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Separation and Molecular Characterization of Ketones in a Low Temperature Coal Tar Xiu Chen, Chunming Xu, Weilai Zhang, Chao Ma, Xuxia Liu, Suoqi Zhao, and Quan Shi Energy Fuels, Just Accepted Manuscript • DOI: 10.1021/acs.energyfuels.7b03630 • Publication Date (Web): 02 Mar 2018 Downloaded from http://pubs.acs.org on March 3, 2018
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Separation and Molecular Characterization of Ketones in a Low Temperature Coal Tar Xiu Chen, Chunming Xu, Weilai Zhang, Chao Ma, Xuxia Liu, Suoqi Zhao, Quan Shi* State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249, China
ABSTRACT Ketones are major oxygen-containing compounds in low temperature coal tars (LTCT), however, the molecular composition of these compounds is not well characterized due to the complexity of itself and the interference of the coal tar matrix. In this study, ketones were separated from a LTCT and characterized by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), Orbitrap mass spectrometry (Orbitrap MS), and gas chromatography-mass spectrometry (GC-MS). Isolation of ketones was carried out by a chemical derivatization process with Girard T reagent and followed by a hydrolysis process of the derivatives. The Girard T reagent reacted with ketones under weakly acidic conditions and introduced a charged quaternary ammonium moiety on the carbonyl to form water-soluble hydrazones, which can be separated from complex matrix through an extrography separation and have strong response in positive ion electrospray (ESI) ionization source for mass spectrometric analysis. The isolated derivatives were reversibly turned into the original ketones to selectively separate long alkyl ketones from aromatic ketones with alkyl substituents of C0-C4. The ketones were assigned to 12 class species by high resolution MS analysis: O1-5 (refers there are 1-5 oxygen atoms in the molecules), O1S1, N1O1-4, and N2O1-2, among which O1 class species was the most abundant. The long chain alkyl ketones such as aliphatic 2-, 3-, 4- ketones, alkylcyclopentanones, alkyl phenyl ketones, and aromatic ketones (such as indanone, cyclopentenone, tetralone, acetonaphthone, dihydro-phenanthrenone, benzophenone, fluorenone, fluorenyl formaldehyde, anthrone, anthracene formaldehyde, acetylanthracene,
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acetylphenanthrene, acetylfluorene, benzofluorenone et al.) were detected by GC-MS. In addition, C18-isoprenoid methyl ketone and tricyclic terpenoids and steroids with one or two oxygen atoms were found in the coal tar.
1． ．INTRODUCTION Low-temperature coal tar (LTCT) is a byproduct of coal carbonization and gasification. With the increasing consumption and the rising demands of petroleum resources, LTCT as a new alternative fuel, has great prospects in the future1. Meanwhile, LTCT also could be used to produce chemicals, for example, to separate phenols. The composition of LTCT is extremely complex: it consists of thousands of hydrocarbons and heteroatom compounds, including aliphatic2-4 and aromatic5, hydrocarbons,
phenols,7-9
nitrogen
compounds,10-12
etc..
6
Oxygen-containing
compounds, such as phenolic compounds are much more abundant in LTCT than petroleum
and
high
temperature
coal
tars.
Ketones
are
another
major
oxygen-containing compounds found in LTCT,13 while the molecular composition of these compounds was not well characterized. Moreover, ketones have negative effect on fuel storage stability for their reactivity.14-18 They can enter acid or base catalyzed condensation reactions, and additions across the C=O double bond are numerous in organic chemistry, including those with hydroperoxides.19, 20 Previous studies have been reported a variety of methods for the separation and characterization of ketones from fossil fuels. The extrography was used for the separation of ketones, and a large number of aliphatic and aromatic ketones were detected in a LTCT.13 The procedure was not commendable to separate ketones with high purity because there also exist nitriles, phenols and other hetero-atom compounds. Thin layer chromatography21,
22
also had such a problem. The most
commonly used method for separating ketones was liquid chromatography, which had a wide range of applications and was used in Colorado shale oil,23 West Siberian oil,24-26 coal extract, and the Lake Holzmaar sediment extract.27 A solid phase extraction (SPE) was specialized in the fractionation of ketones according to functional groups and applied to Irati oil shale.28 The C18 SPE cartridge was used to ACS Paragon Plus Environment
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separate fluorenone fractions (also containing alkyl-phenols and alkyl-carbazoles) in crude oils and reservoir core extracts.29 Anion-exchange polarity-based was also performed on the separation of ketones,30 but it cannot separate ketones completely from acids and hydrocarbons. A successful approach was using chemical derivatization followed by hydrolysis.31 The method was applied to the isolation of carbonyl compounds in a shale oil and a large number of ketones were detected.31 However, a large portion of the ketones cannot be identified by the gas chromatography- mass spectrometry (GC-MS) analysis. GC and/or GC- MS have been widely used for the characterization of ketones from fossil fuels.22, 26, 28, 29, 31-36 However, The GC is not applicable to the analysis of nonvolatile compounds and it lacks enough resolution capability to separate each individual compound. Recently, high resolution mass spectrometries were used for the molecular characterization of fossil fuels. ESI coupled with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS)37-39 or Orbitrap mass spectrometry (Orbitrap MS)40-43 provided molecular composition details of super-complex mixtures. ESI is an effective approach to ionize polar compounds for complex matrix. It can also ionize the weak-polar and/or nonpolar compounds with HCOONH4 as an ionization promoter.44 Alhassan et al.20 derived ketones in fossil fuels to a positively charged compounds with Girard T, which can be detected directly by ESI coupled with Orbitrap MS. Moreover, the derivatives are strong-polar water-soluble hydrazones31, which can be easily separated from complex matrix. Since ketone derivatives can be converted into ketones by hydrolysis procedure,31 it is feasible to separate ketones from coal tar and comprehensively analyzed by GC-MS and ESI MS. In this paper, we applied the methods of chemical derivatization with Girard T and hydrolysis of derivatives to separate ketones from a LTCT. GC-MS, FT-ICR MS, and Orbitrap MS were used for the molecular characterization of ketones in the coal tar and its fractions.
