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Pyrolysis-compound specific isotopic analysis (Py-CSIA), is a relatively novel technique to measure stable isotope proportions i.e., ¿13C, ¿15N and ¿2H, ¿18O in individual compounds released by pyrolysis. This technique can provide valuable information on materials that are not soluble and therefore not amenable by conventional GC/MS techniques. The technique provides not only a molecular fingerprinting, but also allows the traceability of their formation processes and origin. At the MOSS Group Stable Isotope Laboratories (LIE-MOSS), direct pyrolysis compound specific isotopic analysis (Py-CSIA) is conducted using a double-shot pyrolyzer (Frontier Laboratories, model 3030D) attached to a Trace Ultra GC system. The flux is conducted to a GC-Isolink System equipped with micro-furnaces for combustion (carbon and nitrogen) and for pyrolysis (hydrogen or oxygen). The system is coupled to a Delta V Advantage IRMS via a ConFlo IV universal interface unit (Py-GC-C/TC-IRMS) (Fig. 1a). The identification of specific peaks (structural information) are inferred by comparing the mass spectra from a conventional Py-GC/MS system with the Py-GC/FID and Py- GC/IRMS chromatograms obtained using same chromatographic conditions (Fig. 1b). In this communication the general technical aspects and fundamentals of Py-CSIA will be presented as well as some recent examples of applications developed in our laboratories at the LIE-MOSS in different fields, including the food industries [2] and synthetic polymer industries [1] industry, research on fire/heat affected soil organic matter [3] and biomass and paleoclimate studies using fossil plant materials [4]. [1] JA. González-Pérez et al., J. Chromatogr. A. 1388, pp. 236-243, 2015. [2] JA. González-Pérez et al., J. Sci. Food Agric. In press, 2015. [3] NT. Jiménez-Morillo et al. In: A. Aizpurua Insausti et al. (Eds). CONDEGRES VII. 68-69. Neiker (ISBN: 978-84-606-9409-0), 2015. [4] JA. González-Pérez et al. In: communication to this congress PYRO 2016.

Fire is one of the most important drivers of soil organic matter (SOM) sequestration. In fact, accurate knowledge of wildfires’ effects on the SOM may provide information on its resilience and physico-chemical properties, as well as on the subsequent soil recovery without human intervention. While the quantitative assessment of fire damage levels on SOM is an issue of great interest to researchers, there is not general consensus on the reliability of the physical and chemical methods frequently used to provide surrogates on the real impact of the passage of fire on the soil. In fact, fire effect on soils depends on a complex interaction of factors (temperature, time, moisture, soil depth…) and in general, characterization of SOM samples from fire-affected ecosystems implies the use of several instrumental techniques. This work aims to provide reliable quantitative proxies for pyrogenic SOM in whole environmental samples, taking advantage from changes in hydrogen isotope ratios (δD) of specific compounds released by analytical pyrolysis (Py-CSIA). With this aim in mind, we carried out a series of controlled burnings of progressive intensity, under laboratory conditions, applied to dry samples of foliar biomass from a typical Mediterranean forest species (Juniperus thurifera) heated at 367 °C for different time periods (5', 5'30>, 6' and 7'). The results showed that isotopic analysis of up to 9 compounds (eicosanol, eugenol, stigmastan-3,5-diene, phenol, phenol, 2-methoxy-4-methyl, pimaric acid, limonene, hexadecenoic acid and methylabietate), common in all samples, allowed a valid assessment of the changes in the δD with the different times of burning. Pimaric acid was the only major compound that had a linear correlation y = 3.7x + 153.6 with a R2 = 0.9209, where y corresponds to δD and x is the burning time. The rest of compounds showed different behaviour with the progressive heating, with no defined trends: after the first heating stage, some compounds suffered depletion of the heavy isotope, others were not isotopically altered and others had slight deuterium enrichment (Fig. 1). Nevertheless, all compounds detected in samples subjected to the most intense heating suffered conspicuous deuterium enrichment. The change of isotope signature between control and sample that was burned for 5 min was high in several pyrolysis compounds; therefore, we need to continue the experiment within a broader range of burning times. Our results illustrate that the combination of analytical pyrolysis and isotopic analysis of specific compounds (PyCSIA) opens a new application for the quantification of fire damage levels, and also in the understanding of fire-induced structural changes in SOM, avoiding sample fractionation or wet chemical extractions. Fig. 1: Juniperus thurifera δD variations of 9 specific pyrolysis compounds through different heating periods at a constant temperature of 367 ºC.

The application of carbonized materials (including biochar and hydrochar) produced by the pyrolysis of biomass to soil has been proposed as a novel approach to establish a significant long-term sink for atmospheric carbon dioxide in terrestrial ecosystems [1]. In addition, several research studies pointed out that biochar can act as a soil conditioner enhancing plant growth by supplying and, more importantly, retaining nutrients, and by providing other benefits such as improving soil physical and biological properties [2]. Despite numerous authors take for granted that microbial degradation of carbonized materials is highly unlikely, this fact is far away from being true for all the chars. Nevertheless, the knowledge concerning the natural degradation of chars by microorganisms is of high interest due to the direct decline on the char capacity for C stabilization. In order to achieve this goal, biochars from different feedstock and pyrolysis conditions were applied to soil from a Calcareous Cambisol (0, 2.5 and 5%) which was filled into 30-cm long methacrylate columns. They were incubated during 4 months under controlled conditions (25 ºC, 12 hours of light per day and water holding capacity maintained at 60% by adding deionized sterile water). After 1 month of incubation, white colonies were observed on a biochar derived from paper-sludge. The microorganisms were cultured from paper sludge biochar, isolated and further identified by DNA-based molecular analysis [3]. The identified fungi grouped into the Fusarium genus within Ascomycota phylum, being represented by F. oxysporum. These fungi are soil-borne and have the ability to exist as saprophytes. F. oxysporum strains are known to degrade lignin and complex carbohydrates associated with soil debris [4]. However, many strains within the F. oxysporum are pathogenic to plants, especially in agricultural settings. Fusarium oxysporum f. sp. Cucumerinum is responsible for vascular wilt in cucumber plants [5]. These results are of significant interest for agriculture and demands microbiological tests prior to using biochar for increasing the carbon sequestration potential of soils or for agronomic purposes, since C stabilization and soil biological properties may be affected by specific biochars., References: [1] Lehmann J., Joseph S., 2009. Biochar systems. In “Biochar for Environmental Management: Science and Technology” (C. J. Lehmann and S. Joseph, Eds.), Earthscan, London. [2] Glaser B., Lehmann J., Zech W., 2002. Biol. Fert. Soils. 35, 219-230. [3] Saiz-Jimenez C., Miller AZ., Martin-Sanchez PM., Hernandez-Marine M., 2012. Environ. Microbiol. 14:3220-3231. [4] Rodriguez A., Perestelo F., Carnicero A., Regalado V., Perez R., De la Fuente G. Falcon M.A., 1996. FEMS Microbiol. Ecol. 21:213-219. [5] Scarlett K., Tesoriero L., Daniel R., Guest D., 2013. Eur. J. Plant Pathol. 137:315-324., The Marie Skłodowska-Curie actions (PCIG12-GA-2012-333784-Biocharisma project and PIEF-GA-2012-328689-DECAVE project), MINECO and the European Development Fund (Project PCGL2012- 37041) are thanked for the financial support.

Comunicación oral presentada en la European Geosciences Union General Assembly 2016 Vienna | Austria | 17–22 April 2016, Transformation of sewage sludge (SS) into char achieves sludge hygienisation, which is necessary prior its application into agricultural soils. The pyrolysis of SS increases its stability in a degree which depends on the thermal treatment used. Thus, chars produced by using hydrothermal carbonization are typically more stable than normal soil organic matter (SOM), but less stable than chars from dry pyrolysis (Libra et al., 2011). Addition of highlyrecalcitrant SS-chars to soil will likely increase its carbon sequestration potential; however the fertilizing properties of SS may be compromised due to its alteration during the pyrolysis. The main goal of this work was to investigate the biochemical recalcitrance of two 13C-enriched SS-chars once applied in a Mediterranean Cambisol as well as to evaluate their impact on the SOM quality and carbon stability. Thus, we studied the distribution of 13C between plants and soil after the addition of the 13C-enriched chars (2 atm%) to the soil. Therefore, we performed a greenhouse incubation experiment, using a Mediterranean Cambisol as matrix and tested the following treatments: control (soil alone), raw SS, SS-hydrochar, SS-pyrochar. The SS was produced in a pilot-scale waste-water plant and enriched with 13C by the addition of 13C-glucose during the treatment. The amendment was only applied to the upper 2 cm of the soil matrix where it accounted for 5% of its dry weight. Per pot, 25 seeds of Lolium perenne were sowed and incubated under controlled conditions. The biomass production as well as the concentration of 13C in leaves and roots was determined after 1, 2 and 5 months. The partitioning of the 13C between soil and plant and its transformation into bioavailable forms were monitored by stable isotopic mass spectrometry. The 13C-enrichment of the chars allowed the use of solid-state 13C NMR spectroscopy as a means for the detection of chemical alterations of the chars during their aging. - Libra J., Ro K., Kammann C., Funke A., Berge N., Neubauer Y., Titirici M., Fuhner C., Bens O., Kern J., Emmerich K. (2011) Hydrothermal carbonization of biomass residuals: a comparative review of the chemistry, processes and applications of wet and dry pyrolysis. Biofuels, 2 (1), 89-124.

