José María de la Rosa

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The Viking missions showed the martian soil to be lifeless and depleted in organic material and indicated the presence of one or more reactive oxidants. Here we report the presence of Mars-like soils in the extreme arid region of the Atacama Desert. Samples from this region had organic species only at trace levels and extremely low levels of culturable(More)
The failure of Viking Lander thermal volatilization (TV) (without or with thermal degradation)-gas chromatography (GC)-MS experiments to detect organics suggests chemical rather than biological interpretations for the reactivity of the martian soil. Here, we report that TV-GC-MS may be blind to low levels of organics on Mars. A comparison between TV-GC-MS(More)
The production of pyrogenic carbon (PyC; a continuum of organic carbon (C) ranging from partially charred biomass and charcoal to soot) is a widely acknowledged C sink, with the latest estimates indicating that ~50% of the PyC produced by vegetation fires potentially sequesters C over centuries. Nevertheless, the quantitative importance of PyC in the global(More)
This work analyses the spatial distribution, the origin, and the shale-normalised fractionation patterns of the rare earth elements (REE) in the alluvial aquifer of the Guadiamar River (south-western Spain). This river received notoriety in April 1998 for a spill that spread a great amount of slurry (mainly pyrites) and acid waters in a narrow strip along(More)
Three pyrolysis biochars (B1: wood, B2: paper-sludge, B3: sewage-sludge) and one kiln-biochar (B4: grapevine wood) were characterized by determining different chemical and physical properties which were related to the germination rates and to the plant biomass production during a pot experiment of 79 days in which a Calcic Cambisol from SW Spain was amended(More)
The hepatotoxin cylindrospermopsin (CYN) is produced by freshwater cyanobacteria becoming an emerging threat for human health. Methods for the rapid determination of CYN in environmental samples are needed. Conventional analytical pyrolysis (Py-GC/MS) and thermally-assisted hydrolysis and methylation (TCh-GC/MS) were used to study a CYN standard, two(More)
A key goal for astrobiology is the search for evidence of life on Mars. Because liquid water is a fundamental environmental requirement for life, the recent set of missions to Mars have focused on a strategy known as "follow the water." Since life is made of organic molecules, a logical next step is "follow the organics." However, organics are expected to(More)
Biochar produced by pyrolysis of organic residues is increasingly used for soil amendment and many other applications. However, analytical methods for its physical and chemical characterization are yet far from being specifically adapted, optimized, and standardized. Therefore, COST Action TD1107 conducted an interlaboratory comparison in which 22(More)
Polyethylene is probably the most used plastic material in daily life and its accurate analysis is of importance. In this communication the chemical structure of polyethylenes is studied in detail using conventional analytical pyrolysis (Py-GC/MS), bulk stable isotopic analysis (IRMS) and pyrolysis compound specific stable isotopic analysis (Py-CSIA) to(More)
The effects of aging on biochar (BC) properties, composition and carbon sequestration are still under debate. This study aimed at illustrating the qualitative alterations of five different BCs aged during a 24-month field experiment located in Southwest Spain. To determine the recalcitrance of each BC, physical fragmentation test, scanning electron(More)