title: Multivariate factorial analysis to design a robust batch leaching test to assess the volcanic ash geochemical hazard.
abstract: A method to obtain robust information on short term leaching behaviour of volcanic ashes has been developed independently on the sample age. A mixed factorial design (MFD) was employed as a multivariate strategy for the evaluation of the effects of selected control factors and their interactions (amount of sample (A), contact time (B), and liquid to solid ratio or L/S (C)) on the leaching process of selected metals (Na, K, Mg, Ca, Si, Al, V, Mn, Fe, and Co) and anions (Cl(-) and SO(4)(2-)). Box plots of the data acquired were used to evaluate the reproducibility achieved at different experimental conditions. Both the amount of sample (A) and leaching time (B) had a significant effect on the element stripping whereas the L/S ratio influenced only few elements. The lowest dispersion values have been observed when 1.0 g was leached with an L/S ratio equal to 10, shaking during 4 h. The entire method is completed within few hours, and it is simple, feasible and reliable in laboratory conditions.
authors.affiliation: Institute of Earth Sciences Jaume Almera, ICTJA-CSIC, Barcelona, Spain.
authors.forename: Flavia
authors.initials: F
authors.lastname: Ruggieri
authors.forename: Raúl A
authors.initials: RA
authors.lastname: Gil
authors.forename: Jose-Luis
authors.initials: JL
authors.lastname: Fernandez-Turiel
authors.forename: Julio
authors.initials: J
authors.lastname: Saavedra
authors.forename: Domingo
authors.initials: D
authors.lastname: Gimeno
authors.forename: Agustin
authors.initials: A
authors.lastname: Lobo
authors.forename: Luis D
authors.initials: LD
authors.lastname: Martinez
authors.forename: Alejandro
authors.initials: A
authors.lastname: Rodriguez-Gonzalez
mesh_terms: D000704:Analysis of Variance; D000838:Anions / Q000032:analysis; D005163:Factor Analysis, Statistical; D015386:Hazardous Substances / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D008670:Metals / Q000032:analysis; D010316:Particle Size; D016062:Porosity; D012044:Regression Analysis; D015203:Reproducibility of Results; D012995:Solubility; D018707:Volcanic Eruptions / Q000032:analysis*
chemical_list: D000838:Anions; D015386:Hazardous Substances; D008670:Metals