Frenelopsis oligostomata (FR) is an extinct Cretaceous conifer adapted to severe water stress. Well preserved fossil remains found in marls from the Upper Cretaceous (Senonian c. 72 Mya) in Guadalix de la Sierra (Madrid, Spain) (Almendros et al. 1982) are studied using stable isotope analysis in bulk (C, H, O, N IRMS) and in specific compounds released by pyrolysis (C, H, Py-CSIA). Stable isotopic analysis of bulk samples was carried out in a Thermo-Scientific Flash 2000 HT coupled to a Delta V Advantage IRMS. Compound specific isotopic analysis (Py-CSIA) was conducted with a Frontier Labs Pyrolyzer (3030D) attached to a Trace GC Ultra chromatograph with a GC-Isolink System and via a ConFlo IV to a Delta V IRMS. Chemical structure of compounds was inferred by comparing classical electron impact mass spectra from Py-GC/MS with Py-GC/FID and Py-GC/IRMS chromatograms under the same GC conditions. Heavy bulk ¿13C values were found (-20.5±0.02 ¿) pointing to a depleted stomatal conductance and FR paleoenvironmental growth conditions of water and salt stress. Values obtained for ¿D (-101.9±2.2 ¿), ¿15N (10.7±0.2 ¿) and ¿18O (20.9±0.39 ¿) lay within those previously reported for fossil floras growing in warm environment and probably with very high evaporation rates. We were able to obtain ¿13C signatures for a number of biogenic compounds released by pyrolysis from FR (Py-CSIA including polysaccharides, lipids (Fig. 1 left), lignin methoxyphenols and altered lignin (alkyl benzenes and alkylphenols). Plant-air C fractionation in compounds derived from altered lignin for a C3 photosystem plant is c. ¿13C¿ 20.0 ¿ and considering a fractionation (c. ¿13C¿ ¿3.0 ¿) due to the plant depleted stomatal conductance conditions, we estimate that the atmospheric ¿13C value in the area during the Senonian epoch in c. ¿13C = ¿5.3±0.2 ¿. This indicates that FR grew on a 13C enriched atmosphere that could be caused by emissions of 13C to the atmosphere from warm and acidified oceans by volcanic depositions and/or net terrestrial C uptake with selective removal of light 12C isotope by plants. Also we were able to measure ¿D for alkyl series in the range C24¿C29 (¿D = ¿124.44±5.2¿) (Fig. 1 right). This value was taken as a proxy to infer the H isotopic signal of water in the area in the Upper Cretaceous, giving a value for palaeowater ¿D = ¿24.44±5.2¿. This indicates that 75 Mya our plant probably uptake deuterium enriched rain water that again points to warm growing environmental conditions.

6 páginas.-- 3 figuras.-- 2 tablas.-- 36 referencias, BACKGROUND: Pyrolysis-compound specific isotopic analysis (Py-CSIA: Py-GC-(FID)-C-IRMS) is a relatively novel technique that allows on-line quantification of stable isotope proportions in chromatographically separated products released by pyrolysis. Validation of the Py-CSIA technique is compulsory for molecular traceability in basic and applied research. In this work, commercial sucrose from C4 (sugarcane) and C3 (sugarbeet) photosystem plants and admixtures were studied using analytical pyrolysis (Py-GC/MS), bulk δ13C IRMS and δ13C Py-CSIA. RESULTS: Major pyrolysis compounds were furfural (F), furfural-5-hydroxymethyl (HMF) and levoglucosan (LV). Bulk and main pyrolysis compound δ13C (‰) values were dependent on plant origin: C3 (F, -24.65 ± 0.89; HMF, -22.07 ± 0.41‰ LV, -21.74 ± 0.17‰) and C4 (F, -14.35 ± 0.89‰ HMF, -11.22 ± 0.54‰ LV, -11.44 ± 1.26‰). Significant regressions were obtained for δ13C of bulk and pyrolysis compounds in C3 and C4 admixtures. Furfural (F) was found 13C depleted with respect to bulk and HMF and LV, indicating the incorporation of the light carbon atom in position 6 of carbohydrates in the furan ring after pyrolysis. CONCLUSION: This is the first detailed report on the δ13C signature of major pyrolytically generated carbohydrate-derived molecules. The information provided by Py-CSIA is valuable for identifying source marker compounds of use in food science/fraud detection or in environmental research. © 2015 Society of Chemical Industry © 2016 Society of Chemical Industry., This work has been partly funded by the Spanish ‘Ministerio de Economía y Competitividad’ through project GEOFIRE (CGL2012-38655-C04-01). Dr J.M. de la Rosa is the recipient of a fellowship from the JAE-Doc subprogram financed by the CSIC and the European Social Fund.

Galardonado por el comité científico de dicho congreso con el premio a la mejor contribución científica., Lava tubes are a type of volcanic caves formed when lava flows down along the slopes after the eruption of the magma. They develop as a hard crust on the surface of the basaltic lava flow due to rapid cooling, while inside the lava remains liquid. Secondary mineral deposits, or speleothems, mainly of siliceous composition have been reported on the walls and ceiling of many lava tubes [1, 2]. However, lava tubes have traditionally been considered of little interest from a mineralogical point of view and the studies devoted to those secondary mineral deposits are scarce. Cave corals or coralloid-like speleothems are found either on the basalt surface or on the surface of other speleothems. Hill and Forti [3] suggested that subaerial cave corals are generated by capillary-film water, whereas other authors attribute a microbially mediated origin to their formation [2]. Siliceous minerals are sometimes intercalated with carbonate minerals [4] due to the change in the chemical composition of supplying water, environmental changes of the surface area overlying caves and probable diagenesis. However, most of the literature devoted to cave corals merely describes its geology, morphology and mineralogy. The application of chromatographic techniques to the study of speleothems is scarce due to their low content of organic compounds and low volatility. This study comprises an innovative approach based in the combination of chromatographic and isotopic analyses, which were applied to characterize coralloid speleothems from the Ana Heva lava tube in Easter Island (Chile). Analytical pyrolysis combines GC/MS with pyrolysis and has become an important tool for the characterization of sediments [5]. In addition, this study takes advantage of Py-CSIA, a relatively novel technique in which the pyrolysate is directed through a combustion into an isotope ratio mass spectrometer (Py-GC-C/TC-IRMS) to measure stable isotope proportions i.e., ¿13C, ¿15N respectively of specific pyrolysis compounds. Figure 1. A) Coralloids, B) corresponding cross-section and C) Py-GC/MS at 500ºC of the three coralloid layers from Ana Heva lava tube. Pyrochromatograms of the three different layers of this coralloid speleothem were composed by alkyl benzenes, naphthalenes, n-alkanes and a few N-containing compounds, which are typical compounds from plant remains and microorganisms. Variations in ¿13C values suggested changes in water surplus. They suggest wetter conditions during the formation of the Ca-layer and a possible increase in the amount of incoming fluids from the covering andosol. The trend observed for ¿ 15N values could indicate an increase on the average temperature along the time, which is consistent with the so-called climate warming during the Holocene., Dr. J.M. de la Rosa and A.Z. Miller thank the ¿Biocharisma¿ (PCIG12-GA-2012-333784) and ¿DECAVE¿ (PIEF-GA-2012-328689) projects, respectively, funded by the Marie Curie Actions of the EC 7th Framework Programme. The Spanish Ministry of Economy and Competitiveness (project CGL2013-41674-P) and the European Social Funds are acknowledged for the financial support.

