TY  - CONF
AU  - Kojić, I.
AU  - Kus, J.
AU  - Životić, D.
AU  - Stojanović, Ksenija A.
PY  - 2021
UR  - http://cherry.chem.bg.ac.rs/handle/123456789/5191
AB  - The organic geochemical study of Lower and Middle Miocene lignites from the coal-mining district of Lusatia in eastern Germany has been performed. Since the samples showed a uniform and low degree of maturity (0.32-0.37 %Rr), it can be considered that maturity has no significant impact on biomarker distributions. Therefore, the objective of the study is to examine the potential of biomarkers to distinguish Lower and Middle Miocene lignites in relation to sources and depositional environment of organic matter (OM). The biomarker patterns show relatively similar compositions in studied lignites, indicating no significant change in palaeclimate from Lower to Middle Miocene. Middle Miocene lignites are characterized by more pronounced variations of biomarker signatures due to the more pronounced fluctuation of water-level and/or palaeo-wildfires. Peatification was performed under stable water-level. The main differences between Middle and Lower Miocene coals are expressed by higher dehydroicetexane content, Paq index, the tetracyclic/tricyclic diterpanes ratio and non-hopanoid triterpenoids content, as well as by lower content of hopenes and fernenes in the latter one. Mentioned results indicate decreasing contribution of Cupressaceae and emergent macrophytes, associated with increased input of Pinaceae, angiosperms and ferns to the precursor OM of Middle Miocene samples in comparison to Lower Miocene samples.
PB  - European Association of Geoscientists & Engineers
C3  - Conference Proceedings, 30th International Meeting on Organic Geochemistry (IMOG 2021)
T1  - The potential of biomarkers to distinguish Lower and Middle Miocene lignites from the coal-mining district of Lusatia
VL  - 2021
DO  - 10.3997/2214-4609.202134092
ER  - 

@conference{
author = "Kojić, I. and Kus, J. and Životić, D. and Stojanović, Ksenija A.",
year = "2021",
abstract = "The organic geochemical study of Lower and Middle Miocene lignites from the coal-mining district of Lusatia in eastern Germany has been performed. Since the samples showed a uniform and low degree of maturity (0.32-0.37 %Rr), it can be considered that maturity has no significant impact on biomarker distributions. Therefore, the objective of the study is to examine the potential of biomarkers to distinguish Lower and Middle Miocene lignites in relation to sources and depositional environment of organic matter (OM). The biomarker patterns show relatively similar compositions in studied lignites, indicating no significant change in palaeclimate from Lower to Middle Miocene. Middle Miocene lignites are characterized by more pronounced variations of biomarker signatures due to the more pronounced fluctuation of water-level and/or palaeo-wildfires. Peatification was performed under stable water-level. The main differences between Middle and Lower Miocene coals are expressed by higher dehydroicetexane content, Paq index, the tetracyclic/tricyclic diterpanes ratio and non-hopanoid triterpenoids content, as well as by lower content of hopenes and fernenes in the latter one. Mentioned results indicate decreasing contribution of Cupressaceae and emergent macrophytes, associated with increased input of Pinaceae, angiosperms and ferns to the precursor OM of Middle Miocene samples in comparison to Lower Miocene samples.",
publisher = "European Association of Geoscientists & Engineers",
journal = "Conference Proceedings, 30th International Meeting on Organic Geochemistry (IMOG 2021)",
title = "The potential of biomarkers to distinguish Lower and Middle Miocene lignites from the coal-mining district of Lusatia",
volume = "2021",
doi = "10.3997/2214-4609.202134092"
}

Kojić, I., Kus, J., Životić, D.,& Stojanović, K. A.. (2021). The potential of biomarkers to distinguish Lower and Middle Miocene lignites from the coal-mining district of Lusatia. in Conference Proceedings, 30th International Meeting on Organic Geochemistry (IMOG 2021)
European Association of Geoscientists & Engineers., 2021.
https://doi.org/10.3997/2214-4609.202134092

Kojić I, Kus J, Životić D, Stojanović KA. The potential of biomarkers to distinguish Lower and Middle Miocene lignites from the coal-mining district of Lusatia. in Conference Proceedings, 30th International Meeting on Organic Geochemistry (IMOG 2021). 2021;2021.
doi:10.3997/2214-4609.202134092 .

