Benzenetricarboxylic Acids Research Articles

Molecular-scale investigation on the composition, sources and secondary generation of organic aerosols in polluted central China

Molecular analyses help to better understand the overall picture of characteristics, meteorological effects, sources, and secondary transformations of organic aerosols (OA). A two-year observation campaign was conducted in polluted central China during 2019–2021, and 130 compounds of molecular OA (quantified organic compounds, QOCs) were quantified. The average concentration of QOCs was 1971 ng/m3, showing the highest normalized QOCs in PM2.5 (31 ng/μg) compared to others. Among the QOCs, the polar category contributed 84%, with the dominated abundant fatty acids observed. The enhanced acid ratios of malonic/succinic and octadecanoic/oleic in summer indicated higher aerosol age, significantly promoted by temperature. Three benzenetricarboxylic acids, mostly from secondary formation, also exhibited quite high concentrations in summer. The noticeable presence of carcinogenic polycyclic aromatic hydrocarbons (PAHs) (45% of ∑28PAHs) highlighted severe health risks associated with human exposure, particularly in winter (56 ng/m3, approximately 7 times that in summer). According to the random forest model assessments, meteorological conditions in summer were most conducive to eliminating pollutants, while that in winter contributed 19% of QOC concentration. The Positive Matrix Factorization analysis revealed that anthropogenic secondary organic aerosols (ASOA) and biogenic SOA (BSOA) jointly accounted for 32% of QOCs, followed by biomass burning (20%), coal combustion (17%), vehicle emissions (16%), and cooking (15%). ASOA was positively correlated with O3 (r = 0.58) and aerosol acidity facilitated ASOA production at 40% < relative humidity <80%. On polluted days, BSOA increased as NO2 and PM2.5 increased, contributing to worsened aerosol pollution. In spring and summer, gas-phase oxidation contributed more saturated dicarboxylic acids (52 and 55%), while aqueous-phase conversion predominated in autumn and winter (59 and 66%). This study provides new information on particulate molecular organic compounds as well as the secondary transformation, which is of great significance for formulating the prevention and control measures of aerosol pollution.

Abundance and sources of particulate polycyclic aromatic hydrocarbons and aromatic acids at an urban site in central China

We conducted a simultaneous field study of PM2.5-bound particulate polycyclic aromatic hydrocarbons (PAHs) and aromatic acids (AAs) in a polluted city Zhengzhou to explore the concentration, sources and potential conversion pathways between PAHs and AAs in different seasons. The average concentrations of PM2.5, 28PAHs and 8AAs during the sampling period were 77 µg/m3, 75 ng/m3, and 283 ng/m3, respectively. The concentration of both 28PAHs and 8AAs were highest in winter and lowest in summer with ratios of 6.3 and 2.3, respectively. PAHs with 5–7 rings were the main components of PAHs (52%), followed by 4 rings PAHs (30%) and 2–3 rings PAHs (18%). According to the source appointment results obtained by positive matrix factorization, the main sources of PAHs were combustion and vehicle emissions, which account for 37% and 34%, respectively. 8AAs were divided into three groups, including four benzene dicarboxylic acids (B2CAs), three benzene tricarboxylic acids (B3CAs) and one benzene tetracarboxylic acid (B4CA). And interspecies correlation analysis with PM2.5 source markers were used to investigate potential sources. Phthalic acid (o-Ph) was the most abundant specie of 8AAs (157 ng/m3, 55% of 8AAs), which was well correlated with sulfate. Meanwhile, B3CAs and B4CA were highly correlated with sulfate and weakly correlated with levoglucosan, suggesting that secondary formation was their main source. As logical oxidation products of PAHs, o-Ph and B3CAs showed good correlations with a number of PAHs, indicating possible photochemical oxidation pathway by PAHs. In addition, O3, NO2, temperature and relative humidity have positive effects on the secondary formation of B3CAs.

