Antonio José Fernández Espinosa | Universidad de Sevilla (original) (raw)

Papers by Antonio José Fernández Espinosa

Analytical and Bioanalytical Chemistry, 2004

Eighty-three samples of atmospheric particles were collected at a representative traffic site in ... more Eighty-three samples of atmospheric particles were collected at a representative traffic site in the Mediterranean city of Seville during a period of one year. Urban particles were collected on quartz filters with a high-volume sampler coupled with a cascade impactor which separates particles into six size ranges: >10, 10–4.9, 4.9–2.7, 2.7–1.3, 1.3–0.6, and <0.6 μm. The total metal content, its distribution by size (physical speciation), and the concentrations of different chemical forms (chemical speciation) in particles less than 0.6 μm were determined. The chemical speciation scheme furnished four fractions: soluble and exchangeable metals; carbonates, oxides, and reducible metals; oxidisable and sulfidic metals bound to organic matter; and residual metals. The samples were analysed by ICP–OES for Pb, Ni, Cd, S, Fe, Zn, Cu, Ba, Mn, and V. Gaseous pollutants, traffic intensities, and primary meteorological data provided by the atmospheric and traffic networks were statistically related to the analytical data. Analytical and statistical results from physical and chemical speciation singled out Ba as a valid tracer of vehicular traffic, instead of Pb, in cities with high traffic density. Another important relationship was found between Pb and Cu. Physical speciation of lead showed that the major risk for health was from fine particles less than 2.7 μm, because particles between 2.7 and 0.6 μm were the size fractions of the total suspended particles with the major mass abundance of lead (mainly particles between 2.7 and 1.3 μm) and because particles less than 0.6 μm were the fraction of airborne particles most abundant in the urban air. Chemical speciation results showed that special attention must be taken with Ni and Cd concentrations, because of their high potential bioavailability, mainly a result of the high solubility of the chemical forms of Ni in the finest particles.

Analytical and Bioanalytical Chemistry, 2005

The size distribution of polycyclic aromatic hydrocarbons (PAH) was determined for airborne parti... more The size distribution of polycyclic aromatic hydrocarbons (PAH) was determined for airborne particles from a large city with high vehicular traffic. The analytical method was optimised and validated using NIST standard reference material (SRM 1649a Urban Dust). The 16 priority PAH listed in the US-EPA were Soxhlet-extracted from filtered particulate matter and then fractionated using on-column chromatography. The aromatic fraction was quantified by gas chromatography-mass spectrometry. Real samples of particles collected in Seville (Spain) were analysed using the validated method. Values for the total concentration of PAH in the air, as well as the concentrations of each PAH in six particle-size ranges were obtained. Values of the PAH in TSP, PM10, PM2.5 and PM1 were assessed.

Analytical and Bioanalytical Chemistry, 2011

In this study a new method of principal component (PC) analysis, sequential PC analysis (SPCA), i... more In this study a new method of principal component (PC) analysis, sequential PC analysis (SPCA), is proposed and assessed on real samples. The aim was to identify the atmospheric emission sources of soluble compounds in rainwater samples, and the sample collection was performed with an automatic sampler. Anions and cations were separated and quantified by ion chromatography, whereas trace metals and metalloids were determined by inductively coupled plasma mass spectrometry. SPCA results showed eight interfering PCs and ten significant PCs. The interfering cases originated from different atmospheric sources, such as resuspended crustal particles, marine aerosols, urban traffic and a fertilizer factory. The significant PCs explained 84.6% of the total variance; 28.1% accounted for the main contribution, which was resuspended industrial soil from a fertilizer factory containing NO 2-, NH 4+, NO 3-, SO 42-, F-, Al, K+, Mn, Sb and Ca2+ as indicators of the fertilizer factory. Another important source (15.0%) was found for Na+, Mg2+, K+, Cl- and SO 42-, which represents the marine influence from south and southwest directions. Emissions of Ba2+, Pb, Sr2+, Sb and Mo, which represent a traffic source deposited in soils, were identified as another abundant contribution (12.1%) to the rainwater composition. Other important contributions to the rainwater samples that were identified through SPCA included the following: different urban emissions (Cu, As, Cd, Zn, Mo and Co, 18.1%), emissions from vegetation (HCOO-, 7.7%) and emissions from industrial combustion processes (Ni, V 15.6%). The application of SPCA proved to be a useful tool to identify the complete information on rainwater samples as indicators of urban air pollution in a city influenced mainly by vehicle traffic emissions and resuspended polluted soils.

Atmospheric Environment, 2004

A series of 41 samples of atmospheric particles below 0.61 μm were collected at 12 sites in a Med... more A series of 41 samples of atmospheric particles below 0.61 μm were collected at 12 sites in a Mediterranean city. Meteorological data were related to analytical data. Direct observation technique was used to support the results. Total content and chemical form concentrations for 11 metals were determined, the chemical forms being determined through a specific speciation scheme for fine particles. All sampling sites were differentiated according to the level of metallic pollution. These levels were 40% higher on weekdays than at weekends. Organic-sulphidic chemical form levels of Cd, Pb, Mn and Ti were highest on weekdays. Sources from the sampling sites were influenced by local emissions more than by transferred pollution. Various sources were identified by a sequential principal component analysis as the resuspended soil particles, oil combustion, emissions from foundries and traffic.