Kojić, I., Kus, J., Životić, D., Stojanović, Ksenija A., "The potential of biomarkers to distinguish Lower and Middle Miocene lignites from the coal-mining district of Lusatia" in Conference Proceedings, 30th International Meeting on Organic Geochemistry (IMOG 2021), 2021 (2021),
https://doi.org/10.3997/2214-4609.202134092 . .

TY  - CONF
AU  - Kojić, I.
AU  - Šolević Knudsen, T.
PY  - 2021
UR  - http://cherry.chem.bg.ac.rs/handle/123456789/4918
AB  - Figure 1. Representative GC-MS chromatograms showing distribution of all PAHs analyzed in this study. The aim of this study was to investigate the origin of polycyclic aromatic hydrocarbons (PAH) in street dust samples from a small industrial city Pančevo in Serbia. The samples were collected in different parts of the city and sieved to separate the <250 µm fraction. Aromatic hydrocarbons were isolated by extraction and column chromatography. In these extracts, PAH were analysed by gas chromatography - mass spectrometry (GC/MS) using total ion current (TIC) and single ion monitoring (SIM) methods. Monitored ions were: m/z = 128 (naphthalene; N), m/z = 152 (acenaphthylene), m/z = 154 (acenaphthene), m/z = 166 (fluorene; F), m/z = 178 (phenanthrene and anthracene; P and A), m/z = 202 (fluoranthene and pyrene; Flu and Py), m/z = 228 (benzo[a]anthracene and chrysene; B[a]A and C), m/z = 252 (benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[j] fluoranthene, benzo[e]pyrene and benzo[a]pyrene; B[b]F, B[k] F, B[j]F, B[e]Py and B[a]Py), and m/z = 276 (indeno[1,2,3-c,d]pyrene and benzo[g,h,i]perylene; In- [1,2,3-cd]Py and B[ghi]Per). All these compounds were quantified (using the reference standard Z-014G PAH mix) and characteristic molecular ratios were calculated. The concentrations of non-methylated (parent) PAH in the street dust samples were found to be in the range from 175 to 2746 ppb. Content of PAHs in street dust samples is not regulated by the Serbian National legislation. However, some of these values are higher than the limit values for soils as set by Serbian National legislation [1]. All samples contain smaller amounts of lower, 2-3 ring, PAH (13 - 347 ppb), in comparison to the higher, 4-5 ring, PAH (175 - 2399 ppb) indicating pyrogenic origin of these compounds in the samples investigated [2]. Low abundance of methylated PAHs, as seen in ratio ΣMP/P (lower than 1 in all samples) indicates pyrogenic origin of these compounds. Similar conclusion can be drawn from Flu/(Flu+Py) ratio which, depending on the sample, indicates source from petroleum or biomass and coal combustion. Furthermore, PAH origin from traffic emissions, for samples collected closer to busy roads, and from biomass and coal combustion, for samples collected within residential areas, is shown by values of B[a]A/(B[a]A+C), B[a]Py/(B[a]Py+B[ghi]Per) and In[1,2,3-cd]Py/(In[1,2,3-cd]Py+B[ghi]Per ratios [3]. It can be concluded that the dominant source of PAHs in the selected street dust samples is combustion of petrol, diesel, biomass and coal which agrees with the results for similar samples in other cities in the world [2, 3].
PB  - Belgrade : Serbian Chemical Society
C3  - Book of Abstracts 21st; European Meeting on Environmental Chemistry
T1  - Preliminary Investigation of Origin of Polycyclic Aromatic Hydrocarbons in Select Street Dust Samples, Pančevo, Serbia
SP  - 126
EP  - 126
UR  - https://hdl.handle.net/21.15107/rcub_cherry_4918
ER  - 

