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Journal articleMuxworthy AR, Heslop D, Michalk DM, 2009,
Thermal fluctuation fields in basalts
, Earth, Planets and Space, Vol: 61, Pages: 111-117 -
Journal articlePerry RS, Sephton MA, 2009,
Reply to comments on defining biominerals and organominerals: Direct and indirect indicators of life [Perry et al., Sedimentary Geology, 201, 157-179]
, SED GEOL, Vol: 213, Pages: 156-156, ISSN: 0037-0738 -
Journal articleChristeson GL, Collins GS, Morgan JV, et al., 2009,
Mantle deformation beneath the Chicxulub impact crater
, Earth and Planetary Science Letters, Vol: 284, Pages: 249-257, ISSN: 0012-821X -
Journal articleCourt RW, Sephton MA, 2009,
Meteorite ablation products and their contribution to the atmospheres of terrestrial planets: An experimental study using pyrolysis-FTIR
, GEOCHIM COSMOCHIM AC, Vol: 73, Pages: 3512-3521, ISSN: 0016-7037 -
Journal articleGomes RL, Meredith W, Snape CE, et al., 2009,
Analysis of conjugated steroid androgens: Deconjugation, derivatisation and associated issues
, Journal of Pharmaceutical and Biomedical Analysis, Vol: 49, Pages: 1133-1140, ISSN: 0731-7085Gas chromatography/mass spectrometry (GC/MS) is the preferred technique for the detection of urinary steroid androgens for drug testing in athletics. Excreted in either the glucuronide or sulfated conjugated form, steroids must first undergo deconjugation followed by derivatisation to render them suitable for GC analysis. Discussed herein are the deconjugation and the derivatisation preparative options. The analytical challenges surrounding these preparatory approaches, in particular the inability to cleave the sulfate moiety have led to a focus on testing protocols that reply on glucuronide conjugates. Other approaches which alleviate the need for deconjugation and derivatisation are also highlighted.
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Journal articleSephton MA, Visscher H, Looy CV, et al., 2009,
Chemical constitution of a Permian-Triassic disaster species
, GEOLOGY, Vol: 37, Pages: 875-878, ISSN: 0091-7613One of the most controversial biological proxies of environmental crisis at the close of the Permian is the organic microfossil Reduviasporonites. The proliferation of this disaster species coincides with the mass extinction and numerous geochemical disturbances. Originally Reduviasporonites was assigned to fungi, opportunistically exploiting dying end-Permian forests, but subsequentgeochemical data have been used to suggest an algal origin. We have used high-sensitivity equipment, partly designed to detect interstellar grains in meteorites, to reexamine the geochemical signature of Reduviasporonites. Organic chemistry, carbon and nitrogen isotopes, and carbon/nitrogen ratios are consistent with a fungal origin. The use of this microfossil as a marker of terrestrial ecosystem collapse should not be merely discounted. Unequivocally diagnostic data, however, may have been precluded by post-burial replacement of its organic constituents.
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Book chapterMartins Z, Sephton MA, 2009,
Extraterrestrial amino acids
, Origins and Synthesis of Amino Acids., Editors: Hughes, Hughes, Weinheim, Publisher: Wiley-VCH, Pages: 3-42, ISBN: 9789783527324 -
Journal articleCourt RW, Sephton MA, 2009,
Quantitative flash pyrolysis Fourier transform infrared spectroscopy of organic materials
, Analytica Chimica Acta, Vol: 639, Pages: 62-66, ISSN: 0003-2670Thermal degradation is a common technique used to investigate the nature of organic materials. However, existing methods for the Fourier transform infrared (FTIR) identification and quantification of volatile products from the thermal degradation of organic materials are limited to the technique of thermogravimetric analysis (TGA)–FTIR, which utilizes relatively low heating rates. However, the thermal degradation products of organic materials are known to vary depending on the rate of heating, with lower heating rates of biomass associated with increased yields of solid char and decreased yields of volatiles, as well as a greater opportunity for secondary reactions between the residue and the pyrolysis products. Hence, it is difficult to relate the products of organic matter thermally degraded at <100 °C min−1 in TGA to the products of flash pyrolysis at up to 20,000 °C s−1. We have developed and applied a novel methodology for quantitative flash pyrolysis–FTIR analysis of the volatile pyrolysis products of organic-rich materials. Calibration curves of water, carbon dioxide and methane have been constructed and used to determine absolute volatile release from wood (ash, Lat. Fraxinus). This technique is quicker and simpler than comparable pyrolysis–gas chromatography–mass spectrometry techniques, and avoids errors associated with the lower rates of temperature increase associated with techniques such as thermogravimetric analysis.
