Phillip T. Crisp

Effect of pH on chromium(VI) species in solution.

Published values of equilibrium constants were used to calculate the percentage of each chromium(VI) species (CrO(4)(2-), Cr(2)O(7)(2-), HCrO(4)(-) and H(2)CrO(4)) present in aqueous solution at total chromium(VI) concentrations of 10(-2)-10(-6)M in the pH range 1-8.

Chemical characterization of shale oil from Rundle, Queensland

Abstract Pooled Fischer assay samples of shale oil from two seams in the oil shale deposit at Rundle, Queensland, were chemically separated into ten fractions and analysed by gas chromatography-mass spectrometry. Over 500 compounds were identified, including homologous series of straight-chain alkanes, 1-, 2- and 3-alkenes, nitriles, methyl ketones, amides and substituted cyclopentanes, cyclohexanes, benzenes, naphthalenes, pyridines and quinolines. The oils are highly aliphatic in character ( H C = 1.6 –1.7 ); alkanes (≈30 wt%) and alkenes (≈20 wt%) are the most abundant components in the oil, with the straight-chain alkanes and 1-alkenes predominating. The most highly aromatic fractions were found, by proton n.m.r., to be those which contain phenols and heterocyclic nitrogen compounds and which constitute less than 5% of the oil. Approximately half of the nitrogen in the shale oil was present as neutral nitrogen compounds such as aliphatic nitriles and amides. The carbon chain length distributions of the alkanes, nitriles and methyl ketones are bimodal indicating origins from both algal and higher-plant sources, with algal sources predominating. The pyrolytic origin of prominent and unusual components such as nitriles, amides, 1-alkenes and methyl ketones is discussed. This is the first detailed chemical analysis of an Australian shale oil.

Chemical characterization of shale oil from Condor, Australia

Fischer assay shale oil from the Condor oil shale deposit at Proserpine, Queensland, was chemically separated into 20 fractions and analysed by gas chromatography-mass spectrometry. Over 600 compounds were identified, including homologous series of linear alkanes, 2-methylalkanes, alkylcyclopentanes, alkylcyclohexanes, 1-, 2-, 3- and 4-alkanes, alkylcyclohexenes, alkylcyclopentenes, linear dienes, alkylbenzenes, alkylindans, alkylnaphthalenes, nitriles, 2- and 3-alkanones. Substituted cyclopentanes, cyclohexanes, benzenes, naphthalenes, polycyclic aromatic hydrocarbons, phenols, pyridines, dihyroindoles, quinolines and tetrahydroquinolines were also identified. The Condor oil is highly aliphatic in character (H/C=1.7), with alkanes (≈28%) alkenes (≈18%) alkadienes (≈2%) nitriles (≈11%) and alkanones (≈4%) being the most abundant components. The carbon chain length distributions of the alkanes, nitriles and methyl ketones (bi-, tri- and bimodal respectively) are indicative of both algal and higher plant sources with algal predominating.

Mutagenicity of metal ions in bacteria

The mutagenicity of 24 metal salts was investigated in plate incorporation and fluctuation assays with Salmonella TA strains or Escherichia coli WP2 uvrA pKm 101. Chromate(VI) and selenate(VI) ions were found to be mutagenic in plate incorporation assays employing conventional media. On the other hand, cadmium(II), beryllium(II), chromate(VI), and metavanadate(V) ions were detected in conventional fluctuation assays, indicating the importance of this technique in detection of metal mutagens. Modified culture media, with trimetaphosphate ions in place of orthophosphate as the sole phosphate source for bacterial growth, were also used in this study. The media modifications prevented precipitation of metals such as nickel and cadmium as their insoluble phosphates, and allowed detection of the mutagenicity of metavanadate ions in plate incorporation assays. However, the fluctuation technique using standard media was shown to detect a wider range of mutagenic metal ions than tests with modified media. It is notable that metaarsenite(III), arsenate(V), and nickel(II) ions were not found to be mutagenic in any of the assays although they are known to be carcinogenic and are mutagenic in other test systems. Their lack of mutagenicity in the modified media indicates that precipitation of these ions as orthophosphates is not the reason for their lack of activity in standard bacterial assays.