Fully organic polyaniline nanotubes as electrode material for durable supercapacitor

Herein, we have reported fully organic acid doped polyaniline nanotube as a metal free electrode material for supercapacitor device fabrication. The energy storage behavior of this polymer greatly depends with morphology of nanostructure that has been optimized by using different number of carboxylic groups functionalized organic acid like benzene dicarboxylic acids (OA2), benzene tricarboxylic acids (OA3) and benzene tetracarboxylic acids (OA4). Prepared nanostructures were characterized by UV–Vis, XRD, FTIR, FESEM and HRTEM. Importantly, the charge storage properties of nanostructure were studied by Cyclic voltammetry (CV), galvanic charge discharge (GCD) and electrochemical impedance spectroscopy (EIS). It has been noticed that benzene tetracarboxylic acids (OA4) doped polyaniline (OA4PAN) is the optimum nanostructure having specific capacitance ~ 400 F/g at 0.5 A/g in the three-electrode system. A symmetrical solid-state device with excellent mechanical flexibility has been fabricated with optimized nanostructure revealed the specific capacitance of 107 F/g at a 0.2 A/g in wide potential window with high cyclic stability up to 5000 cycle at 2 A/g (~91% retention of specific capacitance). This nanostructure could be eligible to use for various energy storage system in near future.

A Series of Metal–Organic Frameworks: Syntheses, Structures and Luminescent Detection, Gas Adsorption, Magnetic Properties

Six metal–organic frameworks of [Cd2(L)2(mmpa)2]·6H2O (1), [Mn2(L)2(mmpa)2]·L·2H2O (2), [Zn(L)(NO2 mbda)]·H2O (3), [Cu(L)(NO2 mbda)] (4), [Co3(L)2(BTC)2(H2O)4]·H2O (5), and [Co3(L)2(OBTC)2(H2O)2] (6) were prepared based on different metal salts and the mixed ligands including the N-heterocyclic 1-(4-(1H-imidazol-5-yl)phenyl)-1H-1,2,4-triazole (L) ligand and auxiliary carboxylic acids of 5-methylisophthalic acid (H2 mmpa), 5-nitroisophthalic acid (H2NO2 mbda), trimesuc acid (H3BTC), and 1,2,3-benzenetricarboxylic acid (H3OBTC). MOFs 1 and 2 are isomorphous and isostructural, and both are binodal 4-connected CdS network based on Cd2(COO)2 binuclear secondary building unit (SBU). Compound 3 is a 2D → 3D “polycatenated network” because of its mutual interpenetration between two-dimensional (2D) corrugated (4, 4) layers, while 4 is a sql network on the basis of binuclear [Cu2(COO)2] SBUs. Compound 5 is a trinodal (3, 4)-connected rare nor-3,4-C2/m 3-fold interpenetrated net, while 6 is a 4-connected 3D frl/Ferey ladder net based on L and two isomers of benzenetricarboxylic acids. Photoluminescent properties were determined for the corresponding d10 MOFs. Microporous crystalline material 1 can selectively sense nitroaromatic compounds by fluorescence quenching and show a rare luminescent sensing property for Ag+ ions in H2O solution. Also, the activated microporous material 1 can selectively adsorb CO2 over N2 and undergo H2O vapor adsorption. Furthermore, magnetostructural analyses have also shown that MOFs 2, 4, 5, and 6 consisting of the paramagnetic ions Mn(II), Cu(II)/Co(II), and carboxylate or N-heterocyclic organic molecules exhibit meaningful magnetic-exchange coupling properties.

Nanopatterns of molecular spoked wheels as giant homologues of benzene tricarboxylic acids.

Molecular spoked wheels with D3h and Cs symmetry are synthesized by Vollhardt trimerization of C2v-symmetric dumbbell structures with central acetylene units and subsequent intramolecular ring closure. Scanning tunneling microscopy of the D3h-symmetric species at the solid/liquid interface on graphite reveals triporous chiral honeycomb nanopatterns in which the alkoxy side chains dominate the packing over the carboxylic acid groups, which remain unpaired. In contrast, Cs-symmetric isomers partially allow for pairing of the carboxylic acids, which therefore act as a probe for the reduced alkoxy chain nanopattern stabilization. This observation also reflects the adsorbate substrate symmetry mismatch, which leads to an increase of nanopattern complexity and unexpected templating of alkoxy side chains along the graphite armchair directions. State-of-the-art GFN-FF calculations confirm the overall structure of this packing and attribute the unusual side-chain orientation to a steric constraint in a confined environment. These calculations go far beyond conventional simple space-filling models and are therefore particularly suitable for this special case of molecular packing.