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Journal articleHendry KR, Rickaby REM, de Hoog JCM, et al., 2008,
Cadmium and phosphate in coastal Antarctic seawater: Implications for Southern Ocean nutrient cycling
, MARINE CHEMISTRY, Vol: 112, Pages: 149-157, ISSN: 0304-4203- Author Web Link
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- Citations: 31
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Journal articlePierazzo E, Artemieva N, Asphaug E, et al., 2008,
Validation of numerical codes for impact and explosion cratering: Impacts on strengthless and metal targets
, METEORITICS & PLANETARY SCIENCE, Vol: 43, Pages: 1917-1938, ISSN: 1086-9379 -
Conference paperPaterson GA, Muxworthy AR, Roberts AP, et al., 2008,
Investigating the use of Pyroclastics for Palaeointensity Determinations (poster)
, AGU Fall -
Conference paperBarron LL, Williams W, Muxworthy AR, et al., 2008,
The Effect of Nanoscale Intergrowths on Palaeomagnetic Interpretations (poster)
, AGU Fall -
Journal articleOsinski GR, Grieve RAF, Collins GS, et al., 2008,
The effect of target lithology on the products of impact melting
, METEORITICS & PLANETARY SCIENCE, Vol: 43, Pages: 1939-1954, ISSN: 1086-9379 -
Conference paperMuxworthy AR, Heslop D, Paterson GA, et al., 2008,
Toward a new non-heating method of determining absolute paleointensities
, AGU Fall -
Journal articleBray VJ, Collins GS, Morgan JV, et al., 2008,
The effect of target properties on crater morphology: Comparison of central peak craters on the Moon and Ganymede.
, Meteoritics and Planetary Science, Vol: 43, Pages: 1979-1992 -
Journal articleCollins GS, Kenkmann T, Osinski GR, et al., 2008,
Mid-sized complex crater formation in mixed crystalline-sedimentary targets: Insight from modeling and observation
, METEORITICS & PLANETARY SCIENCE, Vol: 43, Pages: 1955-1977, ISSN: 1086-9379 -
Journal articleGrieve RAF, Reimold U, Morgan JV, et al., 2008,
Observations and interpretations at Vredefort, Sudbury and Chicxulub: Towards a composite model of a terrestrial impact basin
, Meteoritics and Planetary Science, Vol: 43, Pages: 855-882 -
Journal articleGenge MJ, 2008,
Koronis asteroid dust in Antarctic ice
, Geology, Vol: 36, Pages: 687-690 -
Journal articleMorgan JV, 2008,
Comment on "Determining Chondritic Impactor Size from the Marine Osmium Isotope Record"
, Science, Vol: 321, Pages: 1158-1158Paquay et al. (Reports, 11 April 2008, p. 214) report that Osmium isotope ratios in marine sediments can be used to determine the size of a chondritic impacting body. Their assumptions, however, on the fate of an impacting projectile are incorrect, as only a small, unpredictable fraction of the impactor ends up dissolved in seawater.
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Journal articleLiu Q, Yu Y, Muxworthy AR, et al., 2008,
Effects of internal stress on remanence intensity jumps across the Verwey transition for multi-domain magnetite
, PHYSICS OF THE EARTH AND PLANETARY INTERIORS, Vol: 169, Pages: 100-107, ISSN: 0031-9201- Author Web Link
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- Citations: 7
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