Atmospheric Environment, 2001

The size distribution of metals in aerosols has been studied in 12 areas of the city of Seville. ... more The size distribution of metals in aerosols has been studied in 12 areas of the city of Seville. Urban particles were collected with a high-volume sampling system equipped with a cascade impactor, which effectively separates the particulate matter into six-size ranges. Forty-one samples were collected in spring 1996. Each filter was extracted with a mixture of nitric and percloric acids. The acid solutions of the samples were analysed in six-particle fractions by inductively coupled plasma atomic emission spectrometry (ICP-AES). The impactor stage fractionation of particles shows a typical bimodal distributions, one corresponding to the fine mode below 1 μm (55%), and the other to the coarse mode around 10 μm (32%). With regard to the size distribution of metals, we concluded that potentially toxic metals, such as nickel, lead and cadmium are mainly accumulated in the smaller particles, with percentages of 72.6, 69.4 and 63.8%, respectively. Lead have a concentration of 63.7 ng m−3, more than copper and manganese (26.7 and 16.5 ng m−3) and above all more than nickel, cobalt and cadmium (1.97, 0.54 and 0.32 ng m−3).

Atmospheric Environment, 2002

The chemical speciation of 11 metals in aerosols has been studied in 12 areas of the city of Sevi... more The chemical speciation of 11 metals in aerosols has been studied in 12 areas of the city of Seville (Spain). Urban particles were collected with a high-volume sampling system equipped with a cascade impactor, which effectively separates the particulate matter into six size ranges. Forty-one samples were collected in the spring of 1996. The chemical speciation was studied in the finest particles of the impactor system (<0.61 μm), those that can penetrate into the alveolar region of the lung. This speciation scheme is specific for urban particles and consisted of four fractions: 1. soluble and exchangeable metals; 2. carbonates, oxides and reducible metals; 3. bound to organic matter, oxidisable and sulphidic metals; and 4. residual metals. The sample extractions were analysed for 11 metals by inductively coupled plasma atomic emission spectrometry (ICP-AES). The chemical speciation of metals showed that the metals with highest percentages in the different fractions are vanadium (50.4%) in the soluble and exchangeable fraction, calcium (39.7%) in the carbonates, oxides and reducible fraction, magnesium (59.2%) in the bound to organic matter, oxidisable and sulphidic fraction, and iron (54.6%) in the residual fraction. Correlations between all the variables have been studied and the results showed common sources to the metal fractions correlated in relation to the industrial activities and mainly the vehicular traffic.

$Research paper thumbnail of A three-step metal fractionation scheme for fly ashes collected in an Argentine thermal power plant$

Fuel, 2008

A new three-step fractionation scheme was applied to study the distribution of Al, As, Cd, Cr, Cu... more A new three-step fractionation scheme was applied to study the distribution of Al, As, Cd, Cr, Cu, Fe, Mn, Mo, Ni, Pb, S, Sb, Ti, V and Zn in fly ashes collected in the electrostatic precipitator of a thermal power plant in the city of San Nicolás (Argentina). Seven samples were collected during one week of operation in 2005. For the fractionation, the scheme applied consisted of extracting the elements in three fractions: (i) soluble and exchangeable elements, (ii) carbonates, oxides and reducible elements and (iii) residual elements. Metals and metalloids at μg g−1 level were determined in each fraction by plasma based techniques namely, inductively coupled plasma optical emission spectrometry (ICP OES) and inductively coupled plasma mass spectrometry (ICP-MS). For validation, a certified reference materials NIST SRM 2711 (Montana soil) was subject to the same chemical sequential extraction procedure. X-ray diffraction powder (XRD) analysis and scanning electron microscopy (SEM) were used to characterize the major minerals present in the matrix. The predominant phases found in the total samples were mullite, quartz, iron oxides and lime. Total analyte concentration varied (in μg g−1) from 1.54 for Cd to 30 600 for Al. The leachability of the 15 elements under study proved to be different. All the elements (except Cd and Pb) were detected in the soluble fraction in the order: Cu (0.10%) ∼ Mn (0.13%) < Ni (0.17%) ∼ Ti (0.19%) ∼ Fe (0.20%) ∼ As (0.21%) < Zn (0.86%) < Al (1.3%) < Cr (2.9%) < V (3.9%) < Sb (6.9%) < Mo (45.1%) < S (58.0%). Percentages higher than 20% of S (24.1%) < V (27.5%) < Mn (29.0%) were detected in the second fraction. Al, As, Cr, Cd, Cu, Fe, Ni, Pb, Sb and Zn were mostly associated to the residual fraction. Recoveries of the overall procedure varied between 106% (Mo) and 72% (Cr).