title: Fertilizer characterization: isotopic data (N, S, O, C, and Sr).
abstract: A detailed isotopic characterization (delta15N(Ntotal), delta15N(NO3), delta18O(NO3), delta34S(SO4), delta18O(SO4), (delta13C(Ctotal), and 87Sr/86Sr) of 27 commercial fertilizers used in Spain is presented in this paper. Results together with a compilation of fertilizer isotopic published data are used for two purposes: (i) to identify the origin of the primary constituents and raw materials used in fertilizer manufacture and relate these data with their heavy metals and rare earth elements (REE) contents; (ii) to compare the fertilizer isotopic signatures with natural values and other anthropogenic pollutants and evaluate the usefulness of multi-isotopic analyses to trace fertilizer contaminations in future study cases. Isotope data permit us to know, in most cases, the origin of the primary constituents of fertilizers, and the 87Sr/86Sr ratio distinguishes the origin of the phosphate content--phosphorites or carbonatites--which in turn implies a qualitatively defined and potentially contaminant presence of REE and heavy metals in fertilizers. Delta15N, delta34S, and 87Sr/86Sr have already been used to trace fertilizer contaminations. Their utility can be improved by the coupled use of delta15N(NO3)-delta18O(NO3) and delta34S(SO4)-delta18O(SO4) to evaluate the fractionation processes that can affect contaminants. Moreover, multi-isotopic analyses, using heavy isotopes, allow us to see beyond the fractionation effects to the fertilizer stable isotope signatures and a better distinction from other anthropogenic contaminants.
authors.affiliation: Department de Cristal.lographia, Mineralogia i Dipòsits Minerals, Facultat de Geologia, Universitat de Barcelona, Martí i Franquès, s/n 08028, Barcelona, Spain. lvitoria@geo.ub.es
authors.forename: Laura
authors.initials: L
authors.lastname: Vitòria
authors.forename: Neus
authors.initials: N
authors.lastname: Otero
authors.forename: Albert
authors.initials: A
authors.lastname: Soler
authors.forename: Angels
authors.initials: A
authors.lastname: Canals
mesh_terms: D004785:Environmental Pollutants / Q000032:analysis*; D005308:Fertilizers / Q000032:analysis*; D007554:Isotopes / Q000032:analysis; D019216:Metals, Heavy / Q000032:analysis; D008674:Metals, Rare Earth / Q000032:analysis; D012016:Reference Values; D013030:Spain
chemical_list: D004785:Environmental Pollutants; D005308:Fertilizers; D007554:Isotopes; D019216:Metals, Heavy; D008674:Metals, Rare Earth