J. Oró

Closed system Fischer-Tropsch synthesis over meteoritic iron, iron ore and nickel-iron alloy

Abstract Meteoritic iron, iron ore and nickel-iron alloy (either alone or in some cases mixed with alumina, carbonaceous chondrite, potassium carbonate or sodium carbonate) were used to catalyze the reaction of deuterium and carbon monoxide in a closed reaction vessel. The mole ratio of deuterium to carbon monoxide ranged from 1/2:1 to 10:1, the reaction temperature from 195 to 370°C, and the reaction time from 6 to 480 hr. Analysis of the reaction products showed that normal alkanes and alkenes (C 11 -C 25 ), their monomethyl substituted isomers and aromatic hydrocarbons (e.g. naphthalene, acenaphthene, fluorene, phenanthrene and the methyl derivatives of these hydrocarbons) were synthesized. In addition to the aforementioned hydrocarbons, one reaction product was shown to contain perdeutero normal fatty acids (10:0–16:0).

Organic compounds in meteorites—III. Distribution and identification of aliphatic hydrocarbons produced by open flow Fischer-Tropsch processes

Abstract The possible abiotic synthesis of the aliphatic hydrocarbons in extraterrestrial samples was investigated, using as a model, the Fischer-Tropsch reaction between hydrogen and carbon monoxide. Iron of meteoritic origin, as well as commercial nickel and nickel-iron alloys, were used as the catalyst. This type of synthesis produced small amounts of saturated and unsaturated hydrocarbons ranging from C 8 to about C 26 . The saturated hydrocarbons were found to be predominantly n-paraffins plus smaller amounts of methyl branched isomers (7-, 6-, 5-, 4-, 3-, 2-methyl alkanes). The individual concentrations of these synthetic hydrocarbons decrease continuously with molecular weight. Although n-alkanes and their monomethyl branched isomers have been detected by gas chromatographic-mass spectrometric techniques among the products of more than 60 experiments, no traces of isoprenoid hydrocarbons were found.

Organic compounds in meteorites—IV. Gas chromatographic-mass spectrometric studies on the isoprenoids and other isomeric alkanes in carbonaceous chondrites

Abstract Nine homologous series of isomeric alkanes, in addition to the normal alkane series, have been identified by gas Chromatographic and mass spectrometric techniques in the hydrocarbon fractions from the extracts of six carbonaceous chondrites (Essebi, Grosnaja, Mokoia, Murray, Orgueil and Vigarano). Two of these series show isoprenoid structures corresponding to 2,6,10-trimethyl and 2,6,10,14-tetramethyl alkanes ranging from C14 to C18 and C19 to C21, respectively. The rest is made up of five series of monomethyl alkanes (2-, 3-, 4-, 5-, 6-methyl alkanes) and two of monocycloalkanes (cyclohexyl and cyclopentyl). The presence of members of the n-paraffin series between C11 and C26 inclusive was also confirmed by mass spectral data. The hydrocarbon content ranged from 6.7 to 82.8 ppm. Isoprenoids are present in all samples analyzed. Usually they show a major maximum at C19 (pristane) and a secondary maximum at C16 (methyl farnesane) with a minimum at C17.

Organic compounds in meteorites. V - Gas chromatographic-mass spectrometric studies on the isoprenoids and other isomeric alkanes in graphitic nodules of iron meteorites

Abstract Several specimens of graphite-troilite nodules from three different iron meteorites (Canyon Diablo, Odessa and Cosbys Creek) were studied following the same general techniques applied to the analysis of carbonaceous chondrites (Part III of this series). The results obtained in all cases are very similar to those obtained with the carbonaceous chondrites, although the amount of alkanes in the nodules is much lower, ranging from 0.32 to 9.36 ppm. These hydrocarbons show only a slight odd over even predominance except in one case, Cosbys Creek, where a marked odd predominance with a maximum at C15 is readily apparent from the gas Chromatographic pattern. A total of nine homologous series have been identified mass spectrometrically: the n-alkane series (C13–C26); the 2-, 3-, 4-, 6-methyl alkane series; the two isoprenoid series, 2,6,10-trimethyl and 2,6,10,14-tetramethyl alkanes (C16–C19 and C19–C21, respectively); and two series of monocycloalkanes (cyclohexyl and cyclopentyl). The isoprenoids were present in all of the meteoritic nodules analyzed with the same major maximum at C19 (pristane), the secondary maximum at C16 (methyl farnesane) and the minimum at C17. In several instances samples were taken from different parts of the nodules in order to study the homogeneity of the alkane distribution within the entire nodule. Invariably the inner parts had from three to seven times less alkanes than their surfaces, and the relative content of low molecular weight alkanes appeared to be higher inside of the nodule than at the exposed surfaces. Also, a significant increase in the amount of isoprenoids relative to the n-alkanes was observed in the inner portions of the graphite nodules. The presence and distribution of these types of compounds within the graphitic nodules embedded in the iron meteorites cannot be readily explained unless the contribution of extraneous material from the terrestrial environment is considered.