Application of X-ray photoelectron spectroscopy to the analysis of stainless-steel welding aerosols

Aerosol particles (“fume”) from manual metal arc welding of stainless steel with E316L-16 electrodes were analysed by X-ray photoelectron spectroscopy. The inherent complexity of the particles required the use of a wide range of experimental techniques. These included IR spectrophotometry, TGA/DTA, XRF, XRD, AAS and electron microprobe analysis. The surface of the fume particles comprised ≈ 50 at% NaF and KF, ≈ 8 at.% soluble (probably K) chromate, ≈ 30 at% SiO2 and several at.% transition-metal oxides, hydroxides or silicates. The fluorides and chromates were removed by washing to reveal a surface which was predominantly SiO2 (≈ 60 at%) with the remainder comprising of transition-metal oxides, silicates and fluorides. Approximately 6 at% F remained on the surface of the water-washed particles, presumably as transition-metal fluoro-complexes. The water-soluble fraction of the fume contained K+, Na+, F− and CrO2−4 ions in the mole ratio 5:5:4:3. When aerosol particles are deposited in lung tissues, water-soluble constituents would be expected to dissolve rapidly. In view of the suspected carcinogenicity of stainless steel welding fume, a bio-medical study of the combined effects of F− and CrO2−4 ions on lung tissue is warranted.

Pyrolysis of model compounds on spent oil shales, minerals and charcoal: Implications for shale oil composition

Abstract Aliphatic compounds (alkanes, alkenes, alkanoic acids, ketones, alcohols and amines) were passed through beds of spent oil shales (Condor brown, Condor carbonaceous, Julia Creek), minerals (quartz, calcite, K-feldspar, pyrite, kaolinite) and charcoal at temperatures of 300–600 °C and the products were analysed by g.c.m.s. All the materials catalysed isomerization, aromatization and cracking to varying degrees: non-clay minerals

The sampling of coke oven emissions for polycyclic aromatic hydrocarbons: a critical review

Abstract Polycyclic aromatic hydrocarbons (PAHs) are believed to be among the most harmful organic compounds emitted from coke ovens. Awareness of occupational health hazards is increasing and long-term monitoring of worker exposure to PAHs is becoming mandatory. We review the methods that have been used for sampling airborne PAHs at coke ovens, discuss the sources of sampling error and suggest the manner in which better sampling devices might be constructed. Sampling is usually performed by filtration (e.g. ‘benzene soluble fraction’ test) or by filtration followed by back-up collection using a solid adsorbent. Errors arise from incomplete trapping of material, evaporative losses, chemical degradation or incomplete recovery. We indicate the ways in which these errors may be minimized and point to areas where further work is required. Sampling is the most neglected stage in the analysis of airborne PAHs and new methods are required to satisfy the needs of industrial hygienists in the coking industry.

Chemical and pyrolysis characteristics of two types of oil shale from the Condor deposit in Queensland, Australia

Abstract The Condor oil shale deposit contains two major seams: a brown seam of almost pure lamosite origin and a black, or carbonaceous, seam of mixed lignite—lamosite origin. These differences in origin of the organic matter in the shale are reflected in their pyrolysis characteristics and particularly in the chemical composition of the oil retorted from them. The brown shale was found to have oil and gas evolution profiles similar to those reported for shales from the Green River (Colorado) deposit and to give a highly aliphatic oil containing vol .% of phenols. In contrast, the carbonaceous shale showed gas and oil evolution profiles resembling those of coal, and gave an oil high (≈ 10–15 vol . %) in phenols typical of coal pyrolysis products.

Determination of nitrogen compounds in hydrotreated shale oils by preparative high-performance liquid chromatography and gas chromatography—mass spectrometry

Abstract A simple two-step procedure has been developed for the isolation of trace nitrogen compounds remaining after hydrotreatment of shale oil. Open-column alumina chromatography quickly separates saturates plus monoaromatics from poly-aromatics and nitrogen compounds. The nitrogen compounds are then fractionated by preparative high-performance liquid chromatography using an amino bonded-phase column. Individual compounds may then be resolved and identified by gas chromatography—mass spectrometry. The procedure has been applied to whole hydrotreated shale oils prepared using catalysts of different activity and to four distillation fractions of a hydrotreated shale oil.

Chemical class separation of shale oils by low pressure liquid chromatography on thermally-modified adsorbants☆

Abstract Shale oils from Green River (USA) and Condor (Australia) were fractionated into compound classes by low pressure liquid chromatography on five columns in series containing successively less thermally-deactivated grades of alumina. No preliminary acidic and basic extractions were required, resulting in fewer polymeric artefacts than in other procedures. Irreversible adsorptive losses were minimized by the use of deactivated adsorbants and evaporative losses were minimized by the use of highly volatile solvents and small solvent volumes. Compounds identified include linear alkanes, isomeric linear alkenes, isoprenoid alkanes and alkenes, linear alkanonitriles, 2-, 3- and 4-alkenones, cyclopentanones, cyclohexanones, benzenes, styrenes, indans, indenes, 1-phenylalk-1-enes, naphthalenes, biphenyls, 3–5 ring aromatics, phenols, pyridines, quinolines, benzoquinolines, indoles, dihydroindoles and carbazoles. Particular compound classes may be isolated without performing a full chromatographic separation of all classes.