Coplanar versus Noncoplanar Carboxyl Groups: The Influence of Sterically Enforced Noncoplanarity on the 2D Mixing Behavior of Benzene Tricarboxylic Acids

Hydrogen bonding is an indispensable tenet in the fabrication of surface-confined physisorbed supramolecular networks. On-surface supramolecular chemistry is dominated by aromatic carboxylic acids,...

Production of Benzenecarboxylic Acids from Geting Bituminous Coal through Oxidation with NaOCl Enhanced by Pretreatment with H2O2

AbstractBenzenecarboxylic acids (BCAs) are valuable chemicals with a wide range of applications, which can be produced from coals via mild oxidation. Herein, an effective approach for producing BCAs from Geting bituminous coal (GBC) is reported through oxidation with NaOCl aqueous solution enhanced by pretreatment with H2O2 aqueous solution. Both GBC and pretreated GBC (PTGBC) undergo oxidation with NaOCl at 30 °C for 24 h. The results show that pretreatment with H2O2 enhance the yields of non‐chlorine BCAs and meanwhile suppress producing chloro‐substituted BCAs from GBC. BCAs produced from oxidation of PTGBC have a high total yield of 21.0 wt %, among which benzenedicarboxylic acids, benzenetricarboxylic acids, and benzenetetracarboxylic acids are predominant. The distributions of BCAs reveal that GBC has more cata‐condensed aromatics and peri‐condensed aromatics than polyaryls moieties. The possible mechanisms for enhancing BCAs production by pretreatment with H2O2 are discussed.

Abundance and Sources of Phthalic Acids, Benzene-Tricarboxylic Acids, and Phenolic Acids in PM2.5 at Urban and Suburban Sites in Southern China

The organic composition of airborne fine particulate matter (PM2.5, aerodynamic diameter less than 2.5 μm) at a molecular level has yet to be achieved, hindering a full understanding of the climatic impacts and health effects of PM2.5. Compounds containing aromatic rings are closely associated with optically active brown carbon and toxicologically important quinones. In this work, a group of ten aromatic organic acids including three phthalic acids, four phenolic acids, and three benzene-tricarboxylic acids (BTCAs) in PM2.5 were studied for their abundance and potential sources through quantifying their ambient concentrations at four sites in the Pearl River Delta (PRD) region in Southern China, where biomass burning and anthropogenic emissions are both significant PM sources. Average concentrations of individual aromatic acids in a total of 240 PM2.5 samples collected throughout 2012 were in the order of 0.1–20 ng/m3 with p-and o-phthalic acid being the most abundant. Interspecies correlation analysis wi...

The generation of benzene carboxylic acids from lignite and the change in structural characteristics of the lignite during oxidation

Production of carboxylic acids (including 12 types of benzene carboxylic acids (BCAs) and small-molecule fatty acids) from lignite via oxidation has been widely studied, but few studies addressed the relationship between distribution of BCAs and structure of lignite. This work studies alkali-oxygen oxidation of Xiaolongtan lignite and distributions of BCAs with 13C NMR as well as the relationship between the distributions of BCAs and the lignite structures. The results indicate that the dominant aromatic structures in the lignite are naphthalene and benzene with a mole ratio of around 3, and an alkyl-substituted degree of aromatic rings of 0.359. These structure characters determine that the yields of benzene tricarboxylic acids, benzene tetracarboxylic acids, benzene pentacarboxylic acid and mellitic acid are more than those of other BCAs. In the oxidation process, the organic matter of lignite is first converted to humic acids (HAs), then to water soluble acids, and last to carboxylic acids. The last conversion step is the rate-controlling step. Analyses of the residues and HAs indicate that C–O bond of lignite is easily cleaved. The aromatic structures (except condensed aromatic rings) are easily depolymerized from lignite, but the condensed aromatic rings and long alkyl chains are difficult to be oxidized. With an increase in oxidation time, in the residues, the contents of aromatic structures decrease, but the contents of condensed aromatic rings and long alkyl chains both increase. While in HAs, the contents of condensed aromatic rings increase, but the average methylene chain length (Cn) decreases.

Separation of the isomers of benzene poly(carboxylic acid)s by quaternary ammonium salt via formation of deep eutectic solvents.