Fire is considered one of the main disturbing factors of ecosystems at global scale. Among other impacts, fire causes include physical and chemical changes on soil organic matter (SOM) (González-Pérez et al., 2004). One of the main consequences of burning is the formation of highly refractory material with a high degree of aromatization, black carbon (BC) (Hedges et al., 2000). The chemical composition of BC and the intensity of fire impacts on SOM depend strongly on fire conditions (De la Rosa et al., 2008). Therefore, the knowledge of the intensity and duration of temperature peaks is key to understand these processes (Davis, 1959). Nevertheless, in situ-determination is difficult. Burning experiments under laboratory conditions and traditional analytical techniques have provided hardly interpretable and contradictory results on temperature and time of heating. The main objective of this research is to study the relations between temperature and fire resilience with the chemical composition of fire-affected organic matter, through the combination of two new analytical techniques: [i] solid-state 13C-NMR spectroscopy and [ii] carbon isotope ratio mass spectrometry. To achieve this, litter samples were collected below the canopy of oaks (Quercus suber) in the Doñana National Park (SW Spain). Litter was air dried and heated at 250, 300 and 350 oC in a muffle furnace during different periods of time (5 and 15 minutes). Unburned air-dried litter samples were used as control. After heating, litter samples were analyzed using 13C-NMR spectroscopy and ¿13C ratio mass spectrometry. 13C-NMR analyses showed that increasing temperature and time of heating contributed to a decreased content of both O-Alkyl C compounds (60-110 ppm, carbohydrates) and lignin-derived compounds (45-60 ppm) and increased content of aromatic compounds (110-160 ppm). Litter samples heated at 350 oC during 15 minutes showed the highest aromaticity (65%). The progressive increase of aromaticity may be related to the degradation of thermolabile compounds, like polysaccharides, becoming highly aromatic compounds (Almendros et al., 2003; Baldock & Smernik, 2002). On the other hand, lignin defunctionalization may also be occurring, which also contributes to the formation of aromatic compounds (Knicker, 2007). ¿13C values showed no significant differences among treatments below 300 oC and 15 minutes of heating compared to the control. Above these thresholds, the carbon isotope composition showed a progressive depletion, reaching a value of -31.8 ¿ at 300 oC and 15 minutes of heating (5.4 ¿ lower than control). The temperature-induced 13C-depletion may be explained by a removal of compounds rich in heavy isotopes, such as those derived from carbohydrates, by condensation in compounds with a high degree of aromatization (Bird & Ascough, 2012) or both processes. After 13C-NMR and ¿13C experiments, the highest aromatization was observed in samples heated at 300 oC during 15 minutes. Both techniques showed that ¿13C composition changes only when the proportion of aromatic compounds exceeds the proportion of O-Alkyl C. These results suggest that, in the case of fires with medium-high temperatures and duration, the combined utilization of these techniques may be a powerful tool to approach temperature peaks and time of heating., his research is a result of the GEOFIRE (CGL2012-38655-C04-01) and POSTFire (CGL2013-47862-C2-1-R) projects, funded by the Spanish Ministry of Economy and Competitiveness.

Póster presentado en el la XVI Reunión Científica de la Sociedad Española de Cromatografía y Técnicas Afines (SECyTA2016) P‐ENV‐2, Eds: González-Pérez, José Antonio.-- Almendros Martín, Gonzalo.-- González-Vila, Francisco Javier.-- Rosa Arranz, José M. de la, Biochar may act as a soil conditioner, enhancing plant growth by supplying and retaining nutrients and by providing other services such as improving soil physical and biological properties. Different feedstock, such as organic waste derived from agriculture and forestry or urban wastes including sewage sludge, can be used for biochar production. Feedstock properties and production conditions will drive the properties and composition of produced biochars [1]. Special attention should be paid to polycyclic aromatic hydrocarbons (PAHs), these persistent organic pollutants are highly condensed aromatic structures formed during biochar production due to incomplete combustion (pyrolysis step) [2]. These PAHs may enter the environment when the biochar is applied as soil conditioner, thus the intention of this study was to test a potential hazardous impact due to the presence of PAHs in biochars. Two different PAHs extraction techniques were applied to evaluate the total and available PAHs content in biochars. In order to find a relationship between pyrolysis conditions, feedstock and abundance of PAHs, four biochars produced from different feedstock were analyzed. Three biochars were produced by technical pyrolysis (500‐600 ºC; 20 min) from wood, paper sludge and sewage sludge respectively (samples B1, B2 and B3). The fourth biochar was made from old grapevine wood provided by Bodegas Torres Company (Spain) and using the traditional carbonization method in kilns (kiln‐stack wood biochar; B4). A detailed characterization of these samples can be found in [3]. Exhaustive extraction: The total concentrations of the 16 US EPA PAHs were determined by extracting the biochars during 12h under continuum reflux with 100% toluene. Analysis of PAHs was carried out on an Agilent GC/MS 6890/5973i by on‐column injection of 1 μL of the extract. Chromatographic and mass spectrometric conditions applied are described in [1]. Non‐Exhaustive extraction: Cyclodextrins (CDs) have been proposed as alternative agents to enhance the water solubility of hydrophobic compounds. CDs have a low‐polarity cavity within which organic compounds of the appropriate shape and size can form inclusion complexes [4]. The selected CD was hydroxypropyl‐β‐CD (HPBCD), which has been widely used for this purpose in contaminated soils. ild extractions were performed using an 50 mM HPBCD solution as extractant containing 0.01 M Ca(NO3)2 as background electrolyte and 200 mg L−1 HgCl2 to prevent bacterial growth. Biochar samples (2 g) were placed in glass tubes containing 20 mL of extractant, and the tubes were placed on an orbital shaker at 100 rpm during 24 hours. Total PAHs yielded between 3167 (B3) and 6626 (B4) μg kg‐1. The PAHs concentration of B4 was a 50% higher than B1. Taking into account that both biochars (B1 and B4) are produced from wood, it can be concluded that the pyrolysis process of B4, which was produced by carbonization in traditional kilns, affected significantly the total PAHs levels. The non‐exhaustive extraction procedure resulted in closer abundances of PAHs, which ranged from 978 (B3) to 1585 (B1) μgkg‐1. These data pointed that c. 15‐35% of total PAHs present in biochars are extracted by CDs, and this amount could be considered as the fraction actually bioavailable. This parameter shoud be taken into account to determine the potential hazardous impact of the use of biochar as soil amendment., [1] J.M. De la Rosa et al., J. Soils and Sediments 16 (2016) 557‐565. [2] T. Bucheli et al. (eds) Biochar for Environmental Management (2nded.), Earthscan, London, UK. (2015) [3] J.M. De la Rosa et al., Science of the Total Environment 499 (2014) 175‐184 [4] H. Dodziuk, Cyclodextrins and Their Complexes: Chemistry, Analytical Methods and Applications. Wiley‐VCH Gmbh & Co. KGaA, Weinheim (2006)

Comunicación oral presentada en la European Geosciences Union General Assembly 2016 Vienna | Austria | 17–22 April 2016, Lava tubes, like other caves, contain a variety of speleothems formed in the initial stage of a lava tube formation or due to leaching and subsequent precipitation of secondary minerals. Primary and secondary mineral formations in lava caves are mainly composed of silicate minerals, although secondary minerals common in limestone caves have been also reported in this type of caves. In addition, unusual colored deposits have been found on the walls and ceilings of lava tubes, some of them of unknown origin and composition. A brown to black-colored mud-like deposits was observed in “Llano de los Caños” Cave, La Palma Island, Canary Islands, Spain. These black deposits coat the wall and ceiling of the lava tube where sub-horizontal fractures occur. FESEM-EDS, X-ray micro-computed tomography and mineralogical analyses were conducted for morphological, 3D microstructural and compositional characterization of these unusual speleothem samples. These techniques revealed that they are mainly composed of amorphous materials, suggesting an organic carbon composition. Hence, analytical pyrolysis (Py-GC/MS), solid-state 13C Nuclear Magnetic Resonance (NMR) and stable isotope analysis were applied to assess the nature and origin of the black deposits. The combination of these analytical tools permits the identification of specific biomarkers (di- and triterpenoids) for tracing the potential sources of the organic compounds in the speleothems. For comparison purposes, samples from the topsoil and overlaying vegetation were also analyzed. Chromatograms resulting from the Py-GC/MS showed an abundance of polysaccharides, lipids and terpenoids typically derived from the vegetation of the area (Erica arborea). In addition, levoglucosan, polycyclic aromatic hydrocarbons and N-containing heterocyclic compounds were detected. They probably derived from the leaching of charred vegetation resulting from a wildfire occurred in the area in 2012. The lack of the typical pattern of odd-over-even in the series of n-alkanes observed for the topsoil and black deposits has been recognized as an indication of fire. The 13C NMR spectrum of the black deposits showed a mixture of alkyl and O-alkyl compounds, carboxylic compounds and polysaccharides. Stable isotope analysis of δ 13C performed on the cave black deposits, topsoil and vegetation confirmed that the source of the organic fraction of the sample is a combination of partially charred vegetation (mainly Erica) and organic compounds from the andic soil over the cave. Therefore, these black deposits are the result of an input of plant organic matter and charred vegetation into the cave from rock fractures, which may constitute an important source of energy for cave organisms., the support from the Marie Curie Fellowships within the 7th European Community Framework Programme (Grants PIEF-GA-2012-328689-DECAVE and PCIG12-GA-2012-333784-Biocharisma respectively). The authors acknowledge the Spanish Ministry of Economy and Competitiveness (project CGL2013-41674-P) and FEDER funds for financial support.