2. EXPERIMENTAL SECTION ACS Paragon Plus Environment
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2.1 Materials The low temperature coal tar was obtained from a commercial Lurgi lignite gasification plant. The properties and molecular composition of this sample have been well characterized previously and ketones were found abundant in a subfraction of the neutral fraction2, 13, 45, 46. In this study, the neutral fraction of the coal tar was obtained by acid/basic liquid extraction which has been described elsewhere,46 and used to separate ketones. The yield of the neutral fraction is 69.9 wt% of the total coal tar. Table 1 shows the elemental compositions of the low temperature coal tar and its neutral fraction.
Table 1 Elemental compositions of the coal tar and the neutral fraction. Elemental Compositions wt%*
C
H
O
N
S
Total
Coal Tar
85.02
8.98
4.37
0.67
0.33
99.37
Neutral Fraction
85.37
9.06
4.14
0.58
0.27
99.42
*multi methods was used for the elemental analysis: carbon and hydrogen was by ASTM D5291-2002; sulfur was by ASTM D5453-2004; oxygen was by ASTM D5622-1995 and nitrogen was by ASTM D5762-2002.
2.2 Derivatization of the Neutral Fraction with the Girard T Reagent A sketch map for the separation of ketones from the LTCT is shown in Figure 1. Figure 2 shows the reaction schemes of ketones with Girard T reagent and the hydrolysis of the derivatives. About 100 mg LTCT neutral fraction was dissolved in 2 mL dichloromethane and methanol (1:1, v/v) mixture in a 12 mL sealed vial. A total of 200 mg Girard T reagent and 60 mg acid catalyst (Amberlite IRC-50 ion-exchange resin) were added. The mixture was magnetically stirred at 40 °C for 12 h, the products were subjected to mass spectrometry analysis and further separation.
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O 100 mg neutral fraction
R2(R4)
(R3)R1
Derivatize with Girard T reagent in 2 ml DCM / MeOH (1:1,v/v), Amberlite IRC-50 ion-exchange resin as the acid catalyst, derivatization
Derivatized sample Remove the solvent, add 2 ml DCM, add 0.3 g silica gel, remove DCM after mixing
O R1(R3) R2(R4)
Cl
N
N
Derivatized sample loaded silica gel
N H
Packed in a glass column containing 0.5 g alkali modified silica gel and 2 g silica gel Extrography column Eluted successively Hexane 45 ml Toluene 50 ml
DCM / MeOH (9:1, v/v) 50 ml; DCM / MeOH (3:2 , v/v) 40 ml
DCM 40 ml
F1
F2
F3
Extrography column Eluted successively
DCM / MeOH (11:1, v/v) 20 ml SF1
SF2
Cl
N
N
Derivatives dissolved in dichloromethane
N H
R2(R4)
SF3
Remove the solvent, and then add 5 ml dichloromethane
O R1(R3)
DCM / MeOH (9:1 , v/v) 30 ml; DCM / MeOH (1:2 , v/v) 30 ml DCM / MeOH (3:2 , v/v) 30 ml
Extract with 6 ml water 2 times
O
O R3 R4
N
Cl N H
N
Aqueous phase
Organic phase
Add 15 ml dichloromethane and 10 wt% HCl to pH=1-2, then hydrolyze at 30 ºC for 12 h
R1
R2
Remove dichloromethane
O Aqueous phase
Organic phase
R1
R2
Remove dichloromethane
O R3
K1
R4
K2
Figure 1 Sketch map of the separation of ketones in LTCT. (R1 and R2 are alkyl benzene or aliphatic chains; R3 and R4 have an aromatic moiety with two or more aromatic rings.)
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O
O NH2
(R3)R1
R2(R4)
Cl N H
N
DCM:MeOH(1:1 v/v)， Ion-exchange resin pH=5-7, 40ºC -H2O
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O R1(R3)
O
Girard T Derivatives
N
N H
R2
R1 O
R3
Cl
N
N
Hydrochloric acid pH=1-2, 30ºC
N H
R4
O
High-purity water
Cl
N
N
N H
R2(R4)
Girard T Reagent
R1
Cl
N
O R3
Girard T Derivatives
R2
R4
Ketone fraction
Figure. 2 Reaction schemes of ketones with Girard T reagent and the hydrolysis of the derivatives. (R1 and R2 are alkyl benzene or aliphatic chains; R3 and R4 have a aromatic moiety with two or more aromatic rings.)