Because of similar properties and very low volatility, isomers of benzene poly(carboxylic acid)s (BPCAs) are very difficult to separate. In this work, we found that isomers of BPCAs could be separated efficiently by quaternary ammonium salts (QASs) via formation of deep eutectic solvents (DESs). Three kinds of QASs were used to separate the isomers of BPCAs, including the isomers of benzene tricarboxylic acids (trimellitic acid, trimesic acid, and hemimellitic acid) and the isomers of benzene dicarboxylic acids (phthalic acid and isophthalic acid). Among the QASs, tetraethylammonium chloride was found to have the best performance, which could completely separate BPCA isomers in methyl ethyl ketone solutions. It was found that the hydrogen bond forming between QAS and BPCA results in the selective separation of BPCA isomers. QAS in DES was regenerated effectively by the antisolvent method, and the regenerated QAS was reused four times with the same high efficiency.

Pyrogenic molecular markers: Linking PAH with BPCA analysis

Molecular characterization of pyrogenic organic matter (PyOM) is of great interest to understand the formation and behavior of these increasingly abundant materials in the environment. Two molecular marker methods have often been used to characterize and trace PyOM: polycyclic aromatic hydrocarbon (PAH) and benzenepolycarboxylic acid (BPCA) analysis. Since both methods target pyrogenic polycyclic compounds, we investigated the linkages between the two approaches using chars that were produced under controlled conditions. Rye and maize straws and their analogues charred at 300, 400 and 500°C, respectively, were thus analyzed with both methods. Moreover, we also measured BPCAs directly on the lipid extracts, on which PAHs were analyzed, and on the respective extraction residues, too. Both methods revealed important features of the chars, in particular the increasing degree of aromatic condensation with increasing highest heating temperature (HTT). The overlap between the two methods was identified in the lipid fraction, where the proportion of benzenetricarboxylic acids (B3CAs) correlated with PAH abundance. The results confirmed the validity and complementarity of the two molecular marker methods, which will likely continue to play a crucial role in PyOM research due to the recent developments of compound-specific PAH and BPCA stable carbon (δ13C) and radiocarbon (14C) isotope methods.

Influence of functional groups on the adsorption behaviour of substituted benzoic acids at the α-alumina/water interface

Adsorption kinetics of hemimellitic and trimellitic acids at a fixed initial concentration of 0.30 mM onto α-alumina surfaces were carried out in batch method in the presence of 0.05 mM NaCl(aq) at pH 5 and 288.15, 298.15, 303.15, and 313.15 K. The experimental data were significantly better fitted to pseudo-second-order kinetic equation of non-linear form in the entire time duration. The state of equilibration time of benzenetricarboxylic acids at 298.15 K follows the sequence: hemimellitic acid < trimellitic acid < trimesic acid. Adsorption isotherms of hemimellitic and trimellitic acids were carried out at 298.15 K, pH 5–10, and 0.05 mM NaCl(aq) by varying acid concentration. The adsorption data were fitted to Langmuir adsorption model. Adsorption density of benzenetricarboxylic acids follows the sequence: trimesic acid < trimellitic acid < hemimellitic acid. Comparison of the adsorption densities of benzenetricarboxylic acids with dihydroxybenzoic and monohydroxybenzoic acids indicates that (i) in benzenetricarboxylic acids the position and equally the number of –COOH groups, (ii) the two phenolic –OH groups at any two position in the benzene ring of dihydroxybenzoic acids, and (iii) the phenolic –OH groups at ortho position in the benzene ring of monohydroxybenzoic acids are the governing parameters for yielding higher adsorption density onto α-alumina surface. Exception is the 2,4-dihydroxybenzoic acid amongst dihydroxybenzoic acids series, which yields highest adsorption density due to ortho and para position of the phenolic –OH groups. The thermodynamic data indicate that the adsorption process is spontaneous for both the systems. The magnitude of shifting of ν s(–COO −) and ν as(–COO −) after adsorption of trimellitic and hemimellitic acids onto α-alumina surface indicate that both acids form outer-sphere surface complexes.

Aerobic oxidation of trimethylbenzenes catalyzed by N,N′,N″-trihydroxyisocyanuric acid (THICA) as a key catalyst

The oxidation of trimethylbenzenes was examined with air or O2 using N,N′,N″-trihydroxyisocyanuric acid (THICA) as a key catalyst. Thus, 1,2,3-, 1,2,4-, and 1,3,5-trimethylbenzenes under air (20 atm) in the presence of THICA (5 mol %), Co(OAc)2 (0.5 mol %), Mn(OAc)2, and ZrO(OAc)2 at 150 °C were oxidized to the corresponding benzenetricarboxylic acids in good yields (81–97%). In the aerobic oxidation of 1,2,4-trimethylbenzene by the THICA/Co(II)/Mn(II) system, remarkable acceleration was observed by adding a very small amount of ZrO(OAc)2 to the reaction system to form 1,2,4-benzenetricarboxylic acid in excellent yield (97%). In contrast, no considerable addition effect was observed in the oxidation of 1,3,5-trimethylbenzene. This aerobic oxidation by the present catalytic system provides an economical and environmentally benign direct method to benzenetricarboxylic acids, which are very important polymer materials.