Poster J.03 presentado en el The 40th International Symposium on Capillary Chromatography and 13th GCxGC Symposium May 29-June 03, (2016) Riva del Garda Fierecongressi, Riva del Garda, Italy, isotopic analysis (Py-CSIA) and analytical pyrolysis (Py-GC/MS) opens new windows of information and is particularly useful to study solid materials that are not soluble and therefore not amenable by conventional GC/MS techniques. Py-CSIA is a rather novel hyphenated technique that combines the chromatographic separation of compounds released by pyrolysis (Py-GC) with an isotope ratio mass spectrometer (IRMS). The technique allows the measurement of stable isotope proportions i.e., δ13C, δ15N and δ2H, δ18O in specific compounds released by pyrolysis. The sample preparation is minimized and a molecular fingerprinting of the material is achieved.

4th European biochar winter school. Biochar applications: current developments and future perspectives” Palermo (Italy), 9-12 February 2016

Póster presentado en la XVI Reunión Científica de la Sociedad Española de Cromatografía y Técnicas Afines (SECyTA2016) P‐ENV‐20, Eds: González-Pérez, José Antonio.-- Almendros Martín, Gonzalo.-- González-Vila, Francisco Javier.-- Rosa Arranz, José M. de la, wildfire is a frequent environmental perturbation in Mediterranean ecosystems, which severely affects physical and chemical soil properties. In particular, the composition and properties of soil organic matter (SOM) are those experiencing the most important transformations. In the short term, most fire‐induced alterations frequently contribute to the loss of soil quality and productivity. For these reasons, post‐fire soil management requires local information about the natural post‐fire evolution of the different soil types. Most recent studies have focused on the effects of fire in SOM composition, but research about progressive changes in the course of the restoration is scarce. In August 2012, a wildfire affected a forest area of ca. 90 ha in Montellano (Seville, SW Spain). The predominant vegetation consisted of Pinus pinaster, Pinus halepensis and Eucalyptus globulus. Soil samples were collected 1 month and 25 months after the fire. Sixteen months after the post‐fire rehabilitation practices. The analysis of SOM molecular composition was one using analytical pyrolysis (Py‐GC/MS), i.e., a versatile on‐line analytical facility which requires no sample pretreatment. Pyrochromatograms of whole soil samples collected 2 years after the fire showed that SOM was still altered by fire, i.e., soil couldn’t be considered as restored. The evolution was illustrated by an improved Van Krevelen’s graphical‐statistical method, where the fire damage levels—or the soil recovery status—were visually compared as surface density plots in the space defined by compound‐specific atomic H/C and O/C ratios of the Py‐GC/MS molecules, either as autocumulative total abundances, or after subtracting the values at the different stages of the chronosequence. Our results indicate that rehabilitation practices carried out after the fire, which included the removal of burnt vegetation, far from helping soil recovery may have resulted into delayed soil recovery. In addition, the mechanical disruption of topsoil by heavy machinery used enhanced erosion risks. Analytical pyrolysis could be an important tool for the continuous monitoring, at a molecular level, of SOM evolution with time.

Moonmilk has been reported in subterranean environments worldwide. This term refers to carbonate deposits with pasty cheese like texture (Fig. 1), but with different origins and mineralogical composition. Generally, moonmilk deposits are found in carbonate caves, and are composed of calcite, hydromagnesite, aragonite, vaterite or huntite. The calcite that forms moonmilk is frequently observed as needle-shaped and its origin is a controversial issue. It is questionable whether the precipitation of calcite is induced by microorganisms, by abiotic physicochemical processes, or even a combination of both. The application of chromatographic techniques to study cave speleothems is scarce due to their low content of organic compounds and low volatility. Analytical pyrolysis (Py-GC/MS) is particularly useful to study materials that are not soluble and therefore not amenable by conventional GC/MS techniques. In this study, Py-GC/MS was applied for assesing the origin of organic compounds associated with moonmilk deposits from a lava cave in La Palma Island (Canary Islands, Spain; Pyrolysis of the moonmilk deposits were carried out at 500ºC. The chromatograms showed the presence of different organic compounds: fatty acids (mainly C16, C18; C18:1 and C28), pyrolysis products derived from polysaccharides (levoglucosan), phytosterols and steroids (stigmasterol, β-sitosterol, cholest-5-en-3-ol, stigmastan-3,5-diene, stigmasta-3,5-diene-7-one), triterpenoids of the oleanane (28-norolean-17-en-3-one, β amyrin), as well as ursane series. These compounds, including specific triterpanes and steranes, have been previously found in sedimentary records. They are believed to be derived from oxygenated triterpenoids in angiosperms, comprising the most common steroids in the epicuticular waxes of higher plants and are widely distributed among the plant kingdom. These data suggest that the organic compounds associated with moonmilk from La Palma Island lava cave are partially driven by the topsoil and overlying vegetation, thus demonstrating the potential use of moonmilk in palaeoenvironmental research.

Speleothems, or secondary mineral deposits in caves, are usually formed due to the dissolution of primary minerals from the host rock, such as in limestone and dolostone caves. In volcanic caves, the vast majority of speleothems are siliceous, formed in the initial stage of lava tube formation or due to leaching and subsequent precipitation of secondary minerals [1]. Among them, organic ooze deposits that coats the walls of lava tubes have been reported [2,3]. In a lava tube (Llano de los Caños Cave) from La Palma Island, in Canary Islands (Spain), black ooze with honey-like scent was collected from the wall and ceiling of the cave where sub-horizontal fractures occur (Fig. 1A,B). Field emission scanning electron microscopy (FESEM-EDS), X-ray micro-computed tomography (micro-CT) and mineralogical analyses were conducted for characterizing the surface morphology, 3D microstructure and mineralogical composition of these black organic deposits. Abundant microbial structures were found in close association with the organic ooze, including reticulated filaments (Fig. 1B), bacterial cells, platelet microorganisms and pollen grains (Fig. 1B). The overall volume of the sample showed low opacity or high transparency to X-rays according to micro-CT (Fig. 1C), with the exception of a superficial deposition of calcium carbonate in the form of calcite (whitish layer), as also observed by stereomicroscopy (Fig. 1B, white particles). The X-ray pattern showed a broad hump typical of non-crystalline material and some calcite, suggesting that the black ooze samples are mainly composed of amorphous material and calcite. In an attempt to achieve an accurate characterization of the ooze deposits found in Llano de los Caños Cave in La Palma Island and unveil the nature of these unusual honey-like scented deposits, analytical pyrolysis (Py-GC/MS) and stable isotope analysis were performed. Py-GC/MS showed abundance of polysaccharides, plant lipids and specific terpenoids typical of the local vegetation (mainly Erica arborea). In addition, polycyclic aromatic hydrocarbons and N-containing heterocyclic compounds were detected, which probably derived from the leaching of charred vegetation resulting from a wildfire occurred in the area in 2012. Stable isotope analysis of δ 13C, performed on the cave black deposits, topsoil and Erica arborea collected from the area over the lava tube, confirmed that the organic fraction of the ooze deposits are a combination of partially charred vegetation and organic compounds from the andic soil located over the cave. Therefore, these cave deposits are the result of an input of plant organic matter and charred vegetation into the cave through rock fractures, which may constitute an important source of energy for cave organisms. The honey-like scent of the black ooze deposits is probably due to the thermal transformation of abundant plant polysaccharides during fire and their subsequent deposition on the cave wall, AZM and JMR acknowledge the support from the Marie Curie Fellowships within the 7th European Community Framework Programme (Grants PIEF-GA-2012-328689-DECAVE and PCIG12-GA2012-333784-Biocharisma respectively). The authors acknowledge the Spanish Ministry of Economy and Competitiveness (project CGL2013-41674-P) and FEDER funds for financial support.