2.3 Separation of GirT Derivatives from the Matrix Alkali modified silica gel (100-200 mesh) was prepared by treating 30 g silica with 60 mL of a solution of 5% potassium hydroxide in isopropanol. The solvent was removed by Soxhlet extraction with dichloromethane for 1 h. The silica gel was activated at 120 °C for 3 h, followed by deactivation by adding 3 wt % water. About 0.3 g deactivated silica gel was added to the derivatization product (obtained in 2.2). The solvent was removed under nitrogen atmosphere at 60 °C. The solid was then placed in a glass column, which was filled with 2 g deactivated silica gel and 0.5 g alkali modified silica gel on top. Another 0.5 g deactivated silica gel was placed on the top of the mixture. Hexane, toluene, dichloromethane, and mixtures of dichloromethane/methanol at ratios of 9:1, 3:2 (v/v) were used as mobile phases to elute components from the column. The Gir T derivatives of ketones were enriched in F3 fraction (mixture of dichloromethane/methanol 9:1 and 3:2 (v/v) fractions). However, the efficiency of the extrography separation is not very high, there are still some nitrogen-containing compounds in F3 fraction. In order to ensure the high purity of Gir T derivatives, F3 fraction was purified through the same extrographic steps. ACS Paragon Plus Environment
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The
Gir
T
derivatives
dichloromethane/methanol
were 9:1
and
then 3:2
enriched (v/v)
in
SF2
subfractions)
(mixture and
of SF3
(dichloromethane/methanol 1:2 (v/v) subfraction) subfractions. The solvent in these extragraphic subfractions was removed by rotary evaporation. The subfractions were then subjected to mass spectrometry. 2.4 Separation of Ketone Fractions from the LTCT GirT derivatives were processed by a hydrolysis procedure to release ketones from the oil-free derivatization product and the ketones were separated by solvent extraction. The method was modified from that reported by Harvey et al..31 The enriched GirT derivatives (SF2 subfraction) was dissolved in 5 mL dichloromethane, and then extracted by 6 mL water for 2 times to yield an aqueous phase (by combination of two extraction) and an organic phase. The solvent in organic phase was removed under a gentle stream of nitrogen to obtain the ketone fraction K1. The aqueous phase acidified with 10 wt% hydrochloric acid to pH=1-2, and then magnetically stirred at 30 °C for 12 h. The GirT derivatives then hydrolyzed and were extracted by 15 mL dichloromethane to yield the ketone fraction K2. Excessive acid was removed by washing with 15 mL water for 3 times. The solvent was removed under a gentle stream of nitrogen. The two ketone fractions were then characterized by gas chromatography-mass spectrometry (GC-MS) and Orbitrap mass spectrometry. 2.5 GC-MS Analysis The GC-MS analysis was carried out on an Agilent 7890-5975c GC-MS equipped with a HP-5 MS column (60 m × 0.25 mm × 0.25 µm). The GC oven was held at 60 °C for 3 min, programmed to 310 °C at a rate of 4 °C/min, and then held constant at 310 °C for 20 min. The injector and transfer line temperatures were held at 300 and 280 °C, respectively. Helium was used as a carrier gas at a flowing rate of 1 mL/min. The MS ion source was at 230 °C. The MS ionizing voltage was 70 eV, and the mass range was 35-500 with a 0.5 s scan period. 2.6 +ESI FT-ICR MS and Orbitrap MS Analysis
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The GirT derivatives and its hydrolyzates (K1 and K2) to be analyzed were respectively dissolved in dichloromethane/methanol (1:1, v/v) and dichloromethane to 10 mg/mL. A total of 20 µL of the sample solution was further diluted with 1 mL of toluene/methanol (1:3, v/v) solution. The GirT derivativeswere subjected to +ESI FT-ICR MS analysis without spiking with formic acid or further treatment. Ammonium formate was added to K1 and K2 to ensure efficient ionization of ketones in positive-ion ESI Orbitrap MS analysis.44 The GirT derivatives were analyzed using a Bruker apex-ultra FT-ICR mass spectrometer equipped with a 9.4 T superconducting magnet. Sample solutions were infused via an Apollo II electrospray source at 180 µL/h with a syringe pump. The positive-ion ESI operating conditions were as follows: The emitter voltage was 4.5 kV. The capillary column front end voltage was 5 kV. The capillary column end voltage was 280 V. The collision cell accumulated time was 0.6 s, and the time-of-flight window was 0.9 ms. ICR were operated at 17.00 db attenuation. The mass range was set at m/z 100−800. The data size was set to 4 M words. A total of 64 scans were accumulated. Methodologies for FT-ICR MS mass calibration, data acquisition, and processing were reported elsewhere.20, 47 K1 and K2 were analyzed through a Thermo Scientific Orbitrap Fusion mass spectrometer. The positive-ion ESI operating conditions were as follows: spray voltage, 3400 V; sheath gas (nitrogen) flow rate, 8.0 (arbitrary units); aux gas flow rate, 3.0 (arbitrary units); ion transfer tube temperature, 280 °C. The resolution was up to 500,000 at m/z 200. The scanning mass range was 100-600 Da, and the spectrum was scanned for 2 min. Thermo Xcalibur Quan Browser software was used for the qualitative analysis.
3. RESULTS AND DISCUSSION 3.1 Molecular composition of ketones in the coal tar characterized by Gir-T derivatization followed by +ESI FT-ICR MS Ketones have medium molecular polarity and can be ionized by +ESI ionization, however, these compounds present in coal tar as well as other fossil fuels cannot be ACS Paragon Plus Environment
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well characterized by +ESI MS because of the presence of the complex matrix such as sulfur-, nitrogen-, and other oxygen-containing compounds. Andersson et at.20 developed a derivatization method for the analysis of ketones in fossil fuels. Ketones reacted with Girard T reagent under weakly acidic conditions and introduced a charged quaternary ammonium moiety into the carbonyl which leading to an enhanced sensitivity in positive ESI. Ketone model compounds with different structures were investigated for the derivatization. The derivatization conversion ratio were more than 97% except 2,2,6-trimethylcyclohexanone, which has structure with large steric hindrance.20 Figure 3 shows the positive ion ESI FT-ICR MS spectrum of GirT derivatives of the coal tar (a) and the relative abundance of its corresponding ketones without Gir-T derivatization (b). The ketone classes of the coal tar include: O1-5, O1S1, and N1O1-3, corresponding to N3O1-5, N3O1S1, and N4O1-3 GirT derivatives of the mass spectrum respectively. The O1 (corresponding to N3O1 class species of GirT derivatives) ketone class species was the most abundant, followed by the O2, O3 and N1O1 class species. The relative ion abundance of DBE versus carbon number for O1 class species was shown in Figure 3 (c). The O1 class species has a wide DBE value ranges (1−18), in which the DBE values of 1-6 were most abundant. The possible core structure of O1 class species will be discussed in detail later. The relative ion abundance of DBE versus carbon number for other ketone class species was shown in Supporting Information Figure S1 and the possible structure of higher relative abundance of ketones were also shown.
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a
C18H38N3O1 C25H38N3O2 C16H34N3O1
C20H42N3O1
C13H24N3O1
C22H46N3O1
C9H20N3O1
150
200
C26H54N3O1 C30H62N3O1
250
300
350
400
450
500
1 7 13
m/z
b
DBE 2 8 14
3 9 15
4 10 16
5 11 17
6 12 18
DBE=4
O1
DBE
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
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O1S1
22 20 18 16 14 12 10 8 6 4 2 0
O2
O1
O3
O4
O5
N1O1 N1O2 N1O3
c
N3O1
O R1
R
0
5
10
15
20
25
30
35
40
Carbon Number
Figure. 3 Broad bound +ESI FT-ICR mass spectrum of the GirT derivatives of the coal tar (a); the relative abundance of its corresponding ketones without Gir-T derivatization (b) and the distribution of DBE versus carbon number for O1 class species (c).