New hydrazinium salts of benzene tricarboxylic and tetracarboxylic acids—preparation and their thermal studies

Some new hydrazinium salts of benzene tricarboxylic and tetracarboxylic acids have been prepared by neutralisation of these acids with hydrazine hydrate in aqueous medium and characterised by conductance measurement, IR spectral and thermal analyses. Hemimellitic acid (H 3hml) forms monohydrazinium salt, trimellitic acid (H 3tml) and trimesic acid (H 3tms), mono and dihydrazinium salts, and pyromellitic acid (H 4pml) all the four salts with hydrazine hydrate. Conductance study indicates their electrolytic nature. IR spectra of all the salts show NN stretching frequencies of the N 2H 5 + in the region of 960–990 cm −1. The hemimellitate salt undergoes endothermic dehydrazination at 154 °C, trimellitates and pyromellitates in the range of 191–271 °C, and trimesates in the range of 267–332 °C. Trimesates decompose to give CO 2 around 337 °C. All the salts then undergo strong exothermic decomposition in the range of 517–595 °C via the formation of respective acid intermediates first, then arenes, yielding carbon residue. A comparison of the thermal behaviour of pure acids with that of their salts reveals the fact that the acids do not withstand high temperature like salts. They show sharp endotherms at their melting points and then they decompose exothermally before 400 °C to give carbon residue.

Ruthenium complex catalyzed polymerization of OH or COOH group containing alkynes to give functionalized poly(acetylene)s

The ruthenium(III) complex [(Cp*)RuCl 2] 2 (Cp*=permethylcyclopentadienyl) catalyzes polymerization of propiolic acid to give a mixture of poly(propiolic acid), [CHC(COOH)] n ( 1), and cyclic trimers, 1,2,4- and 1,3,5- benzenetricarboxylic acids. GPC analysis shows MN and MW values of the polymer of 4.0 × 10 3 and 4.3 × 10 3, respectively. Reaction of propiolic acid in the presence of the Ru(II) complex, (Cp*)RuCI(L) (L=1,5-cyclooctadiene and norbornadiene), gives the cyclic trimers rather than 1. [(Cp*)RuCl 2] 2 catalyzes polymerization of acetylenedicarboxylic acid and of propargyl alcohol to give the corresponding poly(acetylene) derivatives, [C(COOH)C(COOH)] n ( 2) and [CHC(CH 2OH)] n ( 3), respectively. Polymerization of ethyl propiolate, 2-butyn-1,4-diol, phenylacetylene and (trimethylsilyl)acetylene using [(Cp*)RuCl 2] 2 gives the corresponding polymers [CHC(COOEt)] n ( 4), [C(CH 2OH)C(CH 2OH)] n ( 5), [CHCPh] n ( 6) and [CHC(SiMe 3)] n ( 7) in low yields.

Novel regular network polyester films from benezenetricarboxylic acids and glycols

AbstractNovel regular network polyester films were prepared from benzenetricarboxylic acids of trimesic (Y) and trimellitic (Z) acids, and glycols of ethylene (2G), tetramethylene (4G), and hexamethylene (6G) glycols. Prepolymers prepared by melt polycondensation for a short period within 1 h were cast from a DMF solution and successively post‐polymerized at various temperatures and times to form a network. The resultant films were transparent, flexible, and insoluble in any solvents. Distortion temperature measured by a penetration mode of thermomechanical analysis (TMA) increased with increasing post polymerization time and temperature, and leveled out at 222, 168, 125 and 75°C, for the 2GY, 2GZ, 4GY, and 6GY films, respectively. Temperatures close to 400°C at which the probe had completely penetrated corresponded to the thermal decomposition temperature of these films. Two broad but strong peaks in the x‐ray diffraction curves appears for the 2GY, 4GY, and 6GY, suggesting the formation of some ordered supramolecular structure owing to the regular network formed by symmetrical trimesic acid moiety, and the intensity of diffraction peaks became higher with increasing length of the methylene chain of the glycol monomer. Densities of the 2GY and 2GZ films decreased with increasing post‐polymerization time and temperature. Tensile strength and Young's modulus increased and elongation decreased with increasing network formation. These tensile properties was affected by the chemical structure of the network films.