Póster presentado en el la XVI Reunión Científica de la Sociedad Española de Cromatografía y Técnicas Afines (SECyTA2016) P‐ENV‐5, Eds: González-Pérez, José Antonio.-- Almendros Martín, Gonzalo.-- González-Vila, Francisco Javier.-- Rosa Arranz, José M. de la, Speleothems, or secondary mineral deposits found in caves, are formed due to dissolution of primary minerals from the host rock and subsequent precipitation. Their formation is greatly prompted by water‐rock interactions and climate conditions, which dictate how much water drip into the cave system [1]. In humid climates or during heavy precipitation a relatively rapid speleothem growth may occur, whereas in arid climates or during drought the growth is moderated or ceased. Hence, the composition, abundance and growth pattern of speleothems may be indicative of climate changes, as reported by several authors [1‐2]. This study comprises a multidisciplinary approach based in the combination of chromatography (analytical pyrolysis and pyrolysis compound‐specific isotope analysis) and stable isotope analysis for characterizing organic compounds entrapped in speleothems from volcanic caves. Samples collected in lava tubes were selected for this study: (i) coralloid speleothems rrom Easter Island (Chile), and (ii) moonmilk deposits from La Palma (Canary Islands, Spain). The aim was to recognize environmental changes during speleothem formation. The coralloid speleothems from Easter Island consisted of three major layers with different mineralogical composition and a significant contribution of organic carbon. Analytical pyrolysis (Py‐GC/MS) revealed contributions from higher plants and microorganisms to the organic matter entrapped in the coralloid speleothems. Biogeochemical analyses based on isotopic signatures and pyrolysis compound‐specific isotope analysis (Py‐CSIA) revealed that the genesis of the three colored layers was related to two different stages of speleothem formation caused by environmental changes on Easter Island. Variations in δ13C values pointed to wetter conditions during the formation of the innermost layer and a water shortage during the latest stage of speleothem formation. The trend observed for δ15N values suggested an increase in theaverage temperature over time, which is consistent with the so‐called climate warming during the Holocene [3]. The chromatograms of the moonmilk deposits from Canary Islands evidenced the presence of organic compounds in their composition, in particular fatty acids, polysaccharides, phytosterols and oleanane‐type triterpenes. Most of them have been previously found in sedimentary records. Oleananes and specific steranes are believed to derive from the early diagenesis of gymnosperms [4]. Our data suggest that the organic compounds associated with moonmilk deposits are partially driven by the topsoil and vegetation overlying the cave system. Hence, Py‐GC/MS and Py‐CSIA could be used as a valid proxy for paleoenvironmental research., [1] J.M. Calaforra, P. Forti, A. Fernándes‐Cortés, Environ. Geol. 53 (2008) 1099–1105. [2] A. Moreno, H.M. Stoll, M. Jiménez‐Sánchez, I. Cacho, B. Valero‐Garcés, E. Ito, R.L. Edwards, Global Planet. Change 71 (2010) 218–231. [3] A.Z. Miller, J.M. de la Rosa, N.T. Jiménez‐Morillo, M.F.C. Pereira, J.A. González‐Pérez, J.M. Calaforra, C. Saiz‐Jimenez, J. Chromatogr. A (2016) in press. [4] J.O. Grimalt, I. Yruela, C. Saiz‐Jiménez, J. Toja, J.W. DeLeeuw, J. Albaiges, Geochim. Cosmochim. Ac. 9 (1991) 2555–2577.

Los biosólidos se emplean en agricultura con un doble propósito. Por una parte disminuir la cantidad de residuos orgánicos depositados en vertederos y por otra aportar nutrientes y mejorar las condiciones agronómicas del suelo. Biochar es el producto que resulta de la degradación térmica de biomasa en ausencia de oxígeno. Este proceso se conoce como pirólisis. En los últimos años se han estudiado los efectos de transformar los residuos orgánicos en biochar mediante distintas técnicas de pirolización. En relación a los biosólidos, la pirólisis húmeda se ha considerado como un tratamiento alternativo a los ya establecidos para higienizar y estabilizar este material. Sin embargo, es necesario evaluar si esta técnica conserva las propiedades beneficiosas para el suelo y los cultivos que contienen los lodos originales. El objetivo principal de este estudio fue determinar los cambios que experimentan los biosólidos, relacionados con su potencial agronómico, al someterlos a pirolisis húmeda. Para ello: i) Lodos procedentes la planta experimental de Carrión de los Céspedes (Sevilla) se pirolizaron mediante pirólisis húmeda. Se aplicaron dos tiempos de residencia en el reactor (30 min y 1 h) y dos temperaturas (200 y 260°C) diferentes; ii) se caracterizaron los lodos pirolizados (LPy). Para ello se midió su contenido en Carbono, Nitrógeno, pH, contenido en materia orgánica, nutrientes disponibles, contenido en metales pesados e hidrocarburos aromáticos policícliclos; iii) se evaluó la germinación y crecimiento de Lolium perenne en un suelo típico del área Mediterránea (Cambisol) enmendado con estos LPy mediante un experimento de incubación. Los lodos pirolizados a menor temperatura presentaron características más adecuadas para su uso como enmienda orgánica en suelos que aquellos pirolizados a 260°C. La aplicación de LPy en el Cambisol disminuyó la tasa de germinación de Lolium perenne en comparación con el control, pero aumentó significativamente la producción de biomasa total por maceta., Los autores agradecen al Ministerio de Economía y Competitividad (MINECO, Gobierno de España) y al programa Marie Curie Intregration Fellowships de la Unión Europea por la financiación de los proyectos PCGL2012-37041, PCIG12-GA-2012-333784 y CGL2015-64811-P. Se agradece al Ministerio de Educación y Cultura (Gobierno de España) la financiación de la beca FPU (FPU 13/05831) de Dña. Marina Paneque

Natural and prescribed vegetation fires lead to the input of considerable amounts of charcoal into soils. This amount will even increase by the application of biochar as a tool to improve soil fertility. Whereas it is well accepted that an immediate effect of charcoal input represents the enhancement of the aromaticity of the soil organic matter (SOM) in particular of the topsoils, our knowledge about the long-term impact of this material on the humification processes is still scarce. Therefore, the present review intends to outline this issue by complementing present knowledge with results of our recent studies. Analyzing the organic matter along profiles of typical soils in Brazil which were frequently exposed to fire since decades and even centuries revealed the presence of charcoal residues down to the C horizons. Interestingly, lower charcoal contributions were found in the topsoils than in the deeper horizons. Comparable results were obtained for fire-affected soil of the Mediterranean region. Most tentatively, charcoal was efficiently oxidized and biodegraded at the surface turning it into a more humus-like substance. However, as revealed by solidstate NMR spectroscopy, some of the degradation products must have been transported into deeper soil regions where they were selectively preserved. Possibly, the oxygen depletion in subsoils or the interaction of oxidized PyOM with the mineral phase has increased its biochemical recalcitrance resulting in a preferential degradation of SOM derived from fire-unaffected sources. Our data clearly show that frequent charcoal addition can have a higher long-term impact on SOM of deeper soil horizons than commonly assumed. It may even represent an essential factor for defining the properties of such subsoil. Considering further that oxidized charcoal residues may also leach into the aquifer, a further evaluation of the impact of such residues on the groundwater is urgently needed.

12 pages, 3 figures, 4 tables, 44 references., The bio-geographical significance of Rhododendron ponticum spp. baeticum (Ericaceae) as a relict species is well recognized. However, out of its native habitat it is an invasive exotic considered a major threat to natural ecosystems in areas of Atlantic Western Europe. The studies on the impact of Rhododendron influence on soil organic matter composition and associated ecological implications, i.e. presence of bioactive compounds with ecological significance, are limited. This work describes the soil lipid assemblage in three sites under Rhododendron stands and adjacent sites with deciduous oak (Quercus canariensis), both in their native habitats in Southern Spain (Sierra de Luna, Ca´diz). The results are discussed in terms of organic matter dynamics and the presence of molecules that may be associated with Rhododendron invasive success. The soils are acid Xerochrepts formed on siliceous sands. Composite soil samples were taken at two depths (0–10 cm and 10–20 cm) and soxhlet extracted with a dichloromethanemethanol mixture (3:1). Soil lipid assemblage was studied by GC/MS after fractionation and appropriate derivatization of extracts. The qualitative chemical composition of soil extractable lipids under Rhododendron is reported here for the first time. Our results show that soil n-alkane and fatty acid distributions are compatible with an input from plant epicuticular waxes, as well as with the occurrence of selective preservation of long-chain fatty acids with depth. The pattern of short-chain n-alkanes found in surface samples indicates an anthropogenic contamination threat from nearby industrialized areas of ‘‘Campo de Gibraltar’’. The presence of branched iso and anteiso C15 and C17, b-hydroxy fatty acids and the sterol brassicasterol points to high microbial soil activity. Finally, the pentacyclic triterpenes taraxerone and taraxerol were detected in soils with Rhododendron but not with Quercus. These are known bioactive plant compounds and could be related with the effectiveness of Rhododendron as an invasive exotic species.

9 pages, 3 figures, 5 tables, 45 references., Black carbon (BC), presenting the residue from incomplete combustion processes of fossil fuels and vegetation, has received special interest as a possible carbon sink in soils and sediments. In spite of this, there is still a need to develop accurate and comparable analytical protocols to determine the amount of BC stored in different environmental matrices and to characterise potentially interfering materials in the analysis of BC. Therefore in this study a melanoidin, a sample from the Green River Shale, a lignite and a bituminous coal were characterised by means of elemental analysis, thermogravimetry–differential scanning calorimetry (TG–DSC), pyrolysis coupled with gas chromatography–mass spectrometry (Py-GC/MS) and 13C NMR spectroscopy. Thermal analysis (TG–DSC) indicated larger contributions of labile OM in the melanoidin and in the shale samples than in the lignite and the bituminous coal, although the coals showed an intense exothermal peak at temperatures higher than 550 °C. This behaviour is in agreement with high thermal recalcitrance of the latter and was also found in earlier studies of BC-rich material. Comparable to the latter, Py-GC/MS of the coals reveals considerable amounts of lignin-derived products. This and the similar thermal behaviour of both refractory materials aggravate their discrimination during BC-analysis. The pyrogram of the melanoidin reveals an important contribution of furanes and pyrane-like structures that derive from carbohydrates. NMR spectroscopy supports that those compounds are original constituents of the melanoidin rather than solely pyrolysis products. Considering that those compounds are typically formed during charring of N-containing biomass, their contribution to the BC structure should not be neglected if one seeks for a better understanding of BC structuralproperties. For the shale sample, both analytical pyrolysis and 13C NMR spectroscopy confirm a high contribution of long alkyl-C chains. Due to their high hydrophobicity such structures can stand chemical oxidation and their presence in soil and sediment samples can obscure BC quantification by those methods. This study indicates that present approaches for BC-identification that are based on the assumption of BC being mostly a highly condensed polyaromatic network, have to be taken with caution and modified in accordance with a more heterogeneous composition of BC containing considerable fractions of only partly charred biopolymers., The Spanish Ministry of Education provided a fellowship to J.M. de la Rosa for this research (BES-2003-1900). We acknowledge support from the Royal Society (Joint Project 2005/R3-JP) and CSIC (Proyectos Conjuntos 2005GB0098).