3.2 Composition of ketones separated from the coal tar characterized by GC-MS and +ESI Orbitrap MS GirT derivatives of ketones were water-soluble hydrazones, which could be easily separated from organic compounds through water extraction.31 The products can reversibly turn into the original ketones under strongly acidic conditions through hydrolysis reaction. However, in our experiment, we found that there were a large
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amount of aliphatic ketones, alkylcyclopentanones and alkyl phenyl ketones were presented in the organic phase (DCM solution) after water extraction, and the ketones could not be completely separated from other organic compounds. The separation of GirT derivatives through water extraction could result in the loss of a portion of ketones such as aliphatic ketones, alkylcyclopentanones and alkyl phenyl ketones. In order to avoid this problem, we used extrographic fractionation for separating these compounds from the coal tar. The results (not shown) indicated that GirT derivatives were nearly completely separated from nitrogen-containing and other heteroatom compounds. The relative abundance of ketone class species from its enriched GirT derivatives was shown in Figure S2 (See Supporting Information). It should be noted that through the two extrography procedure, some aliphatic ketones with carbon number less than 18 were lost to a certain degree, but this did not affect our subsequent separation and analysis. The GirT derivatives of ketone model compounds were subjected to hydrolysis reaction according to 2.4 to obtain K1 and K2 fractions, and the result (see Supporting Information Figure S3) showed that the long alkyl ketones were mainly enriched in K1, whereas the aromatic ketones were mainly enriched in K2. This result is different from Harvey’s,31 in which the aliphatic and aromatic ketones were all enriched in one fraction. No mass peaks of GirT derivatives were found in the +ESI FT-ICR mass spectrum of the remaining water phase after hydrolysis procedure (see Supporting Information Figure S4), indicating that the conversion of the hydrolysis procedure was high. Figure 4 shows the total ion and mass chromatograms of K1 fraction of the coal tar by GC-MS. Mass chromatograms of m/z 58, 72, 84, and 105 show the distribution of aliphatic methyl ketones, 3-alkanones, alkylcyclopentanones, and alkyl phenyl ketones, respectively.13, 33, 48-50 Aliphatic methyl ketones with 12-31 carbon numbers were the most abundant compounds in K1 whereas 3-alkanones with 15-30 carbon numbers were detected with low abundance; 4-, 5-(and higher) alkanones were also detected but in trace amount. There was a clear odd carbon number predominance of aliphatic 2-ketones, especially that in the carbon number range of 21-29, in which C25 ACS Paragon Plus Environment
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showed the largest relative abundance. The homologs > C25 with a high odd carbon number predominance can be interpreted as the oxidation of vegetation wax.22 The lower abundance of the carbon number less than 15 may probably be due to their low boiling point to induce volatilization and/or the loss of their GirT derivatives during the
extrography
procedure.
The
C18
isoprene
methyl
ketone
(6,10,14-trimethylpentadecan-2-one) was also detected in this fraction, and such compounds has been found in oil shale, bitumens, and marine sediments.35, 51, 52 The C7-C26 alkyl-substituted cyclopentanones and C3-C12 alkyl phenones also exhibited a relatively high abundance. These compounds have been found in coal tars and shale oils.13, 31 The polarity of the ketones containing long alkyl chains is relatively weak, leading to the enrichment in K1. Acetonaphthone and its C1 alkyl substituents were also detected in K1 fraction, however they had relatively low abundance. The results indicate that the GirT derivatives of ketones with low molecular condensation degree are easily hydrolyzed even in neutral aqueous solution.
C25
m/z=58 C12-C31 2-Ketone
C17
C15
m/z=72 C15-C30 3-Ketone
m/z=84 2-n-Alkyl-cyclopentanones Alkyl=C7-C26 C C10
C8
m/z=105 C3-C12 Alkyl Phenone C3
C4
C6
C5
20
25
R
C29 C30 C31
C19
C23
C21
C25
C21
R
C27
C29 C30 O
C23
R
11
C12
C14
C19
C17
C25 C26 O
C7
C9
35
R
C10
C12 C20 2-Ketone C25 2-Ketone
C14 2-Ketone
30
C19
C17
C7 Phenone
K1 TIC MS
O
O
C15
C7
C27
C23
i-C18
C13
C12
C21
40
C17 2-Ketone C29 2-Ketone
45 50 Time (min)
55
Figure 4 Total ion and mass chromatograms of K1 by GC-MS.
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60
65
70
75
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Figure 5 shows the total ion chromatogram of K2 fraction of the coal tar by GC-MS. According to the references and the matching of mass spectra with the NIST library, hundreds of aromatic ketones were identified by the mass chromatogram. Some mass spectra of the ketones were shown in Figure S5 (see Supporting Information). The ketones have 2-4 aromatic rings with alkyl substituents of C0-C4, in which indanones were the most abundant. Other aromatic ketones such as tetralones, acetonaphthones, dihydro-phenanthrenones, benzophenones, fluorenones, fluorenyl formaldehydes,
anthrones,
anthracene
formaldehydes,
acetylanthracenes,
acetylphenanthrenes, acetylfluorenes, and benzofluorenones were also identified by GC-MS. Indanones and acetonaphthones have been identified in coal tar,13 and cyclopentenones, tetralones, fluorenones, benzofluorenones have also been found in other fossil fuels such as bio-oil,53 shale oil,21, 28, 31, 34 crude oil,26, 29, 54 and oil sand bitumens.55, 56 Several tricyclic diterpenoids (marked with K and J in Figure 5) and steroid ketones (marked with F) were tentatively identified in the coal tar by extracting the characteristic mass fragment m/z 300, 298, and 288, respectively. Mass spectra of compounds F and J were shown in Figure S6 (see Supporting Information). The Sugiol (marked with K), which showed high relative abundance in Figure 5, was an biomarker from a variety of higher plants,57-59 and widely present in a variety of diagenetic environments. These tricyclic diterpenoid and steroid ketones were likely to be derived from coal in diagenetic environments and chemical stable in the coal gasification process.
