be useful in the correlation analysis. A possible pathway of formation of these novel benzohopanes and their hopanoid precursors with an additional branch in the aliphatic side chain is proposed. C(33)b-C(35)b hexacyclic benzohopanes are stable up to the maturity level corresponding to random vitrinite reflectance (Rr) of similar to 0.80%, which was demonstrated by analyzing the samples of different maturity and by the maturation simulation experiments: hydrous pyrolysis of two bituminous coals (Rr = 0.55 and 0.59%) and pyrolysis of an extracted bituminous coal (Rr = 0.56%) and its asphaltenes. This represents a confirmation that the formation of these novel benzohopanes is related to specific depositional conditions and microbial activity during diagenesis. Mature samples (Rr = 0.8%) and hydrous pyrolysate of the bituminous coals (Rr  LT  0.60%) obtained at 330 degrees C show a distinct distribution of benzohopanes in comparison to immature and moderately mature samples, which is characterized by a low abundance of the b series benzohopanes and the presence of regular and numerous other benzohopane isomers. The latter most likely represent isomers of regular and novel benzohopanes with different substitution patterns on the aromatic ring. This isomerization of alkyl groups attached to the aromatic ring, leading to the formation of thermodynamically more stable isomers, is a well-known maturation scenario so far reported in the series of alkylated naphthalenes, phenanthrenes, and dibenzothiophenes. Therefore, in the same way, a distribution of benzohopanes can indicate thermal maturity. In addition to the novel benzohopanes, three series (2 alpha, 2 beta, and 3 beta) of their methylated derivatives were identified in numerous samples. Finally, a novel C-35 heptacyclic benzohopane with an additional cyclopentane ring was also observed in the studied samples, and its structure was tentatively identified based on the mass spectrum. Opposite to the hexacyclic C(33)b-C(35)b benzohopanes, the formation of the C-35 heptacyclic benzohopane does not require a specific hopanoid precursor with two branches in the side chain. Therefore, this compound seems to have less geochemical significance than the new hexacyclic benzohopanes.
PB  - Amer Chemical Soc, Washington
T2  - Energy & Fuels
T1  - Identification of a Novel Series of Benzohopanes and Their Geochemical Significance
EP  - 5575
IS  - 7
SP  - 5563
VL  - 30
DO  - 10.1021/acs.energyfuels.6b00799
UR  - conv_765
ER  - 

@article{
author = "Nytoft, H.P. and Vuković, Nikola and Kildahl-Andersen, Geir and Rise, Frode and Životić, Dragana and Stojanović, Ksenija",
year = "2016",
abstract = "series of novel C-33-C-35 hexacyclic benzohopanes (C(33)b-C(35)b) were identified in 39 samples of coal extracts and 39 crude oils of different ages from all over the world. C(33)b and C(34)b homologues were isolated, and their structures were determined by nuclear magnetic resonance. The structure of C(35)b benzohopane was proposed based on the mass spectrum and its similarity with the mass spectra of structurally defined C(33)b and C(34)b homologues. The structures of the C(33)b-C(35)b hexacyclic benzohopanes are closely related to isohopanes; both groups are typical for terrestrial organic matter and can be useful in the correlation analysis. A possible pathway of formation of these novel benzohopanes and their hopanoid precursors with an additional branch in the aliphatic side chain is proposed. C(33)b-C(35)b hexacyclic benzohopanes are stable up to the maturity level corresponding to random vitrinite reflectance (Rr) of similar to 0.80%, which was demonstrated by analyzing the samples of different maturity and by the maturation simulation experiments: hydrous pyrolysis of two bituminous coals (Rr = 0.55 and 0.59%) and pyrolysis of an extracted bituminous coal (Rr = 0.56%) and its asphaltenes. This represents a confirmation that the formation of these novel benzohopanes is related to specific depositional conditions and microbial activity during diagenesis. Mature samples (Rr = 0.8%) and hydrous pyrolysate of the bituminous coals (Rr  LT  0.60%) obtained at 330 degrees C show a distinct distribution of benzohopanes in comparison to immature and moderately mature samples, which is characterized by a low abundance of the b series benzohopanes and the presence of regular and numerous other benzohopane isomers. The latter most likely represent isomers of regular and novel benzohopanes with different substitution patterns on the aromatic ring. This isomerization of alkyl groups attached to the aromatic ring, leading to the formation of thermodynamically more stable isomers, is a well-known maturation scenario so far reported in the series of alkylated naphthalenes, phenanthrenes, and dibenzothiophenes. Therefore, in the same way, a distribution of benzohopanes can indicate thermal maturity. In addition to the novel benzohopanes, three series (2 alpha, 2 beta, and 3 beta) of their methylated derivatives were identified in numerous samples. Finally, a novel C-35 heptacyclic benzohopane with an additional cyclopentane ring was also observed in the studied samples, and its structure was tentatively identified based on the mass spectrum. Opposite to the hexacyclic C(33)b-C(35)b benzohopanes, the formation of the C-35 heptacyclic benzohopane does not require a specific hopanoid precursor with two branches in the side chain. Therefore, this compound seems to have less geochemical significance than the new hexacyclic benzohopanes.",
publisher = "Amer Chemical Soc, Washington",
journal = "Energy & Fuels",
title = "Identification of a Novel Series of Benzohopanes and Their Geochemical Significance",
pages = "5575-5563",
number = "7",
volume = "30",
doi = "10.1021/acs.energyfuels.6b00799",
url = "conv_765"
}