@conference{
author = "Kojić, I. and Šolević Knudsen, T.",
year = "2021",
abstract = "Figure 1. Representative GC-MS chromatograms showing distribution of all PAHs analyzed in this study. The aim of this study was to investigate the origin of polycyclic aromatic hydrocarbons (PAH) in street dust samples from a small industrial city Pančevo in Serbia. The samples were collected in different parts of the city and sieved to separate the <250 µm fraction. Aromatic hydrocarbons were isolated by extraction and column chromatography. In these extracts, PAH were analysed by gas chromatography - mass spectrometry (GC/MS) using total ion current (TIC) and single ion monitoring (SIM) methods. Monitored ions were: m/z = 128 (naphthalene; N), m/z = 152 (acenaphthylene), m/z = 154 (acenaphthene), m/z = 166 (fluorene; F), m/z = 178 (phenanthrene and anthracene; P and A), m/z = 202 (fluoranthene and pyrene; Flu and Py), m/z = 228 (benzo[a]anthracene and chrysene; B[a]A and C), m/z = 252 (benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[j] fluoranthene, benzo[e]pyrene and benzo[a]pyrene; B[b]F, B[k] F, B[j]F, B[e]Py and B[a]Py), and m/z = 276 (indeno[1,2,3-c,d]pyrene and benzo[g,h,i]perylene; In- [1,2,3-cd]Py and B[ghi]Per). All these compounds were quantified (using the reference standard Z-014G PAH mix) and characteristic molecular ratios were calculated. The concentrations of non-methylated (parent) PAH in the street dust samples were found to be in the range from 175 to 2746 ppb. Content of PAHs in street dust samples is not regulated by the Serbian National legislation. However, some of these values are higher than the limit values for soils as set by Serbian National legislation [1]. All samples contain smaller amounts of lower, 2-3 ring, PAH (13 - 347 ppb), in comparison to the higher, 4-5 ring, PAH (175 - 2399 ppb) indicating pyrogenic origin of these compounds in the samples investigated [2]. Low abundance of methylated PAHs, as seen in ratio ΣMP/P (lower than 1 in all samples) indicates pyrogenic origin of these compounds. Similar conclusion can be drawn from Flu/(Flu+Py) ratio which, depending on the sample, indicates source from petroleum or biomass and coal combustion. Furthermore, PAH origin from traffic emissions, for samples collected closer to busy roads, and from biomass and coal combustion, for samples collected within residential areas, is shown by values of B[a]A/(B[a]A+C), B[a]Py/(B[a]Py+B[ghi]Per) and In[1,2,3-cd]Py/(In[1,2,3-cd]Py+B[ghi]Per ratios [3]. It can be concluded that the dominant source of PAHs in the selected street dust samples is combustion of petrol, diesel, biomass and coal which agrees with the results for similar samples in other cities in the world [2, 3].",
publisher = "Belgrade : Serbian Chemical Society",
journal = "Book of Abstracts 21st; European Meeting on Environmental Chemistry",
title = "Preliminary Investigation of Origin of Polycyclic Aromatic Hydrocarbons in Select Street Dust Samples, Pančevo, Serbia",
pages = "126-126",
url = "https://hdl.handle.net/21.15107/rcub_cherry_4918"
}

Kojić, I.,& Šolević Knudsen, T.. (2021). Preliminary Investigation of Origin of Polycyclic Aromatic Hydrocarbons in Select Street Dust Samples, Pančevo, Serbia. in Book of Abstracts 21st; European Meeting on Environmental Chemistry
Belgrade : Serbian Chemical Society., 126-126.
https://hdl.handle.net/21.15107/rcub_cherry_4918

Kojić I, Šolević Knudsen T. Preliminary Investigation of Origin of Polycyclic Aromatic Hydrocarbons in Select Street Dust Samples, Pančevo, Serbia. in Book of Abstracts 21st; European Meeting on Environmental Chemistry. 2021;:126-126.
https://hdl.handle.net/21.15107/rcub_cherry_4918 .

Kojić, I., Šolević Knudsen, T., "Preliminary Investigation of Origin of Polycyclic Aromatic Hydrocarbons in Select Street Dust Samples, Pančevo, Serbia" in Book of Abstracts 21st; European Meeting on Environmental Chemistry (2021):126-126,
https://hdl.handle.net/21.15107/rcub_cherry_4918 .