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O
O O
A
O O
O
C1
F C3
C2
O
O
O
B
G
O
O C1
C4
O O
O
I
C
O
O
O
A
D
O
H
B
C
E B
O
OH
H F
O O
G
J
O
D
E
OH
K
II
H
J
O
O
20
25
30
35
40
45
50
55
60
65
70
Time (min)
Figure 5 Total ion chromatogram of K2 by GC-MS. Compound assignment was carried out based on mass spectrum and GC retention time/index. Most structures were tentatively proposed, not a chemical identification.
As shown in Figure 4 and 5, although hundreds of ketones were detected by GC-MS, the humps in the chromatograms indicate that a large amount of components cannot be resolved by the chromatography. In addition, some compounds with poor volatility could not be eluted through the GC column and detected by the MS. To obtain a comprehensive analysis of the ketones, the Orbitrap MS was used to characterize the ketone fractions (K1 and K2). Comparing with the FT-ICR MS, the Orbitrap MS almost does not have mass discrimination at low mass end and is more suitable for the analysis of K1 and K2 that containing a large number of light compounds, so the mass distribution from the Orbitrap MS should be more close to a quantitative result. The ionization of K1 which consists mainly of long alkyl ketones is seriously suppressed by other polar ketones with more oxygen atoms in ESI in the positive mode (not shown). Figure 6 shows the mass spectrum and relative abundance distribution of assigned class species of K2 by positive-ion ESI Orbitrap MS. The O1 class ketones were the dominant species and had high relative abundance with DBE
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of 6-10. The O2 class also showed high abundances. Other classes such as O3, O4, N1O1, N1O2, etc. exhibited low abundances. These ketone classes were effectively ionized by positive ESI with HCOONH4 as ionization promoter44 due to the high aromaticity. This result was consistent with the GC-MS analysis and the FT-ICR MS analysis of the GirT derivatives of the coal tar to a certain degree.
DBE
C12H15O1 C11H13O1 C13H17O1 C15H19O1 C16H21O1
1 7 13 19
2 8 14 20
3 9 15 21
4 10 16 22
5 11 17 23
6 12 18
DBE=6
C18H25O1
C10H11O1
N1O1 N1O2 N1O3 N1O4 N2O1 N2O2
100
150
200
250
300 m/z
350
O1
400
O1S1
O2
450
O3
O4
500
Figure 6 Mass spectrum and relative abundance distribution of assigned class species of K2 by positive-ion ESI Orbitrap MS.
Figure 7 shows the iso-abundance map of DBE versus carbon number distribution for O1 class species (corresponding to N3O1 in Figure 3) of the coal tar (Figure 7 (a) ) by positive-ion ESI FT-ICR MS and K1 (Figure 7 (b) ) and K2 (Figure 7 (c) ) by positive-ion ESI Orbitrap MS. K1 has the DBE values 1-18 with longer alkyl side chains compared to K2. The compounds with DBE value 1-5 are mainly enriched in K1. A DBE of 1 represents mainly aliphatic methyl ketones and small quantities 3-, 4-alkanones or other alkanones. The carbon number ranges 5-30 of aliphatic ketones in Figure 7 (a) which show high abundance in 10-18 ranges was different from Figure 7 (b), mainly due to the operation loss of GirT derivatives of ketones with carbon number less than 18 during the extrography procedure and/or the ionization suppression caused by aromatic ketones in Figure 7 (b). Ketones with 2 DBEs should be cyclopentanones (or cyclohexanones). A DBE of 5 corresponds to
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C7-C29 alkyl phenyl ketones ( C1-C23 alkyl phenones). While in K2 (see Figure 7 (c) ) the DBE is mainly distributed in 6-11 with a shorter alkyl side chain. The highest relative abundance was at DBE of 6, which mainly represents indanone series and small quantities tetralone series. A DBE of 7 may correspond to the tricyclic diterpenoid biomarker series containing carbonyl functional groups. A DBE of 8 represents alkyl naphthyl ketones, a biomarker series of steroid and tricyclic diterpenes containing carbonyl functional groups. Species with DBE of 9 correspond to the benzophenone, dihydro-phenanthrone series. A DBE of 10 represents fluorenone and anthrone series, and DBE 11 corresponds to acetylanthracene, acetylphenanthrene, acetylfluorene series. DBE 13 represents the benzofluorenone series. The aromatic ketones are more ionizable with HCOONH4 as ionization promoter and show high abundance in Figure 7 (b) and (c), while the aliphatic ketones at DBE value 1, 2 and 3 respond weakly by positive-ion ESI resulting in relatively low abundance in Figure 7 (b). The difference between Figure 7 (a), (b) and (c) is probably due to the different ionization efficiency of GirT derivatives and ketones. For GirT derivatives, a charged quaternary ammonium moiety was introduced into the poorly ionizable carbonyl compounds, resulting in an enhanced sensitivity in ESI in the positive mode. The structure of the original ketones has little effect on the ionization efficiency for GirT derivatives, but it plays a decisive role for K1 and K2. For example, aliphatic ketones are strongly suppressed by aromatic ketones with HCOONH4 as ionization promoter causing them too difficult to be detected in the positive ion ESI compared to its GirT derivatives. Also, there is some losses of aliphatic ketone GirT derivatives during the extrography process, indicating that aliphatic ketones should be analyzed by GirT derivatization followed by +ESI MS. Under the circumstance of almost similar derivatization yields, the relative abundance of GirT derivatives is more likely to reflect the content of the original ketones in the coal tar compared to K1 and K2. Therefore, the most abundant O1 class species of the coal tar is mainly distributed in the DBE range of 1-6, in which the aliphatic ketones at DBE 1 show highest abundance with the carbon number mainly distributed in 10-18, followed by indanone ACS Paragon Plus Environment
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series of DBE 6.