Wildfire is a frequent ecological phenomenon in Mediterranean ecosystems, which usually affects the physical and chemical properties of soils, and frequently contribute to the loss of soil quality and productivity. Soil erosion risk and lost of habitat of species are also two of the most usual consequences of wildfires. In particular it has been widely documented the quantitative and qualitative changes in soil organic matter (SOM) occurred during a wildfire. For these reasons, the post fire soil management needs to be addressed with caution to avoid further damages. In August 2012, a wildfire affected a forest area of approx. 90 ha in Montellano (Seville, SW Spain; longitude 37.00 º, latitude -5.56 º). The typical species in this area are Pinus pinaster, Pinus halepensis and Eucaliptus globulus. The dominant soil type in this zone is a Calcaric Haplic Regosols. Burnt trees and plant residues were removed from the fire affected area 16 months after the fire using heavy machinery. Soil samples were taken at different depths (0-1, 1-5, 5-10, 10-15 cm) 1 month and 25 months after the wildfire. Control samples were collected in an un-affected neighbour area with similar physiographic conditions. The elemental analysis of the soil samples showed that total organic carbon (TOC) content increased on the top layer in the burnt soils sampled 1 month after the fire event. However, TOC and total nitrogen contents decreased 25 months after the fire in the burnt soils. The same was observed concerning the water holding capacity (WHC). In this case, fire caused a reduction of the WHC in the section at 1-5 cm depth. The pH of the burnt topsoils increased, probably due to the presence of ashes. 25 months after the fire, burnt and unburnt topsoil showed similar pHs, whereas the increase in pH was transferred to deeper soil sections, which is probably related with the leaching of ashes. Soil samples were analysed by analytical pyrolysis (Py-GC/MS) and 13C NMR spectroscopy. The results showed enrichment in aromatic compound in the burnt samples, which was still apparent 25 months after the fire. The increased of aromaticity due to charcoal was confirmed by 13C NMR spectroscopy. Analytical pyrolysis showed a reduction in the relative abundance of fatty acids in the burnt soils, which was more pronounced in the second sampling. The average chain length (ACL) of n-alkanes as well as n-alkenes decreased after the fire probably due to the thermal cracking of the longer homologues. Nevertheless, the samples taken 25 months after the wildfire revealed similar ACL values. In conclusion, fire induced changes in the SOM composition, which may increase the erosion risk. The used of heavy machinery has probably contributed to slow down the possible soil recovery. Nowadays, the vegetation is still very scarce at the burnt area and the loss of soil material and alteration of SOM composition seems to continue. Nevertheless, information from the most recent sampling suggest that factors other than fire, 61 such as hot and dry periods followed by episodes of heavy rain are contributing to the SOM alteration., Málaga, 19-21 de noviembre de 2015

Poster presentado en el 2º course of The Stable Isotope course was performed October 5-9 Seville (Spain). (2015), Pyrolysis-compound specific isotopic analysis (Py-CSIA), is a relatively novel technique to measure stable isotope proportions i.e., δ 13C, δ 15N and δ 2H, δ 18O in specific compounds released by pyrolysis. This technique can provide valuable information on natural and synthetic materials that are not soluble and therefore not amenable by conventional GC/MS techniques. The technique provide not only a molecular fingerprinting, but also allowing the traceability of their formation processes and origin. Here we made a brief summary of examples of Py-CSIA applications recently developed in our laboratories in different fields, including the food and synthetic polymer industry, research on fire/heat affected soil organic matter and biomass and paleoclimate studies using fossil plant remains., The work described here was in part financed by projects GEOFIRE (CGL2012-38655-C04-01) and CSIC10-1E-448 funded by the Spanish Ministry for Economy and Competitiveness and CSIC. N.T Jiménez-Morillo is funded by a FPI research grant (BES-2013-062573) and by EBD registration grant to attend this course. Dr. J.M. de la Rosa thanks “Biocharisma” project (PCIG12-GA-2012-333784) funded by the Marie Curie Actions of the EU 7th Framework Program.

In the Mediterranean basin forest fires are considered among the main disturbance factors and are the cause of both immediate and lasting environmental impacts. This is in part caused by the transformation of soil physical, chemical and biological characteristics associated to changes in soil organic matter (SOM); the most reactive and functional soil fraction (González-Pérez et al., 2004, 2008 and references therein). In this communication the effect of wildfire in SOM isotopic signature is analysed in an experiment comparing fire-affected and nearby nonaffected sites. The soil type was an Arenosol (WRB 2006) in a Mediterranean climate (Doñana National Park, Andalusia, SW Spain) with cork oak (Quercus suber) as the main vegetation cover. Whole soil samples (composite samples from 4 replicates) taken under the canopy of cork oak stands and different size fractions (sieving) were studied. The fire event was severe and occurred in the summer of 2012. Carbon stable isotopic analysis (δ13C IRMS) of bulk samples (whole soil and particle-size fractions) was carried out in a Thermo-Scientific Flash 2000 HT elemental micro-analyser coupled to a continuous flow Delta V Advantage isotope ratio mass spectrometer (IRMS). Direct pyrolysis compound specific isotopic analysis (PyCSIA) of carbon (δ13C) and hydrogen (δD) was also conducted with a double-shot pyrolyzer (Frontier Laboratories, model 3030D) attached to a Trace Ultra GC system. At the end of the chromatographic column and in order to locate specific peaks within the chromatogram, the flux was divided and 10% diverted to the flame ionization detector (GC/FID) and 90% to a GC-Isolink System equipped with a micro-furnace for combustion (EA) and coupled via a ConFlo IV universal interface unit to the Delta V Advantage IRMS (Py-GC-(FID)-C-IRMS). The identification of specific peaks were inferred by comparing mass spectra from conventional Py-GC/MS (data not shown) with Py-GC/FID and Py-GC/IRMS chromatograms obtained using the same chromatographic conditions., Projects CGL2012-38655-C04-01 and CGL2008-04296 and fellowship BES-2013-062573 given by the Spanish Ministry of Economy and Competitiveness to N.T.J.M. Dr. J.M.R. is the recipient of a fellowship from the JAE-Doc subprogram financed by the CSIC and the European Social Fund

Nowadays, EU countries produce more than 10 million tonnes of dried sewage sludge (SS) per year (Laturnus et al., 2007). This residue is rich in N, P and other micronutrients, which may turn it into a useful fertilizer, if subsequent pollution with heavy metals and pathogens can be avoided. Pyrolysis of this material prior to its land application can help to eliminate such pathogens and may have an additional benefit to increase the carbon sequestration in soils after its application. The main goal of this study was to determine the conditions for the hydrothermal carbonization of sewage sludge which are the most beneficial for the plant growth on a typical soil of the Mediterranean area. The hydrochars derived from sewage sludge collected from the Experimental Wastewater Treatment plant CENTA (http://www.centa.es/), located near Seville, Southern Spain. Hydrothermal carbonization was carried out at 200°C and 260°C with residence times of 30 min and 1h. They were used as soil amendment in a greenhouse incubation study which was carried out for 80 days using a Calcic Cambisol (IUSS Working Group WRB, 2007) and an amount of hydrochar equivalent to 5 and 25 t ha-1 (n = 4). Control pots, without hydrochar addition, were also settled (n = 4). In each pot, 25 seeds of Lolium perenne were planted and their germination, the survival rate and biomass production of the plants per pot were measured periodically. In addition, a characterization of the hydrochars was carried out to determine their main chemical and physical properties as well as the presence of heavy metals and organic pollutants. Although hydrochar amended pots exhibited lower germination rates than the unamended pots, the total biomass production per pot raised significantly for all tested hydrochars. The first may be due to the presence of and PAHs in the hydrochars. Whereas hydrochars produced at 260°C resulted in a significantly higher amount of harvested plant biomass than those heated at 200°C, the residence time of the hydrochars in the reactor had no impact on plant growth. The higher nitrogen amount of the hydrochars produced at 200¿C compared to those produced at 260¿ may explain the better effect on plant growth of the former compare to the latter. Hydrothermal carbonization of sewage sludge at 200¿C, regardless the residence time, seems to be the most suitable production conditons for Lolium perenne growth. In addition, a washing with water and acetone of the hydrochar before its use may be appropriated to avoid the decrease in the germination rate observed. Laturnus F, von Arnold K, Grøn C (2007). Organic Contaminants from Sewage Sludge Applied to Agricultural Soils. Env Sci Pollut Res 14, Special Issue 1, 53¿60

