Sensitivity of PM oxidative potential to aerosol chemical composition at a Mediterranean urban site: ascorbic acid versus dithiothreitol measurements.

Unlabelled: The oxidative potential (OP) of PM daily samples collected at a traffic site in southeastern Spain during summer and winter was assessed by two acellular assays: the ascorbic acid (AA) and dithiothreitol (DTT) methods. Although PM levels were similar during both periods, OP values (expressed in nmol min m) showed a defined seasonal trend. The AA activity was higher in summer than in winter, whereas the DTT reactivity exhibited an opposite seasonal pattern.

Regional and long-range transport of aerosols at Mt. Aitana, Southeastern Spain.

More than 150 particulate matter (PM) samples with aerodynamic diameters smaller than 1 and 10μm (PM and PM, respectively) were collected during an 18-month sampling campaign at Mt. Aitana (1558m a.s.

Characterization of hydrocarbons in aerosols at a Mediterranean city with a high density of palm groves.

Samples of PM1 and PM10 were collected for 1 year at an urban background station in the city of Elche (southeastern Spain) and analyzed to determine the content of n-alkanes and polycyclic aromatic hydrocarbons (PAHs). A few samples were also gathered at a second sampling point established at one of the several palm tree gardens of the city in order to evaluate the influence of biogenic emissions on the urban levels of n-alkanes. Diagnostic parameters obtained for aliphatic hydrocarbons (carbon maximum number (C max), carbon preference index (CPI), and wax n-alkane content (%WNA)) revealed a higher contribution of biogenic n-alkanes in PM10 than in PM1.

BTX in urban areas of eastern Spain: a focus on time variations and sources.

Seasonal and daily cycles of BTX were studied in a non-industrialized city (Alicante) and an urban area near an oil refinery plant (Castellón) in order to evaluate the influence of different sources on time variations. Lower levels were observed in summer than in winter at both locations due to higher dispersion conditions and photochemical removal of BTX during the summer season. Daily patterns showed seasonal differences and were controlled by traffic emissions and the evolution of the mixing layer height, with no influence of the petroleum refinery plant in the city of Castellón.

Particle-bound polycyclic aromatic hydrocarbons in an urban, industrial and rural area in the western Mediterranean.

Particle-bound PAHs were measured at three sites in southeastern Spain (an urban background location, a suburban-industrial site in the vicinity of two cement plants and a rural area) in order to investigate the influence of the type of location on PAH concentrations. A clear influence of cement production on particulate PAH levels could not be established since for the urban background and suburban-industrial sites the average concentrations of total PAHs in the PM2.5 fraction were very similar (1.

Application of an automatic thermal desorption-gas chromatography-mass spectrometry system for the analysis of polycyclic aromatic hydrocarbons in airborne particulate matter.

The application of the thermal desorption (TD) method coupled with gas chromatography-mass spectrometry (GC-MS) to the analysis of aerosol organics has been the focus of many studies in recent years. This technique overcomes the main drawbacks of the solvent extraction approach such as the use of large amounts of toxic organic solvents and long and laborious extraction processes. In this work, the application of an automatic TD-GC-MS instrument for the determination of particle-bound polycyclic aromatic hydrocarbons (PAHs) is evaluated.

Di-2-pyridylmethylamine-based palladium complexes as new catalysts for Heck, Suzuki, and Sonogashira reactions in organic and aqueous solvents.

A new palladium-dipyridylmethylamine complex is an excellent catalyst for C-C bond-forming processes such as the Heck, Suzuki, and Sonogashira reactions in organic and aqueous solvents under homogeneous conditions. [reaction: see text]