The ubiquity of hydrocarbons in nature: aliphatic hydrocarbons in dust samples

Abstract Aliphatic hydrocarbons ranging from C13 to C33 have been identified in dust. Isoprenoids and other isomeric alkanes have also been detected in some of the dust samples. The widespread occurrence of dust particles makes them a potential contaminant of extraterrestrial and geochemical specimens being analyzed for organic compounds.

Gas chromatographic-mass spectrometric analysis of isoprenoid hydrocarbons and fatty acids in shark liver oil products

The liver oil from the South American Basking shark has been fractionated by silica gel chromatography and analyzed by the new method of combined gas-chromatography mass spectrometry. The major compounds of the nonsaponifiable fraction are pristane and squalene, which account for 7.6 and 31.3% of the oil. The saponifiable fraction contains normal fatty acids from C14 to C22; the four major components are palmitic, oleic, and the monounsaturated eicosenoic and docosenoic acids. No correlation was observed between the hydrocarbons (essentially all isoprenoid derivatives) and the fatty acids (essentially all normal) of this oil.The same treatment was applied to a sample of commercial pristane which was obtained from Basking shark liver oil. It was found to contain about 1% phytane and small amounts of octadecane, nonadecane, and methyl and ethyl palmitates. Mass spectral data for squalene are presented for the first time along with the low electron energy-mass spectra for pristane and phytane.

Isoprenoids and other hydrocarbons in terrestrial graphite

Abstract Samples of terrestrial graphite from widely separated areas (e.g. Mexico, Ceylon, Madagascar) were found, with few exceptions, to contain extractable hydrocarbons. These hydrocarbons were classified into nonaromatic and aromatic fractions by silica gel chromatography and each fraction was analyzed by gas chromatography and combined gas chromatography-mass spectrometry. The nonaromatic fractions consisted primarily of straight chain alkanes and branched alkanes including C 14 through C 22 isoprenoids. The aromatic fractions were almost exclusively alkyl substituted naphthalenes.

Distribution modes and possible origins of sheep wool hydrocarbons

An unusual mode of distribution of low-molecular-weight n-alkanes (C11-C15) with a slight even carbon-number predominance has been observed in the gas Chromatographic analysis of the paraffin fraction which was extracted from the wool of live sheep. This is in addition to the other two modes of medium-, C15-C24, and high-, C24-C33, molecular-weight alkanes usually present in wool wax which have also been found in sheep’s manure. The high-molecular-weight hydrocarbons (predominantly odd carbon-numbered) are presumed to be derived from the diet (pasture plants) whereas the other two hydrocarbon distributions probably result from the combined action of animal and microbial metabolism.

Ubiquity of hydrocarbons in nature: Aliphatic hydrocarbons in weathered limestone

Abstract The aliphatic hydrocarbons in two specimens of limestone (one from Texas and the other from Italy) which were weathered in place as parts of building structures have been investigated using gas chromatography and gas chromatography-mass spectrometry. The hydrocarbons in 1. (i) the limestone from Texas and 2. (ii) algae cultured from this limestone have similar distributions, i.e. the predominating hydrocarbon in both cases is n-C17, thus indicating that most of the aliphatic hydrocarbons in the limestone may be derived from recent algal growth. The hydrocarbons in the limestone from Italy, in which n-C17 is a maximum but which also include relatively large amounts of pristane, phytane and other aliphatic hydrocarbons, appear to be a mixture of in situ biogenically derived hydrocarbons and extraneously derived fossil hydrocarbons.