N3O1
Orbitrap MS O1
DBE
22 20 18 16 14 12 10 8 6 4 2 0
O R1
R
Orbitrap MS O1
22
22
20
20
18
18
16
16
14
14
12
12 10
DBE
FT-ICR MS O1
DBE
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
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10 8
8
6
6
4
4
2
5
10
15
20
25
30
35
40
R
2
0
0
O
0 0
5
10
15
20
25
30
35
40
0
5
10
15
20
25
Carbon Number
Carbon Number
Carbon Number
a
b
c
30
35
40
Figure 7 Relative ion abundance plots (DBE versus carbon number) of O1 class species from the positive-ion ESI FT-ICR mass spectra of GirT derivatives of the coal tar (a), the positive-ion ESI Orbitrap mass spectra of K1 (b) and K2 (c).
4. CONCLUSIONS A separation and characterization approach was successfully applied for the investigation of ketones in the low temperature coal tar. Ketones were separated from the coal tar by a chemical derivatization process with Girard T reagent followed by a hydrolysis process of the derivatives. The ketones were assigned to 12 class species by high resolution MS analysis: O1-5, O1S1, N1O1-4 and N2O1-2, among which O1 class species was the most abundant. The long chain alkyl ketones such as aliphatic 2-, 3-, 4- ketones, alkylcyclopentanones, alkyl phenyl ketones and aromatic ketones such as indanone, cyclopentenone, tetralone, acetonaphthone, dihydro-phenanthrenone, benzophenone,
fluorenone,
fluorenyl
formaldehyde,
acetylanthracene,
formaldehyde,
acetylphenanthrene,
anthrone,
anthracene
acetylfluorene,
and
benzofluorenone were identified by GC-MS. In addition, C18-isoprenoid methyl ketone, and tricyclic terpenoids and steroids with one or two oxygen atoms were identified in the coal tar. The results revealed details of molecular composition of ketones in the coal tar and the characterization approach is potential to the study of ketones in other complex mixture such as petroleum and environmental samples.
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ACKNOWLEDGEMENTS The research is supported by the National Natural Science Foundation of China (NSFC 41773038) and the National High Technology Research and Development Program 863 (2011AA05A202).
AUTHOR INFORMATION *E-mail:
[email protected] Tel: +86 10 89739157
ORCID: 0000-0002-1363-1237 Notes: The authors declare no competing financial interest.
REFERENCES 1.
Omais, B.; Courtiade, M.; Charon, N.; Thiébaut, D.; Quignard, A. Characterization of Oxygenated Species in Coal Liquefaction Products: An Overview. Energy & Fuels, 2010. 24(11): 5807-5816. 2. Ni, H.; Hsu, C. S.; Ma, C.; Shi, Q.; Xu, C. Separation and Characterization of Olefin/Paraffin in Coal Tar and Petroleum Coker Oil. Energy & Fuels, 2013. 27(9): 5069-5075. 3. Estep, P. A.; Karr Jr, C. Quantitative Infrared Microanalysis of High-Boiling Aliphatic Neutral Oil Fractions. Analytical Chemistry, 1964. 36(11): 2215-2218. 4. Bartle, K. D.; Jones, D. W.; Martin, T. G.; Wise, W. S. Characterisation of the Neutral Oil from a Low‐Temperature Coal Tar. Journal of Chemical Technology and Biotechnology, 1970. 20(6): 197-202. 5. Chang, T.-C. L.; Karr, C. Gas-Liquid Chromatographic Analysis of Aromatic Hydrocarbons Boiling up to 218° in a Low-Temperature Coal Tar. Analytica Chimica Acta, 1959. 21(61): 474-490. 6. Chang, T.-C. L.; Karr, C. Gas-Liquid Chromatographic Analysis of Aromatic Hydrocarbons Boiling between 202° and 280° in a Low-Temperature Coal Tar. Analytica Chimica Acta, 1961. 24(61): 343-356. 7. Karr Jr, C.; Brown, P. M.; Estep, P. A.; Humphrey, G. L. Identification and Determination of Low-Boiling Phenols in Low Temperature Coal Tar. Analytical Chemistry, 1957. 30(8): 1413-1416. 8. Karr Jr, C.; Estep, P. A.; Hirst Jr, L. L. Countercurrent Distribution of High-Boiling Phenols from a Low-Temperature Coal Tar. Analytical Chemistry, 1960. 32(4): 463-475. 9. McClennen, W. H.; Meuzelaar, H. L. C.; Metcalf, G. S.; Hill, G. R. Characterization of Phenols and Indanols in Coal-Derived Liquids: Use of Curie-Point Vaporization Gas Chromatography/Mass Spectrometry. Fuel, 1983. 62(12): 1422-1429. 10. Burchill, P.; Herod, A. A.; Mahon, J. P.; Pritchard, E. Comparison of Methods for the Isolation of Basic Nitrogen Compounds from Coal Tars. Journal of Chromatography A, 1983.
ACS Paragon Plus Environment
Page 18 of 21
Page 19 of 21 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Energy & Fuels
11. 12. 13.
14.
15.
16. 17.
18. 19. 20. 21. 22. 23. 24. 25.
26. 27.
28.