TY  - CONF
AU  - Kojić, I.
AU  - Šolević Knudsen, T.
PY  - 2021
UR  - http://cherry.chem.bg.ac.rs/handle/123456789/4917
AB  - The aim of this study was analysis of the origin of the aliphatic compounds in selected street dust samples. The samples were collected in the city of Pančevo, Serbia, within residential areas in close vicinity to heavy traffic roads. In order to determine if there was a significant difference in composition of aliphatic fraction depending on particle size, the samples were sieved and separated in three fractions, 500–250 µm, 250–63 µm and <63 µm. The samples were extracted, and the extracts were separated to aliphatic, aromatic and polar fractions by column chromatography. The aliphatic fractions were further analysed by GC/MS. n-alkanes were identified using mass ion m/z 71, hopanes m/z 191 and steranes m/z 217 [1]. Concentrations of total hydrocarbons in the street dust samples were in the range from 34.5 to 280.0 µg/g. It is generally accepted that total hydrocarbons content higher than 50 µg per 1g of sediment can be considered as a potential anthropogenic pollution [2]. According to these results, presence of organic pollutants in almost all samples can be presumed. Concentrations lower than 50 µg/g were observed in coarser fractions (500-250 µm). Higher concentrations of total hydrocarbons were observed in the finest fraction (< 63 µm). With only few exceptions, concentration of total hydrocarbons increases with decrease of grain size of samples indicating greater affinity of these compounds for the smallest particles. In all samples analysed, the most abundant compounds were n-alkanes, followed by n-alk-1-enes, regular isoprenoids and hopanes. No significant compositional changes were observed in different size fractions of the samples. n-Alkane distribution in all samples is bimodal, with n-alkane maximum at C20 in the range C13-C23, and with maximum at odd number n-alkanes in the range C24– C34. Carbon Preference Index (CPI) [2] for the whole range of n-alkanes (CPI C13-C33) is in the range of 1.07 – 2.40, CPI C13-C20 is close to 1, and CPI C25-C34 is in the range from 1.0 to 3.9. These results and distribution of n-alkanes in the chromatograms (Figure 1) indicate that the investigated n-alkanes in the C13-C23 range originate from a mature organic matter source while those in the C24–C34 range originate from the native terrestrial organic matter. Definite proof that the aliphatic fractions of the street dust samples contain petroleum pollutant can be seen by distributions of hopanes, steranes and diasteranes, which have typical distributions found in crude oils. It can be concluded that the aliphatic compounds in the street dust samples investigated in this study are mixtures of a natural terrestrial source (indicated by presence of even alk-1-enes and odd higher n-alkanes) and a petroleum pollutant (indicated by CPI values and presence of typical crude oil biomarkers)
PB  - Belgrade : Serbian Chemical Society
C3  - Book of Abstracts 21st; European Meeting on Environmental Chemistry
T1  - Preliminary Investigation of Origin of Aliphatic Compounds in Street Dust Samples, Pančevo, Serbia
SP  - 125
EP  - 125
UR  - https://hdl.handle.net/21.15107/rcub_cherry_4917
ER  - 

@conference{
author = "Kojić, I. and Šolević Knudsen, T.",
year = "2021",
abstract = "The aim of this study was analysis of the origin of the aliphatic compounds in selected street dust samples. The samples were collected in the city of Pančevo, Serbia, within residential areas in close vicinity to heavy traffic roads. In order to determine if there was a significant difference in composition of aliphatic fraction depending on particle size, the samples were sieved and separated in three fractions, 500–250 µm, 250–63 µm and <63 µm. The samples were extracted, and the extracts were separated to aliphatic, aromatic and polar fractions by column chromatography. The aliphatic fractions were further analysed by GC/MS. n-alkanes were identified using mass ion m/z 71, hopanes m/z 191 and steranes m/z 217 [1]. Concentrations of total hydrocarbons in the street dust samples were in the range from 34.5 to 280.0 µg/g. It is generally accepted that total hydrocarbons content higher than 50 µg per 1g of sediment can be considered as a potential anthropogenic pollution [2]. According to these results, presence of organic pollutants in almost all samples can be presumed. Concentrations lower than 50 µg/g were observed in coarser fractions (500-250 µm). Higher concentrations of total hydrocarbons were observed in the finest fraction (< 63 µm). With only few exceptions, concentration of total hydrocarbons increases with decrease of grain size of samples indicating greater affinity of these compounds for the smallest particles. In all samples analysed, the most abundant compounds were n-alkanes, followed by n-alk-1-enes, regular isoprenoids and hopanes. No significant compositional changes were observed in different size fractions of the samples. n-Alkane distribution in all samples is bimodal, with n-alkane maximum at C20 in the range C13-C23, and with maximum at odd number n-alkanes in the range C24– C34. Carbon Preference Index (CPI) [2] for the whole range of n-alkanes (CPI C13-C33) is in the range of 1.07 – 2.40, CPI C13-C20 is close to 1, and CPI C25-C34 is in the range from 1.0 to 3.9. These results and distribution of n-alkanes in the chromatograms (Figure 1) indicate that the investigated n-alkanes in the C13-C23 range originate from a mature organic matter source while those in the C24–C34 range originate from the native terrestrial organic matter. Definite proof that the aliphatic fractions of the street dust samples contain petroleum pollutant can be seen by distributions of hopanes, steranes and diasteranes, which have typical distributions found in crude oils. It can be concluded that the aliphatic compounds in the street dust samples investigated in this study are mixtures of a natural terrestrial source (indicated by presence of even alk-1-enes and odd higher n-alkanes) and a petroleum pollutant (indicated by CPI values and presence of typical crude oil biomarkers)",
publisher = "Belgrade : Serbian Chemical Society",
journal = "Book of Abstracts 21st; European Meeting on Environmental Chemistry",
title = "Preliminary Investigation of Origin of Aliphatic Compounds in Street Dust Samples, Pančevo, Serbia",
pages = "125-125",
url = "https://hdl.handle.net/21.15107/rcub_cherry_4917"
}