Nytoft, H.P., Vuković, N., Kildahl-Andersen, G., Rise, F., Životić, D.,& Stojanović, K.. (2016). Identification of a Novel Series of Benzohopanes and Their Geochemical Significance. in Energy & Fuels
Amer Chemical Soc, Washington., 30(7), 5563-5575.
https://doi.org/10.1021/acs.energyfuels.6b00799
conv_765

Nytoft H, Vuković N, Kildahl-Andersen G, Rise F, Životić D, Stojanović K. Identification of a Novel Series of Benzohopanes and Their Geochemical Significance. in Energy & Fuels. 2016;30(7):5563-5575.
doi:10.1021/acs.energyfuels.6b00799
conv_765 .

Nytoft, H.P., Vuković, Nikola, Kildahl-Andersen, Geir, Rise, Frode, Životić, Dragana, Stojanović, Ksenija, "Identification of a Novel Series of Benzohopanes and Their Geochemical Significance" in Energy & Fuels, 30, no. 7 (2016):5563-5575,
https://doi.org/10.1021/acs.energyfuels.6b00799 .,
conv_765 .

TY  - CONF
AU  - Vuković, Nikola
AU  - Nytoft, Hans Peter
AU  - Životić, Dragana
AU  - Stojanović, Ksenija
PY  - 2015
UR  - https://ritnms.itnms.ac.rs/handle/123456789/1161
PB  - Stuttgart : Schweizerbart Science Publishers
C3  - 67th Annual Meeting of the International Committee for Coal and Organic Petrology
T1  - GC-MS characterization of some novel benzohopanes in coals
EP  - 163
SP  - 162
ER  - 

@conference{
author = "Vuković, Nikola and Nytoft, Hans Peter and Životić, Dragana and Stojanović, Ksenija",
year = "2015",
publisher = "Stuttgart : Schweizerbart Science Publishers",
journal = "67th Annual Meeting of the International Committee for Coal and Organic Petrology",
title = "GC-MS characterization of some novel benzohopanes in coals",
pages = "163-162"
}

Vuković, N., Nytoft, H. P., Životić, D.,& Stojanović, K.. (2015). GC-MS characterization of some novel benzohopanes in coals. in 67th Annual Meeting of the International Committee for Coal and Organic Petrology
Stuttgart : Schweizerbart Science Publishers., 162-163.

Vuković N, Nytoft HP, Životić D, Stojanović K. GC-MS characterization of some novel benzohopanes in coals. in 67th Annual Meeting of the International Committee for Coal and Organic Petrology. 2015;:162-163..

Vuković, Nikola, Nytoft, Hans Peter, Životić, Dragana, Stojanović, Ksenija, "GC-MS characterization of some novel benzohopanes in coals" in 67th Annual Meeting of the International Committee for Coal and Organic Petrology (2015):162-163.