265(2): 223-238. Burchill, P.; Herod, A. A.; Ernest, P. Investigation of Nitrogen Compounds in Coal Tar Products. 2. Basic Fractions. Fuel, 1983. 62(1): 20-29. Burchill, P.; Herod, A. A.; Pritchard, E. Investigation of Nitrogen Compounds in Coal Tar Products. 1. Unfractionated Materials. Fuel, 1983. 62(1): 11-19. Long, H.; Shi, Q.; Pan, N.; Zhang, Y.; Cui, D.; Chung, K. H.; Zhao, S.; Xu, C. Characterization of Middle-Temperature Gasification Coal Tar. Part 2: Neutral Fraction by Extrography Followed by Gas Chromatography–Mass Spectrometry and Electrospray Ionization Coupled with Fourier Transform Ion Cyclotron Resonance Mass Spectrometry. Energy & Fuels, 2012. 26(6): 3424-3431. Taylor, W. F.; Frankenfeld, J. W. Deposit Formation from Deoxygenated Hydrocarbons. 3. Effects of Trace Nitrogen and Oxygen Compounds. Industrial & Engineering Chemistry Product Research and Development, 1978. 17(1): 86-90. Taylor, W. F.; Wallace, T. J. Kinetics of Deposit Formation from Hydrocarbons. Effect of Trace Sulfur Compounds. Industrial & Engineering Chemistry Product Research and Development, 1968. 7(3): 198-202. Batts, B. D.; Fathoni, A. Z. A Literature Review on Fuel Stability Studies with Particular Emphasis on Diesel Oil. Energy & Fuels, 1991. 5(1): 2-21. Epping, R.; Kerkering, S.; Andersson, J. T. Influence of Different Compound Classes on the Formation of Sediments in Fossil Fuels During Aging. Energy & Fuels, 2014. 28(9): 5649-5656. Alhassan, A.; Andersson, J. T. Effect of Storage and Hydrodesulfurization on the Ketones in Fossil Fuels. Energy & Fuels, 2015. 29(2): 724-733. Petrov, L. V.; Solyanikov, V. M. Acid-Catalyzed Formation of Free Radicals in the Reaction of Hydroperoxides with Ketones. Russian Chemical Bulletin, 1996. 45(2): 340-345. Alhassan, A.; Andersson, J. T. Ketones in Fossil Materials—a Mass Spectrometric Analysis of a Crude Oil and a Coal Tar. Energy & Fuels, 2013. 27(10): 5770-5778. Harvey, T. G.; Matheson, T. W.; Pratt, K. C. Chemical Class Separation of Organics in Shale Oil by Thin-Layer Chromatography. Analytical Chemistry, 1984. 56(8): 1277-1281. Leif, R. N.; Simoneit, B. R. T. Ketones in Hydrothermal Petroleums and Sediment Extracts from Guaymas Basin, Gulf of California. Organic Geochemistry, 1995. 23(10): 889-904. Iida, T.; Yoshii, E.; Kitatsuji, E. Identification of Normal Paraffins, Olefins, Ketones, and Nitriles from Colorado Shale Oil. Analytical Chemistry, 1966. 38(9): 1224-1227. Strelnikova, E.; Stakhina, L.; Serebrennikova, O. Separation of Ketones and Acids from Crude Oils. Petroleum & Coal, 2005. 47(3): 16-20. Strel’nikova, E. B.; Stakhina, L. D.; Petrenko, T. V. Preconcentration of Petroleum Organic Acids and Ketones by Two-Stage Chromatography Using a Modified Adsorbent. Journal of Analytical Chemistry, 2009. 64(1): 8-13. Strelnikova, E. B.; Serebrennikova, O. V. Ketones of Western Siberian Jurassic Oils. Petroleum Chemistry, 2011. 51(4): 264-269. Willsch, H.; Clegg, H.; Horsfield, B.; Radke, M.; Wilkes, H. Liquid Chromatographic Separation of Sediment, Rock, and Coal Extracts and Crude Oil into Compound Classes. Analytical Chemistry, 1997. 69(20): 4203-4209. Neto, C. C.; Maçaira, A. M. P.; Pinto, R. C. P.; Nakayama, H. T.; Cardoso, J. N. New
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Energy & Fuels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
29. 30.
31.
32. 33. 34. 35.
36.
37. 38. 39. 40. 41.
42.
43.
44. 45.
Analytical Approaches to Organic Geochemistry: Solid Phase Functional Group Extraction for Bitumens and Functional Group Markers for Kerogens. Physics and Chemistry of the Earth, 1980. 12(79): 249-263. Bennett, B.; Larter, S. R. The Isolation, Occurrence and Origin of Fluorenones in Crude Oils and Rock Extracts. Organic Geochemistry, 2000. 31(1): 117-125. Ruddy, B. M.; Huettel, M.; Kostka, J. E.; Lobodin, V. V.; Bythell, B. J.; McKenna, A. M.; Aeppli, C.; Reddy, C. M.; Nelson, R. K.; Marshall, A. G. Targeted Petroleomics: Analytical Investigation of Macondo Well Oil Oxidation Products from Pensacola Beach. Energy & Fuels, 2014. 28(6): 4043-4050. Harvey, T. G.; Matheson, T. W.; Pratt, K. C.; Stanborough, M. S. Determination of Carbonyl Compounds in an Australian (Rundle) Shale Oil. Journal of Chromatography A, 1985. 319(2): 230-234. Regtop, R. A.; Crisp, P. T.; Ellis, J. Chemical Characterization of Shale Oil from Rundle, Queensland. Fuel, 1982. 61(2): 185-192. George, S. C.; Jardine, D. R. Ketones in a Proterozoic Dolerite Sill. Organic Geochemistry, 1994. 21(8): 829-839. Wilkes, H.; Disko, U.; Horsfield, B. Aromatic Aldehydes and Ketones in the Posidonia Shale, Hils Syncline, Germany. Organic Geochemistry, 1998. 29(1): 107-117. Azevedo, D. A.; Zinu, C. J. A.; Neto, F. R. A.; Simoneit, B. R. T. Possible Origin of Acyclic (Linear and Isoprenoid) and Tricyclic Terpane Methyl Ketones in a Tasmanian Tasmanite Bitumen. Organic Geochemistry, 2001. 