title: Composition and spectra of copper-carotenoid sediments from a pyrite mine stream in Spain.
abstract: Mine drainages of La Poderosa (El Campillo, Huelva, Spain), located in the Rio Tinto Basin (Iberian Pyrite Belt) generate carotenoid complexes mixed with copper sulfates presenting good natural models for the production of carotenoids from microorganisms. The environmental conditions of Rio Tinto Basin include important environmental stresses to force the microorganisms to accumulate carotenoids. Here we show as carotenoid compounds in sediments can be analyzed directly in the solid state by Raman and Luminescence spectroscopy techniques to identify solid carotenoid, avoiding dissolution and pre-concentration treatments, since the hydrous copper-salted paragenesis do not mask the Raman emission of carotenoids. Raman spectra recorded from one of these specimens' exhibit major features at approximately 1006, 1154, and 1520 cm(-1). The bands at 1520 cm(-1) and 1154 cm(-1) can be assigned to in-phase C=C (γ(-1)) and C-C stretching (γ(-2)) vibrations of the polyene chain in carotenoids. The in-plane rocking deformations of CH3 groups linked to this chain coupled with C-C bonds are observed in the 1006 cm(-1) region. X-irradiation pretreatments enhance the cathodoluminescence spectra emission of carotenoids enough to distinguish organic compounds including hydroxyl and carboxyl groups. Carotenoids in copper-sulfates could be used as biomarkers and useful proxies for understanding remote mineral formations as well as for terrestrial environmental investigations related to mine drainage contamination including biological activity and photo-oxidation processes.
authors: Museo Nacional de Ciencias Naturales (MNCN-CSIC), Calle José Gutiérrez Abascal 2, 28006 Madrid, Spain. Electronic address: guinea@mncn.csic.es.
authors: Javier
authors: J
authors: Garcia-Guinea
authors: Museo Nacional de Ciencias Naturales (MNCN-CSIC), Calle José Gutiérrez Abascal 2, 28006 Madrid, Spain. Electronic address: mfurio@mncn.csic.es.
authors: Marta
authors: M
authors: Furio
authors: Museo Nacional de Ciencias Naturales (MNCN-CSIC), Calle José Gutiérrez Abascal 2, 28006 Madrid, Spain. Electronic address: ssmilk@mncn.csic.es.
authors: Sergio
authors: S
authors: Sanchez-Moral
authors: Instituto de Recursos Naturales y Agrobiología (IRNAS-CSIC), Avenida Reina Mercedes 10, 41012 Sevilla, Spain. Electronic address: vjurado@irnase.csic.es.
authors: Valme
authors: V
authors: Jurado
authors: Dpto. Dosimetría de Radiaciones, CIEMAT, Avenida Complutense 22, 28040 Madrid, Spain. Electronic address: v.correcher@ciemat.es.
authors: Virgilio
authors: V
authors: Correcher
authors: Instituto de Recursos Naturales y Agrobiología (IRNAS-CSIC), Avenida Reina Mercedes 10, 41012 Sevilla, Spain. Electronic address: saiz@irnase.csic.es.
authors: Cesareo
authors: C
authors: Saiz-Jimenez
mesh_terms: D002338:Carotenoids / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D004055:Differential Thermal Analysis; D004566:Electrodes; D019015:Geologic Sediments / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D049449:Luminescence; D008855:Microscopy, Electron, Scanning; D008906:Mining; D045483:Rivers / Q000737:chemistry*; D013030:Spain; D013052:Spectrometry, X-Ray Emission; D013059:Spectrum Analysis, Raman; D013440:Sulfides / Q000737:chemistry*; D013818:Thermogravimetry; D014961:X-Ray Diffraction
chemical_list: D013440:Sulfides; C011342:pyrite; D002338:Carotenoids; D003300:Copper; D007501:Iron
keywords: Biomarker; Carotenoids; Cathodoluminescence; Copper-sulfates; Raman; Riotinto