Kojić, I.,& Šolević Knudsen, T.. (2021). Preliminary Investigation of Origin of Aliphatic Compounds in Street Dust Samples, Pančevo, Serbia. in Book of Abstracts 21st; European Meeting on Environmental Chemistry
Belgrade : Serbian Chemical Society., 125-125.
https://hdl.handle.net/21.15107/rcub_cherry_4917

Kojić I, Šolević Knudsen T. Preliminary Investigation of Origin of Aliphatic Compounds in Street Dust Samples, Pančevo, Serbia. in Book of Abstracts 21st; European Meeting on Environmental Chemistry. 2021;:125-125.
https://hdl.handle.net/21.15107/rcub_cherry_4917 .

Kojić, I., Šolević Knudsen, T., "Preliminary Investigation of Origin of Aliphatic Compounds in Street Dust Samples, Pančevo, Serbia" in Book of Abstracts 21st; European Meeting on Environmental Chemistry (2021):125-125,
https://hdl.handle.net/21.15107/rcub_cherry_4917 .

TY  - CONF
AU  - Stojanović, Ksenija A.
AU  - Kojić, I.
PY  - 2020
UR  - http://cherry.chem.bg.ac.rs/handle/123456789/5188
PB  - Institute of Petroleum Chemistry SB RAS
C3  - 11th International Conference “Oil and Gas Chemistry”, Tomsk, Russia, September 28- October 2, 2020. Proceedings
T1  - Thermal recycling of high density polyethylene and polypropylene old/new challenge during COVID-19 pandemic
SP  - 16
UR  - https://hdl.handle.net/21.15107/rcub_cherry_5188
ER  - 

@conference{
author = "Stojanović, Ksenija A. and Kojić, I.",
year = "2020",
publisher = "Institute of Petroleum Chemistry SB RAS",
journal = "11th International Conference “Oil and Gas Chemistry”, Tomsk, Russia, September 28- October 2, 2020. Proceedings",
title = "Thermal recycling of high density polyethylene and polypropylene old/new challenge during COVID-19 pandemic",
pages = "16",
url = "https://hdl.handle.net/21.15107/rcub_cherry_5188"
}

Stojanović, K. A.,& Kojić, I.. (2020). Thermal recycling of high density polyethylene and polypropylene old/new challenge during COVID-19 pandemic. in 11th International Conference “Oil and Gas Chemistry”, Tomsk, Russia, September 28- October 2, 2020. Proceedings
Institute of Petroleum Chemistry SB RAS., 16.
https://hdl.handle.net/21.15107/rcub_cherry_5188

Stojanović KA, Kojić I. Thermal recycling of high density polyethylene and polypropylene old/new challenge during COVID-19 pandemic. in 11th International Conference “Oil and Gas Chemistry”, Tomsk, Russia, September 28- October 2, 2020. Proceedings. 2020;:16.
https://hdl.handle.net/21.15107/rcub_cherry_5188 .

Stojanović, Ksenija A., Kojić, I., "Thermal recycling of high density polyethylene and polypropylene old/new challenge during COVID-19 pandemic" in 11th International Conference “Oil and Gas Chemistry”, Tomsk, Russia, September 28- October 2, 2020. Proceedings (2020):16,
https://hdl.handle.net/21.15107/rcub_cherry_5188 .