Poster E1012b presentado en el 27th International Meeting on Organic Geochemistry September 13–18, 2015, Prague, Czech Republic, Amazonian ecosystems are considered important sinks for atmospheric CO2 on Earth. It is therefore desirable to preserve their biodiversity and productivity. In this communication an assessment of the influence of different agro-forestry practices on soil C storage in representative ecosystems from the Peruvian Ucayali region is approached by analyzing the soil lipid fraction. In fact, this organic matter fraction is an important source of analytical surrogates of soil C stabilization and accumulation processes (Naafs at al., 2004; Poulenard et al., 2004; Rumpel et al., 2004). Top (0–20 cm) and subsoil (20–40 cm) samples were taken from the Amazonian Ucayali region (Pucallpa, Perú), ranging from recent alluvial soils in muddy zones of riverside areas (wetlands referred to as ‘mud’, ‘beach’ and low ‘restinga’ soils) to more developed soils located in medium and higher riverine terraces, as well as in hills. The lipid fraction was Soxhlet extracted with a mixture of ichloromethane:methanol (2:1 by vol.), saponified and divided into neutral and acid subfractions. The acid fractions were then sequentially methylated and silylated prior to the chromatographic analysis (González-Vila et al., 2003). Neutral and acid sub-fractions were separated and the major compounds were identified by gas chromatography-mass spectrometry using an HP G1800A GCD System (electron impact detector at 70 eV) equipped with a DB-5 fused silica capillary column (30 m × 0.32 mm i.d., film thickness 0.25 µm) and using He as carrier gas at a flow rate of 1.5 mL min-1. The chromatographic oven temperature was programmed to increase from 40 to 100 ºC at 30 ºC min-1 and then to 300 ºC at 6 ºC min -1. The values of soil organic matter and lipids ranged from 25.8 to 5.8 g kg-1, and from 5.2 to 0.2 g kg-1, respectively. This variability as well as the differences in lipid molecular composition could suggest differences in the soils’ use and management practices (Van Bergen et al.,1996). The main families of signature lipids detected in the soil extracts were n-alkanes, linear isoprenoids, cyclic alkanes, n-fatty acids, branched fatty acids, unsaturated fatty acids, hydroxyacids, n-alcohols, ketones, polycyclic hydrocarbons and sterols. Very significant differences in qualitative and quantitative lipid composition were found in terms of soil depth. This effect was more pronounced in the soils from the riverine high terraces devoted to agro-forestry practices (Figs. 1 and 2). In addition, lipidic compounds of high molecular weight (i.e., di- and triterpenes) were detected as regular components of the free lipid fractions from the different ecosystems (wetlands, terraces and hills) reflecting specific vegetation and soil-use influences. Xenobiotic compounds (naphthenic acids) detected within the unresolved chromatographic ‘hump’ (highly unresolved mixture of cyclic or branched hydrocarbons) were also observed, indicating anthropogenic contamination by mineral oils. Likewise, dialkyl phthalates (Phth) from plasticizers were also detected., Projects CGL2012-38655-C04-01 and CGL2008-04296 and fellowship BES-2013-062573 given to N.T.J.M by the Spanish Ministry of Economy and Competitiveness. Dr. J.M.R. is the recipient of a fellowship from the JAE-Doc subprogram financed by the CSIC and the European Social Fund.

15 páginas.-- 6 figuras.-- 5 tablas.-- 39 referencias., This study addressed fire-induced changes in topsoil organic matter (SOM) from a eucalypt plantation in Portugal over 2 years by using three complementary biogeochemical techniques: elemental analysis, analysis of biomarkers from the total extractable lipids (TLE) and solid state 13C nuclear magnetic resonance (NMR) spectroscopy. Direct wildfire effects included a marked decrease in soil total organic carbon (TOC) and total nitrogen (TN) content. However, both contents seem to have recovered during the 2 years. Fire also substantially reduced the TLE, producing noticeable changes in its composition. These included the thermal breakdown and cracking of n-alkyl compounds. Ratios of short-to-long n-alkanes and n-fatty acid methyl esters (FAMEs) increased and typical carbon number predominance indices for n-alkanes (odd-to-even) and n-FAMEs (even-to-odd) were altered. Furthermore, the relative abundances of certain markers that are plant-species specific were modified, especially by decreasing terpenoids such as epiglobulol, ledol and globulol, which are characteristic of Eucalyptus globulus. Other differences observed in the burnt soil were the appearance of levoglucosan, a typical marker for the thermal alteration of polysaccharides, larger relative abundances of lignin-derived compounds (vanillin and methoxyphenols) and the presence of N-heteroaromatic structures, which suggested the accumulation of ‘black nitrogen’. The 13C NMR spectra indicated that the wildfire produced a considerable increase in the aromaticity and aromatic condensation of the topsoil SOM. This was reflected in a broadening of the signal of aromatic compounds at the expense of O-alkyl and alkyl-C compounds. The continuation of these differences in SOM quality during the 2-year study suggested a slow recovery of soil properties, possibly influenced by a limited recovery of the vegetation after the fire combined with the fire-enhanced losses of soil., The Foundation for Science and Technology (FCT) of Portugal, with co-funding by FEDER through the POCI2010 Programme, in the framework of the FIRECNUTS project (PTDC/AGR-CFL/104559/2008), as well as the research grants of S.R. Faria (SFRH/BD/75562/2010). The programme "Natural molecular structures as drivers and tracers of terrestrial C fluxes" (MOLTER) provided financial support to S.R Faria for the development of the laboratory experiments at IRNAS-CSIC (grant 3959). J.M. De la Rosa was the recipient of a fellowship from the CSIC JAE-Doc program co-financed by the European Social Fund (JAE-DOC-056). This work has been also partly funded by MINECO through project GEOFIRE (ref. CGL2012-268 38655-C04-01). We also want to acknowledge Valdemar Esteves for help with the use of the total organic carbon analyser (Shimadzu-TOC-5050A), Oscar Gonzalez-Pelayo for help with the description of the soil profiles and our FIRECNUTS colleagues for help with the sample collection and handling.

2 páginas.-- 1 figura.-- 4 referencias.-- Comunicación oral presentada en el VII Simposio Nacional sobre el control de la degradación y restauración de suelos (CONDEGRES 2015) 23-26 de junio, Bilbao, pág. 68-69, (2015), Se estudia el efecto de un incendio forestal en la firma isotópica (δ 13 C y δD) de series de n-alcanos liberadas por pirólisisis analítica directa (Py-CSIA) de fracciones granulométricas de suelos. Se encuentran marcadores isotópicos relacionados con el efecto del fuego en la materia orgánica del suelo (MOS) y se discute su utilidad para evaluar los efectos de los incendios forestales en los suelos y el seguimiento posterior de su recuperación, Trabajo parcialmente financiado por el Proyecto GEOFIRE (CGL2012-38655-C04-01). J.M. de la Rosa está contratado en el programa JAE-Doc CSIC/ESF (JAE-DOC 056) y N.T Jiménez-Morillo es becario FPI (BES-2013-062573).

I Seminar of the Forest Fires - Soils Network and I Ibero-Afro-American Symposium of Risks “Risks, Forest Fires and Territory” Faro, 4th, 5th and 6th of November of 2014.-- Panel 1: Forest Fires and Effects on Soils, Forest fires are a frequent phenomenon in Mediterranean ecosystems leading to the alteration of soil physical and chemical properties. In particular are well documented the fire induced changes in the composition and properties of soil organic matter (SOM). In addition, post fire soil erosion is usually a dramatic consequence of the above transformations, demanding the implementation of urgent restoration strategies, which needs to be scheduled and monitored. Taking the above considerations in mind, in this communication we report data on the alteration of fire affected soil properties along a time gradient. In August 2012, a wildfire affected a pine forest area (90 ha) in Montellano (Seville, SW Spain; longitude 37.00 º, latitude -5.56 º). Soil types in this area are Rendzic Leptosols and Calcaric Haplic Regosols. Soil samples were collected 1 month and 25 months after the wildfire. Control samples (unaffected by fire) were collected in an adjacent area. Branches, stems, bushes and plant residues on the fire-affected area were removed 16 months after the fire using heavy machinery as part of the post-fire management. Soil samples were analysed by elemental analysis (C, N and OC), 13C NMR spectroscopy and analytical pyrolysis (Py-GC/MS). The results obtained showed that in the burnt soils taken 2 years after the fire, the total organic carbon (TOC) content decreased drastically compared with the pre-fire status. Similarly, the water holding capacity (WHC) of the burnt soils were reduced, which is probably due to their loss of OC. Heating increased soil pH. Two years after fire this increase of the soil pH was transferred to deeper soil horizons ( ≥10 cm), which is probably related with the leaching of ashes. Concerning the analytical pyrolysis results, pyrochromatograms of the burnt soils taken two years after the fire were relatively enriched in aromatic compounds, whereas fatty acids and other lipids were reduced. The 13C NMR spectroscopy confirmed the increase in the aromaticity of the burnt SOM. It is assumed that these alterations on the SOM composition are contributing to an enhancement of the risk of soil erosion. Therefore in addition to the alteration of soil properties, it is expected an intensification of soil losses due to erosion. It is currently scheduled the monitoring of erosion risk in the fire affected area during the next years.