TY  - CONF
AU  - Đoković, Nataša
AU  - Mitrović, Danica
AU  - Bechtel, Achim
AU  - Vuković, Nikola
AU  - Medić, Ana
AU  - Vuković, Nikola
AU  - Životić, Dragana
AU  - Stojanović, Ksenija
PY  - 2015
UR  - https://ritnms.itnms.ac.rs/handle/123456789/915
AB  - In present study, both lipid classes, fatty acids and neutral lipids (e.g. alcohols) were
analysed in lignite samples in order to assess organic matter source and study biogeochemical and
diagenetic alteration processes.
The choice of polar compounds as useful biomarker indicators is based on several
considerations. As lipids, fatty acids are involved in energy storage, mobilization and in
membrane structure in all living organisms, while sterols have roles in membrane function and
hormonal regulation of metabolic processes primarily only in eucaryotes [1].
Pulverised lignites were extracted by an azeotrope mixture of dichloromethane and
methanol (88:12, v:v) using a Soxhlet’s apparatus. Extracts were dissolved in a mixture of nheptane:
dichloromethane (80:1, v:v) and asphaltenes were precipitated. The heptane-soluble
organic compounds (maltenes) were separated into saturated hydrocarbons, aromatic
hydrocarbons and NSO fraction (polar fraction, which contains nitrogen, sulphur, and oxygen
compounds) using column chromatography. Portions of NSO fractions were concentrated after
which the extracts were saponified with a mixture of 6% KOH in CH3OH and distilled water (3:1,
v:v) at 80°C (pH = 14). Fatty acids (FAs) and alcohols were analysed using a method modified
from Wakeham and Beier (1991) [1]. Alcohols and FAs were extracted 3 times with n-hexane at
pH 14 and pH 1, respectively using Na2SO4 for removal of the excess water. Prior to gas
chromatography-mass spectrometry analysis (GC-MS), the FAs and alcohol fractions were
derivatised with BSTFA (N,O-bis(trimethylsilyl)trifluoroacetamide, Fluka) for 1 h at 80°C to
form trimethylsilyl esters and ethers.
The obtained results are as follows: the fatty alcohols ranging from n-C12 to n-C28 alkanols
with a high abundance of long-chain fatty alcohols (n-C22 – C28) and only trace levels of shortchain
fatty alcohols (n-C12 – C18) indicating the main terrestrial input into the system. The
monounsaturated n-C18:1 fatty alcohol, which has been found in some species of diatoms,
Skeletonema costatum [2], was also present in samples. Steroidal alcohols, β-sitosterol (5-
cholesten-24β-ethyl-3β-ol), stigmastanol (24α-ethyl-5α-cholestan-3β-ol) and cholesterol, which
are the major sterols found in higher plants, are also found in small quantities. The presence of
kauran-13-ol is in accordance with the premise of terrestrial origin, given that abietane, pimarane,
kaurane and podocarpane skeletons are produced primarily by conifer vascular plants.
n-Alcanoic acids ranging from n-C6 – C30 with a notable predominance of even chainlenghts
are present in samples, having the maximum at hexadecanoic acid (C16:0). Saturated
compounds dominate in distribution but two unsaturated fatty acids were also found, 9-
octadecanoic (C18:1) and 9-hexadecanoic acid (C16:1). Apart from fatty acids, the polar fraction contains 4,8,12,16-tetramethylheptadecan-4-olide (a fragment of chlorophyll molecule with a side
phytol chain).
Typically high concentrations of long-chain (C22 –C30) n-alkanoic acids and n-alkanols (C12
– C28) with a sharp predominance of even homologues, certain hydroxyacids and dicarboxylic
acids, diterpenoid acids, long-chain saturated alkyl (wax) esters are characteristic components of
higher vascular plant cutin and suberin [3]. Biomarker analysis of aliphatic and aromatic fraction
of lignite coal is in concordance with the results obtained in the investigation of polar compounds,
confirming that in the case of Kostolac lignite, conifer terrestrial input was dominant source of
organic matter.
PB  - Beograd : Srpsko hemijsko društvo
C3  - 7. simpozijum „Hemija i zaštita životne sredine“ sa međunarodnim učešćem (EnviroChem 2015)
T1  - Distribution of fatty acids and alcohols in lignites, from the Smederevsko Pomoravlje field, Kostolac Basin – biogeochemical approach
EP  - 228
SP  - 227
ER  - 