The reaction of ozone with isolated aquatic fulvic acid

Aquatic fulvic acid, isolated from a North Carolina bay lake, was reacted with ozone, an alternative oxidant in drinking water treatment. Ozonated samples were acidified, extracted with ether, dried, concentrated, and methylated prior to GC-MS analysis. Identified reaation products include mono-, di- and tribasic aliphatic acids and benzene tricarboxylic acids. The products with the highest relative concentrations were succinic and malonic acid, although all products were at relatively low concentration levels. Many of the products identified in this study have also been seen among the reaction products of fulvic acid and other oxidants, such as Cl 2, CIO 2 and KMnO 4.

The hypolipidemic activity of benzenetricarboxylic acids in rodents.

A series of benzenetricarboxylic acids was shown to be potent hypolipidemic agents in rodents. Terephthalic acid proved to be one of the more potent agents, lowering serum cholesterol 42% and serum triglyceride 33 % at 20 mg/kg/day for 16 days. The ability to lower serum lipids by this agent appeared to be due to multiple modes of action: (1) terephthalic acid suppressed the activities both in vivo and in vitro of a number of regulatory enzymes involved in cholesterol, fatty acid, and triglyceride syntheses; (2) the drug inhibited cholesterol absorption from the GI tract by 43 %; and (3) the drug accelerated lipid excretion in the feces leading to a reduction of cholesterol in the tissue. Terephthalic acid was effective in lowering lipids in normal and hyperlipidemic animals and possessed a safe therapeutic index.

Spectra of metastableions of positional isomers of methyl benzenepolycarboxylates

1. The method of direct analysis of daughter ions (DADI) has been used in studying 28 positional isomers of the methyl esters of phthalic and benzenetricarboxylic acids. 2. On the basis of the spectra obtained for the metastable ions M+, [M-OCH3 (or CH3OH)]+, and [M-COOCH3 (or HCOOCH3)]+, the isomers in question have been identified successfully. 3. In the DADI spectra of certain isomers, unusual high-intensity peaks with nonintegral values of m/z have been observed.

Carboxylic acids derived from Tasmanian tasmanite by extractions and kerogen oxidations

Tasmanian tasmanite, an organic-rich rock of Permian age, is made up of silt and compressed discs of Tasmanites, a unicellular organism with close biological affinity to the present day marine organisms of the genus Pachysphaera. The investigation of the oarboxylic acids extracted from tasmanite and of carboxylic acids derived from the oxidative degradation of the fossil spore walls has been carried out by gas chromatography, high and low resolution mass spectrometry and gas ohromatography-mass spectrometry. Exhaustive extraction yielded mainly normal acids ( C n H 2 n O 2, n = 5–31) and polycyolic acids, possibly derived from sterol diagenesis. Acids isolated in low concentration after demineralization had essentially the same distribution pattern as the acids derived after saponification, namely normal ( C n H 2 n O 2, n = 8–22), dicarboxylic ( C n H 2 n -2 O 4, n = 9–17) and polycyolic acids. The acids produced by stepwise (six steps) oxidation of the kerogen concentrate were quite varied. The major products obtained from the early oxidations consisted of normal ( C n H 2 n O 2, n = 8–30), dicarboxylic ( C n H 2 n-2 O 4, n = 10–24), polycyclic and aromatic acids, and from the later oxidations mainly smaller and more polar acids: normal ( C n H 2 n O 2, n = 9–12), dicarboxylic ( C n H 2 n-2 O 4, n = 8–12), benzene dicarboxylic ( C n H 2 n-10 O 4, n = 8–10), benzene tricarboxylic ( C n H 2 n-12 O 6, n = 9,10) acids. The major findings of these studies are: 1. (1) tasmanite kerogen is constituted mainly of a random, saturated hydrocarbon polymer, probably derived from saturated and olefinic lipids and sterols 2. (2) the isoprenoid acids are absent in both the extracts and oxidation products.