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Abstract: Madrid, the largest city of Spain, has some and unique air pollution problems, such as emissions from residential coal burning, a huge vehicle fleet and frequent African dust outbreaks, along with the lack of industrial emissions. The chemical composition of particulate matter (PM) was studied during summer and winter sampling campaigns, conducted in order to obtain size-segregated information at two different urban sites (roadside and urban background). PM was sampled with high volume cascade impactors, with 4 stages: 10–2.5, 2.5–1, 1–0.5 and <0.5μm. Samples were solvent extracted and organic compounds were identified and quantified by GC-MS. Alkanes, polycyclic aromatic hydrocarbons (PAHs), alcohols and fatty acids were chromatographically resolved. The PM1–2.5 was the fraction with the highest mass percentage of organics. Acids were the organic compounds that dominated all particle size fractions. Different organic compounds presented apparently different seasonal characteristics, reflecting distinct emission sources, such as vehicle exhausts and biogenic sources. The benzo[a]pyrene equivalent concentrations were lower than 1ngm−3. The estimated carcinogenic risk is low. [Copyright &y& Elsevier]

This work describes the first analytical method specifically developed for the multianalyte determination of several drugs of abuse and their metabolites in air. The methodology is based on pressurized liquid extraction (PLE) of atmospheric particles collected by means of high volume sampler equipped with quartz microfiber filters and subsequent analysis of the extracts by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Up to 17 different compounds belonging to five different chemical classes (cocainics, amphetamine-like compounds, opioids, cannabinoids, and lysergic compounds) are determined by means of this methodology. Acquisition is performed in the selected reaction monitoring (SRM) mode recording two transitions per compound (except for amphetamine). Quantitation by the internal standard method is based on the use of surrogated deuterated standards. The method has been validated in terms of linearity, accuracy, repeatability and sensitivity with satisfactory results. Absolute recoveries were above 50% for most investigated compounds. Method precision showed relative standard deviations (RSD) below 13% for all compounds, except for cannabinoids. The method limits of determination ranged from 0.35 pg/m(3) (for 2-oxo-3-hydroxy-LSD) to 22.55 pg/m(3) (for 11-nor-9 carboxy THC). Finally, as a part of the method validation, the optimized procedure was applied to the analysis of ambient air samples (fine grain-size particulates, PM(2.5)) collected at two urban background sites in Barcelona and Madrid (Spain). Results evidenced the presence of cocaine, benzoilecgonine, tetrahydrocannabinol, ecstasy, amphetamine, methamphetamine, and heroin in some or all of the samples investigated. The highest mean daily levels corresponded to cocaine (850 pg/m(3)) followed by heroin (143 pg/m(3)).

Source apportionment study was performed, applying principal component analysis to the results of 221 chemical analyses of PM10 and PM2.5 samples collected daily from the industrial (but low traffic) Spanish town of Puertollano over a 14-month period during 2004-2005. Results reveal compositional variations attributable to different mixtures of natural and anthropogenic materials, mainly soil and rock dust (crustal), marine salt (only in PM10), petrochemical refinery emissions, and particles attributed to the combustion of local coal, which is unusually rich in Pb and Sb. During the study period there were 34 pollution episodes when PM10 exceeded 50 tg m(-3), mostly due to winter air temperature inversions, regional atmospheric stagnation, or African dust incursions (North African, NAF days: usually in summer). Whereas the crustal component during NAF episodes averaged 52% with a PM2.5/PM10 ratio of 0.54, this dropped to 29% and a PM2.5/PM10 of 0.67 during non-NAF days when anthropogenic materials predominated. Abnormally enhanced concentrations of pathfinder metallic trace elements provide additional evidence for source apportionment: thus aerosols with raised levels of Pb and Sb are associated with local coal combustion, Ni and V can be linked to petrochemical PM emissions, and Ti, Mn, Rb, and Ce are particularly characteristic of crustal dust incursions.