TY  - CONF
AU  - Kojić, I.
AU  - Bechtel, A.
AU  - Sachsenhofer, R.F.
AU  - Životić, D.
AU  - Stojanović, Ksenija A.
PY  - 2019
UR  - http://cherry.chem.bg.ac.rs/handle/123456789/5173
AB  - Maturation and isotopic changes of individual hydrocarbons in lignite lithotypes through diagenesis and early catagenesis were studied. The maturity ratios based on biomarkers and alkylaromatics which showed the best applicability were determined. Intensity of observed changes of maturity ratios decreases in the following order: mineral-rich coal > matrix coal > xylite-rich coal, indicating that mineral matter, which is dominated by clays in all lithotypes, plays an important role in the isomerisation of polycyclic biomarkers and aromatic compounds. Carbon isotopic signatures of n-C25 and n-C27 alkanes, as well as δ13C values of phenathrene and cadalene are very close in studied range of maturity, confirming that isotopic signatures are useful tracers for alteration products of biological molecules. Long-chain homologues of n-alkanes exhibit slight enrichment in 12C with increasing maturity, whereas almost no change is detected in δ13C of short-chain n-alkanes. Negligible enrichment in 13C of aromatic compounds is observed during maturation.
PB  - European Association of Geoscientists & Engineers
C3  - Conference Proceedings, 29th International Meeting on Organic Geochemistry
T1  - Maturation and isotopic changes of individual hydrocarbons in lignite lithotypes through diagenesis and early catagenesis
VL  - 2019
DO  - 10.3997/2214-4609.201903023
ER  - 

@conference{
author = "Kojić, I. and Bechtel, A. and Sachsenhofer, R.F. and Životić, D. and Stojanović, Ksenija A.",
year = "2019",
abstract = "Maturation and isotopic changes of individual hydrocarbons in lignite lithotypes through diagenesis and early catagenesis were studied. The maturity ratios based on biomarkers and alkylaromatics which showed the best applicability were determined. Intensity of observed changes of maturity ratios decreases in the following order: mineral-rich coal > matrix coal > xylite-rich coal, indicating that mineral matter, which is dominated by clays in all lithotypes, plays an important role in the isomerisation of polycyclic biomarkers and aromatic compounds. Carbon isotopic signatures of n-C25 and n-C27 alkanes, as well as δ13C values of phenathrene and cadalene are very close in studied range of maturity, confirming that isotopic signatures are useful tracers for alteration products of biological molecules. Long-chain homologues of n-alkanes exhibit slight enrichment in 12C with increasing maturity, whereas almost no change is detected in δ13C of short-chain n-alkanes. Negligible enrichment in 13C of aromatic compounds is observed during maturation.",
publisher = "European Association of Geoscientists & Engineers",
journal = "Conference Proceedings, 29th International Meeting on Organic Geochemistry",
title = "Maturation and isotopic changes of individual hydrocarbons in lignite lithotypes through diagenesis and early catagenesis",
volume = "2019",
doi = "10.3997/2214-4609.201903023"
}

Kojić, I., Bechtel, A., Sachsenhofer, R.F., Životić, D.,& Stojanović, K. A.. (2019). Maturation and isotopic changes of individual hydrocarbons in lignite lithotypes through diagenesis and early catagenesis. in Conference Proceedings, 29th International Meeting on Organic Geochemistry
European Association of Geoscientists & Engineers., 2019.
https://doi.org/10.3997/2214-4609.201903023

Kojić I, Bechtel A, Sachsenhofer R, Životić D, Stojanović KA. Maturation and isotopic changes of individual hydrocarbons in lignite lithotypes through diagenesis and early catagenesis. in Conference Proceedings, 29th International Meeting on Organic Geochemistry. 2019;2019.
doi:10.3997/2214-4609.201903023 .

Kojić, I., Bechtel, A., Sachsenhofer, R.F., Životić, D., Stojanović, Ksenija A., "Maturation and isotopic changes of individual hydrocarbons in lignite lithotypes through diagenesis and early catagenesis" in Conference Proceedings, 29th International Meeting on Organic Geochemistry, 2019 (2019),
https://doi.org/10.3997/2214-4609.201903023 . .