32(3): 443-448. Oldenburg, T. B. P.; Wilkes, H.; Horsfield, B.; Van Duin, A. C. T.; Stoddart, D.; Wilhelms, A. Xanthones—Novel Aromatic Oxygen-Containing Compounds in Crude Oils. Organic Geochemistry, 2002. 33(5): 595-609. Rodgers, R. P.; Schaub, T. M.; Marshall, A. G., Petroleomics: MS Returns to Its Roots. In American Chemical Society: 2005. Marshall, A. G.; Rodgers, R. P. Petroleomics: Chemistry of the Underworld. Proceedings of the National Academy of Sciences, 2008. 105(47): 18090-18095. Marshall, A. G.; Rodgers, R. P. Petroleomics: The Next Grand Challenge for Chemical Analysis. Accounts of Chemical Research, 2004. 37(1): 53-59. Zhurov, K. O.; Kozhinov, A. N.; Tsybin, Y. O. Evaluation of High-Field Orbitrap Fourier Transform Mass Spectrometer for Petroleomics. Energy & Fuels, 2013. 27(6): 2974-2983. Smith, E. A.; Park, S.; Klein, A. T.; Lee, Y. J. Bio-Oil Analysis Using Negative Electrospray Ionization: Comparative Study of High-Resolution Mass Spectrometers and Phenolic Versus Sugaric Components. Energy & Fuels, 2012. 26(6): 3796-3802. Pomerantz, A. E.; Mullins, O. C.; Paul, G.; Ruzicka, J.; Sanders, M. Orbitrap Mass Spectrometry: A Proposal for Routine Analysis of Nonvolatile Components of Petroleum. Energy & Fuels, 2011. 25(7): 3077-3082. Smith, E. A.; Lee, Y. J. Petroleomic Analysis of Bio-Oils from the Fast Pyrolysis of Biomass: Laser Desorption Ionization− Linear Ion Trap− Orbitrap Mass Spectrometry Approach. Energy & Fuels, 2010. 24(9): 5190-5198. Lu, J.; Zhang, Y.; Shi, Q. Ionizing Aromatic Compounds in Petroleum by Electrospray with HCOONH4 as Ionization Promoter. Analytical Chemistry, 2016. 88(7): 3471-3475. Shi, Q.; Pan, N.; Long, H.; Cui, D.; Guo, X.; Long, Y.; Chung, K. H.; Zhao, S.; Xu, C.; Hsu,
ACS Paragon Plus Environment
Page 20 of 21
Page 21 of 21 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Energy & Fuels
46.
47.
48. 49. 50. 51. 52. 53.
54.
55. 56. 57.
58.
59.
C. S. Characterization of Middle-Temperature Gasification Coal Tar. Part 3: Molecular Composition of Acidic Compounds. Energy & Fuels, 2012. 27(1): 108-117. Pan, N.; Cui, D.; Li, R.; Shi, Q.; Chung, K. H.; Long, H.; Li, Y.; Zhang, Y.; Zhao, S.; Xu, C. Characterization of Middle-Temperature Gasification Coal Tar. Part 1: Bulk Properties and Molecular Compositions of Distillates and Basic Fractions. Energy & Fuels, 2012. 26(9): 5719-5728. Liu, P.; Xu, C.; Shi, Q.; Pan, N.; Zhang, Y.; Zhao, S.; Chung, K. H. Characterization of Sulfide Compounds in Petroleum: Selective Oxidation Followed by Positive-Ion Electrospray Fourier Transform Ion Cyclotron Resonance Mass Spectrometry. Analytical Chemistry, 2010. 82(15): 6601-6606. Sharkey, A. G.; Shultz, J. L.; Friedel, R. A. Mass Spectra of Ketones. Analytical Chemistry, 1956. 28(6): 934-940. Šaban, M.; Porter, S.; Costello, C.; Djuričić, M.; Vitorović, D. Polar Consituents Isolated from Aleksinac Oil Shale. Physics and Chemistry of the Earth, 1980. 12: 559-566. Tuo, J.; Li, Q. Occurrence and Distribution of Long-Chain Acyclic Ketones in Immature Coals. Applied Geochemistry, 2005. 20(3): 553-568. Ikan, R.; Baedecker, M. J.; Kaplan, I. R. C18-Isoprenoid Ketone in Recent Marine Sediment. Nature, 1973. 244(5412): 154-155. Anders, D. E.; Doolittle, F. G.; Robinson, W. E. Polar Constituents Isolated from Green River Oil Shale. Geochimica et Cosmochimica Acta, 1975. 39(10): 1423-1430. Yang, H. M.; Zhao, W.; Norinaga, K.; Fang, J. J.; Wang, Y. G.; Zong, Z. M.; Wei, X. Y. Separation of Phenols and Ketones from Bio-Oil Produced from Ethanolysis of Wheat Stalk. Separation and Purification Technology, 2015. 152: 238-245. Latham, D. R.; Ferrin, C. R.; Ball, J. S. Identification of Fluorenones in Wilmington Petroleum by Gas-Liquid Chromatography and Spectrometry. Analytical Chemistry, 1962. 34(3): 311-313. Mojelsky, T. W.; Strausz, O. P. Detection of Methyl Fluorenones in Athabasca Oil Sand Bitumens. Organic Geochemistry, 1986. 9(1): 31-37. Mojelsky, T. W.; Strausz, O. P. Detection of Alkylated Fluorenes in Athabasca Oil Sand Bitumens. Organic Geochemistry, 1986. 9(1): 39-45. Otto, A.; Simoneit, B. R. T.; Rember, W. C. Resin Compounds from the Seed Cones of Three Fossil Conifer Species from the Miocene Clarkia Flora, Emerald Creek, Idaho, USA, and from Related Extant Species. Review of Palaeobotany and Palynology, 2003. 126(3): 225-241. Otto, A.; Simoneit, B. R. T.; Wilde, V.; Kunzmann, L.; Püttmann, W. Terpenoid Composition of Three Fossil Resins from Cretaceous and Tertiary Conifers. Review of Palaeobotany and Palynology, 2002. 120(3): 203-215. Otto, A.; Simoneit, B. R. T. Chemosystematics and Diagenesis of Terpenoids in Fossil Conifer Species and Sediment from the Eocene Zeitz Formation, Saxony, Germany. Geochimica et Cosmochimica Acta, 2001. 65(20): 3505-3527.
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