Poster presentado en lal EGU General Assembly 2015, held 12-17 April, 2015 in Vienna, Austria. id.2248, Wildfires may cause significant changes in soil physical and chemical properties. In addition, soil organic matter (SOM) content and chemical properties are usually affected by fire. Fire impacts may negatively affect soil health and quality, and induce or enhance runoff generation and, thereby, soil erosion risk and cause damages to the habitat of species. This fact is especially dramatic in Mediterranean ecosystems, where forest fires are a frequent phenomenon and restoration strategies are a key issue. The goals of this study are to determine: i) the immediate effects of fire on soil properties, including changes occurred in the quantity and quality of SOM and ii) the effect of post-fire actions on soil properties. In August 2012, a wildfire affected a forest area of approx. 90 ha in Montellano (Seville, SW Spain; longitude 37.00 º, latitude -5.56 º). This area is dominated by pines (Pinus pinaster and Pinus halepensis), and eucalypts (Eucaliptus globulus) with a Mediterranean climate. Dominant soil types are Rendzic Leptosols and Calcaric Haplic Regosols. It is a poorly limestone-developed soil (usually swallower than 25 cm). Four soil subsamples were collected 1 month and 25 months after fire within an area of approximately 200 m2. Subsamples were mixed together, homogenized, air-dried, crushed and sieved (2 mm). One control sample was collected in an adjacent area. The litter layer was removed by hand and studied separately. Branches, stems, bushes and plant residues on the fire-affected area were removed 16 months after the fire using heavy machinery as part of the post-fire management. The present research focuses on the study of the elemental composition (C, H and N) and physical properties (pH, water holding capacity, electrical conductivity) of bulk soil samples, and on the spectroscopic analysis (FT-IR, 13C NMR) and analytical pyrolysis data obtained from bulk the oils and from the humic acid fraction. immediate effects of fire, including the charring of vegetation and litter, as the input of charred residues may contribute to increase the total amount of soil organic matter. The post-fire removal of vegetation probably contributed to an additional loss of soil material due to an increase of the erosion risk. In addition, preliminary results point out that the burnt soil is not being recovered to the pre-fire conditions at a molecular level neither in the elemental composition. Results of this study will constitute a valuable tool for stake holders and decision makers to avoid additional alterations caused by post fire management of fire affected forests.

Comunicación oral presentada en EGU General Assembly 2015, held 12-17 April, 2015 in Vienna, Austria. id.1480, The application of biochar to soil is being proposed as a novel approach to establish a significant long-term sink for atmospheric carbon dioxide in terrestrial ecosystems. In addition, biochars offer a simple, sustainable tool for managing organic wastes and to produce added value products. Numerous research studies pointed out that biochar can act as a soil conditioner enhancing plant growth by supplying and, more importantly, retaining nutrients and by providing other services such as improving soil physical and biological properties.However, the effectiveness of biochar in enhancing plant fertility is a function of soil type, climate, and type of crop [2] but also of the biochar properties. The inherent variability of biochars due to different feedstock and production conditions implies a high variability of their effect on soil properties and productivity. Furthermore, due to the irreversibility of biochar application, it is necessary to perform detailed studies to achieve a high level of certainty that adding biochar to agricultural soils, for whatever reason, will not negatively affect soil health and productivity, The Marie Skłodowska-Curie actions (REA grant agreement nº PCIG12-GA-2012-333784-Biocharisma project) and the Spanish Ministry of Economy and Competitiveness (MINECO) (project PCGL2012-37041) are thanked for the financial support of the present study. The “Fondo Social Europeo” is thanked for funding J.M de la Rosa JAE-Doc contract. The European Biochar Network (Biochar as option for sustainable resource management-COST action TD1107) and Bodegas Torres (Spain) are acknowledged for providing the biochar samples

The structure of pyrogenic organic matter (PyOM) is still a matter of controversial discussions. In order to obtain more detailed information 2-dimenstional (2D) 13C HETeronucleus CORelation (HETCOR) Nuclear Magnetic Resonance (NMR) spectroscopy was applied to model compounds, fire-affected and unaffected soils. Here, the C-signal intensity is modulated by the proton chemical shift via scalar coupling, which allows a more detailed correlation of protons to carbon groups. With those first experiments, we demonstrated the high potential of this technique for the study of complex organic samples. Our results supported the concept of PyOM being a heterogeneous mixture of partly thermally altered molecules, rather than a highly condensed polyaromatic network. For the first time, a 2D 15N HETCOR NMR spectrum of PyOM was acquired, evidencing that Black Nitrogen is indeed an integral part of the Black Carbon network and that some amide N groups can survive intense charring., The Ministry of Economy and Competitiveness of Spain together with the European Regional Development Fund (FEDER) are acknowledged for funding the project CGL2012-37041. Marta Velasco-Molina acknowledges the International Humic Substance Society for granting a training award. The JAE-Doc program co-financed by the European Social Fund (JAE-DOC-056) is thanked for support of J.M. de la Rosa. The “CITIUS” research center of the University of Seville (Spain) together with Bruker Española S.A. is thanked for granting an award allowing the performance of the time consuming 2D-NMR spectra.

Wildfire may cause significant changes to soil organic carbon (SOM) on the forest floor and in the topsoil. This may have important implications for the export of particulate organic carbon from recently burnt forest areas. especially considering the often-observed increases in runoff and erosion following fire and leaching from the ash/soil. Carbon losses by post-fire runoff. however. have been poorly studied in Mediterranean regions. This research gap is being addressed by the FIRECNUTS project (PTDC/AGR-CFL/ 104559/2008). The study area is located in north-central Portugal. It was burnt by a wildfire in the summer of 2010. affecting some 250 ha of forest plantations of Maritime Pine (Pinus pinaster) and especially eucalypt (Eucalyptus globulus). This work focuses on characterization of sediments exports by overland flow of eucalypt plantations -one of the prevailing ando at the same time. most fire-prone forest types in north-central Portugal -that were collected at 4 occasions with roughly 6-monthly intervals, starting immediately after a wildfire in August 2010. The sediments were analyzed by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) in order to discern the molecular composition of the OM of sediment exports caused by post-fire runoff. Py-GC/ MS chromatogram showed in all the sediments. the presence of aromatic compounds mainly composed by benzenes and naphthalenes. typically found in burnt OM. In addition. methoxyphenols. derived from lignin and n-alkanes/ enes pairs were identified. Preliminary results suggest that wildfire caused j) the degradation and transport of the most labile structures and ii) formation of newly thermally-altered OM.

Soil water repellency (WR) is normally induced by organic substances covering the surface of mineral particles and aggregates or that are present in interstitial spaces within the soil matrix. Despite the relevance of this phenomenon for soil functioning, there is little information about nature and molecular structure of organics related with WR. Soil samples were collected under selected species growing in a sandy soil from the Doñana National Park (SW Spain), Coak oak (Quercus suber, QS), Eagle fern (Pteridium aquilinum, PA), Pinus (Pinus pinea, PP) and Rockrose (Halimium halimifolium, HH). Soil WR and physical chemical characteristics including SOM content were assessed in fine earth soil samples (PA>PP>HH. A positive correlation was observed between WR from each sieve size fraction and soil organic matter (SOM) content. Despite the ¿a priori¿ low complexity of the soils studied, more than 200 organic compounds were released after a direct analytical pyrolysis (Py-GC/MS at 500 ºC) of soil samples and size fractions. The relation between organics in the pyrolysates and soil WR is studied using chemometric analysis that include principal component analysis (PCA) of pyrolysis compounds and groupings according to chemical family and potential biotic precursors (unspecific aromatic compounds, alkane/alkene pairs, fatty acids, lignin derived, polysaccharide derived, protein/polypeptide derived and steranes)., European Regional Development Fund and the European Bioenergy Research Institute .-- Interreg and BioenNW.-- SUPERGEN Bioenergy Hub .-- Aston University.-- Gerstel.-- CDS Analytical.-- SHIMADZU.-- Frontier Lab.-- Gas Data.-- PyroLab.-- SciMed.-- Elsevier