@conference{
author = "Đoković, Nataša and Mitrović, Danica and Bechtel, Achim and Vuković, Nikola and Medić, Ana and Vuković, Nikola and Životić, Dragana and Stojanović, Ksenija",
year = "2015",
abstract = "In present study, both lipid classes, fatty acids and neutral lipids (e.g. alcohols) were
analysed in lignite samples in order to assess organic matter source and study biogeochemical and
diagenetic alteration processes.
The choice of polar compounds as useful biomarker indicators is based on several
considerations. As lipids, fatty acids are involved in energy storage, mobilization and in
membrane structure in all living organisms, while sterols have roles in membrane function and
hormonal regulation of metabolic processes primarily only in eucaryotes [1].
Pulverised lignites were extracted by an azeotrope mixture of dichloromethane and
methanol (88:12, v:v) using a Soxhlet’s apparatus. Extracts were dissolved in a mixture of nheptane:
dichloromethane (80:1, v:v) and asphaltenes were precipitated. The heptane-soluble
organic compounds (maltenes) were separated into saturated hydrocarbons, aromatic
hydrocarbons and NSO fraction (polar fraction, which contains nitrogen, sulphur, and oxygen
compounds) using column chromatography. Portions of NSO fractions were concentrated after
which the extracts were saponified with a mixture of 6% KOH in CH3OH and distilled water (3:1,
v:v) at 80°C (pH = 14). Fatty acids (FAs) and alcohols were analysed using a method modified
from Wakeham and Beier (1991) [1]. Alcohols and FAs were extracted 3 times with n-hexane at
pH 14 and pH 1, respectively using Na2SO4 for removal of the excess water. Prior to gas
chromatography-mass spectrometry analysis (GC-MS), the FAs and alcohol fractions were
derivatised with BSTFA (N,O-bis(trimethylsilyl)trifluoroacetamide, Fluka) for 1 h at 80°C to
form trimethylsilyl esters and ethers.
The obtained results are as follows: the fatty alcohols ranging from n-C12 to n-C28 alkanols
with a high abundance of long-chain fatty alcohols (n-C22 – C28) and only trace levels of shortchain
fatty alcohols (n-C12 – C18) indicating the main terrestrial input into the system. The
monounsaturated n-C18:1 fatty alcohol, which has been found in some species of diatoms,
Skeletonema costatum [2], was also present in samples. Steroidal alcohols, β-sitosterol (5-
cholesten-24β-ethyl-3β-ol), stigmastanol (24α-ethyl-5α-cholestan-3β-ol) and cholesterol, which
are the major sterols found in higher plants, are also found in small quantities. The presence of
kauran-13-ol is in accordance with the premise of terrestrial origin, given that abietane, pimarane,
kaurane and podocarpane skeletons are produced primarily by conifer vascular plants.
n-Alcanoic acids ranging from n-C6 – C30 with a notable predominance of even chainlenghts
are present in samples, having the maximum at hexadecanoic acid (C16:0). Saturated
compounds dominate in distribution but two unsaturated fatty acids were also found, 9-
octadecanoic (C18:1) and 9-hexadecanoic acid (C16:1). Apart from fatty acids, the polar fraction contains 4,8,12,16-tetramethylheptadecan-4-olide (a fragment of chlorophyll molecule with a side
phytol chain).
Typically high concentrations of long-chain (C22 –C30) n-alkanoic acids and n-alkanols (C12
– C28) with a sharp predominance of even homologues, certain hydroxyacids and dicarboxylic
acids, diterpenoid acids, long-chain saturated alkyl (wax) esters are characteristic components of
higher vascular plant cutin and suberin [3]. Biomarker analysis of aliphatic and aromatic fraction
of lignite coal is in concordance with the results obtained in the investigation of polar compounds,
confirming that in the case of Kostolac lignite, conifer terrestrial input was dominant source of
organic matter.",
publisher = "Beograd : Srpsko hemijsko društvo",
journal = "7. simpozijum „Hemija i zaštita životne sredine“ sa međunarodnim učešćem (EnviroChem 2015)",
title = "Distribution of fatty acids and alcohols in lignites, from the Smederevsko Pomoravlje field, Kostolac Basin – biogeochemical approach",
pages = "228-227"
}

Đoković, N., Mitrović, D., Bechtel, A., Vuković, N., Medić, A., Vuković, N., Životić, D.,& Stojanović, K.. (2015). Distribution of fatty acids and alcohols in lignites, from the Smederevsko Pomoravlje field, Kostolac Basin – biogeochemical approach. in 7. simpozijum „Hemija i zaštita životne sredine“ sa međunarodnim učešćem (EnviroChem 2015)
Beograd : Srpsko hemijsko društvo., 227-228.

Đoković N, Mitrović D, Bechtel A, Vuković N, Medić A, Vuković N, Životić D, Stojanović K. Distribution of fatty acids and alcohols in lignites, from the Smederevsko Pomoravlje field, Kostolac Basin – biogeochemical approach. in 7. simpozijum „Hemija i zaštita životne sredine“ sa međunarodnim učešćem (EnviroChem 2015). 2015;:227-228..

Đoković, Nataša, Mitrović, Danica, Bechtel, Achim, Vuković, Nikola, Medić, Ana, Vuković, Nikola, Životić, Dragana, Stojanović, Ksenija, "Distribution of fatty acids and alcohols in lignites, from the Smederevsko Pomoravlje field, Kostolac Basin – biogeochemical approach" in 7. simpozijum „Hemija i zaštita životne sredine“ sa međunarodnim učešćem (EnviroChem 2015) (2015):227-228.