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Atmospheric particulate matter (PM) has been related to numerous adverse health effects in humans. Nowadays, it is believed that one of the possible mechanisms of toxicity could be the oxidative stress, which involves the development of reactive oxygen species (ROS). Different assays have been proposed to characterize oxidative stress, such as dithiothreitol (DTT) and ascorbic acid (AA) acellular assays (OPDTT and OPAA), as a metric more relevant than PM mass measurement for PM toxicity. This study evaluates the OP of the bioaccessible fraction of 65 PM10 samples collected at an Atlantic Coastal European urban site using DTT and AA assays. A physiologically based extraction (PBET) using Gamble's solution (GS) as a simulated lung fluid (SLF) was used for the assessment of the bioaccessible fraction of PM10. The use of the bioaccessible fraction, instead of the fraction assessed using conventional phosphate buffer and ultrasounds assisted extraction (UAE), was compared for OP assessment. Correlations between OPDTT and OPAA, as well as total and bioaccessible concentrations of polycyclic aromatic hydrocarbons (PAHs) and metal(oid)s, were investigated to explore the association between those compounds and OP. A correlation was found between both OP (OPDTT and OPAA) and total and bioaccessible concentrations of PAHs and several metal(oid)s such as As, Bi, Cd, Cu, Ni, and V. Additionally, OPDTT was found to be related to the level of K+. [ABSTRACT FROM AUTHOR]

Although restricting environmental quality values for organotin compounds (OTs) are set by Directive 2013/39/EU of the European Parliament, marine environment remains being affected due to maritime circulation at global scale. Fish and seafood accumulate OTs, making fish and seafood consumption the main source of OTs in humans. Because of the fish and seafood matrices complexity and the required low limits of detection, a robust and fast procedure for the quantification of OTs in fish and seafood, using ultrasound-assisted extraction and gas chromatography–tandem mass spectrometry, was validated and applied. Detection (2.7 µg Sn kg−1) and quantification (8.0 µg Sn kg−1) limits, repeatability and intermediate precision (<10%), accuracy by analysing ERM®-CE477 Mussel Tissue and analytical recoveries (65–122%) were assessed. Multivariate analysis shown that the matrix effect for some OTs displayed good negative correlation with the fat and protein content. Health risk assessment of OTs intake revealed no serious risk for human consumption. [ABSTRACT FROM AUTHOR]

This study investigates spatio-temporal variations of PM10 mass concentrations and associated metal(oid)s, δ13C carbon isotope ratios, polycyclic aromatic hydrocarbons (PAHs), total organic carbon (TOC) and equivalent black carbon (eBC) concentrations over a half year period (from March 2017 to October 2017) in two residential areas of Medellín (MED-1 and MED-2) and Itagüí municipality (ITA-1 and ITA-2) at a tropical narrow valley (Aburrá Valley, Colombia), where few data are available. A total of 104 samples were analysed by using validated analytical methodologies, providing valuable data for PM10 chemical characterisation. Metal(oid)s concentrations were measured by inductively coupled plasma mass spectrometry (ICP-MS) after acid digestion, and PAHs concentrations were measured by Gas Chromatography-Mass Spectrometry (GC–MS) after Pressurised Hot Water Extraction (PHWE) and Membrane Assisted Solvent Extraction (MASE). Mean PM10 mass concentration ranged from 37.0 µg m−3 to 45.7 µg m−3 in ITA-2 and MED-2 sites, respectively. Al, Ca, Mg and Na (from 6249 ng m−3 for Mg at MED-1 site to 10,506 ng m−3 for Ca at MED-2 site) were the major elements in PM10 samples, whilst As, Be, Bi, Co, Cs, Li, Ni, Sb, Se, Tl and V were found at trace levels (< 5.4 ng m−3). Benzo[g,h,i] perylene (BghiP), benzo[b + j]fluoranthene (BbjF) and indene(1,2,3-c,d)pyrene (IcdP) were the most profuse PAHs in PM10 samples, with average concentrations of 0.82–0.86, 0.60–0.78 and 0.47–0.58 ng m−3, respectively. Results observed in the four sampling sites showed a similar dispersion pattern of pollutants, with temporal fluctuations which seems to be associated to the meteorology of the valley. A PM source apportionment study were carried out by using the positive matrix factorization (PMF) model, pointing to re-suspended dust, combustion processes, quarry activity and secondary aerosols as PM10 sources in the study area. Among them, combustion was the major PM10 contribution (accounting from 32.1 to 32.9% in ITA-1 and ITA-2, respectively), followed by secondary aerosols (accounting for 13.2% and 23.3% ITA-1 and MED-1, respectively). Finally, a moderate carcinogenic risk was observed for PM10-bound PAHs exposure via inhalation, whereas significant carcinogenic risk was estimated for carcinogenic metal(oid)s exposure in the area during the sampling period. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs) in atmospheric particulate matter have adverse effects on human health, yet total PAH concentrations should overestimate the toxicity compared to the bioavailable amount of PAHs. To explore this hypothesis, we measured PAHs oral bioavailability in vitro in particulate matter with aerodynamic diameter lower than 10 µm (PM10) using a test that mimics the human digestive system. This assay combines the use of simulated gastrointestinal fluids and a dialysis membrane to simulate intestinal absorption. Results show that oral PAH bioavailability was below 5%, with fluorene, anthracene, acenaphthene and phenanthrene as the most bioavailable PAHs. Data suggest no carcinogenic risk of oral bioavailable PM10-bound PAHs following a health risk assessment via inhalation-ingestion by using benzo(a)pyrene-equivalent carcinogenic concentration and hazard indexes. To our best knowledge, this is the first research study of in vitro oral bioavailability estimation of PM10-associated PAHs. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs) were assessed in 65 atmospheric particulate matter (PM10) samples collected at a coastal urban area of Southwest Atlantic Europe during the 1-year period. Analytical methodology was successfully validated in terms of limits of detection and quantification, linearity, precision and trueness by using ERM CZ100 reference material and analytical recovery studies. Status of PM10-bound PAHs and their relationship with other PM10 constituents (major ions, trace metals, equivalent black carbon (eBC) and UV-absorbing particulate matter (UVPM)) in an area where few data are available is provided. Benzo(b)fluoranthene (BbF) and benzo(e)pyrene (BeP) were observed to be predominant in all samples analysed with average concentrations of 1.6 and 1.5 ng m−3, respectively. Furthermore, high RSDs were achieved for PAHs during the sampling period, which reflects inherent heterogeneity of the atmospheric particles besides weather conditions variations. Statistical significant seasonal changes in PAH concentrations during summer and winter seasons were not found. Data obtained from molecular PAH indices, univariate analysis, principal component analysis (PCA) and cluster analysis (CA) suggested a pyrogenic origin derived from the continuous harbour activity and marine and road traffic emissions at the studied urban site throughout the year. Additionally, major ion and metal(oid) concentrations in PM10 samples were also used as tracers of PAH origin and for PM10 source exploration. Linear and quadratic models have shown that the PAH concentrations exhibited correlation with some metals (Ba, Bi, Cu, Pb, Sb and Zn) and NO3− concentrations. Finally, carcinogenic and mutagenic potencies and inhalation cancer risk (ILCRinh) posed by PM10-bound PAHs were assessed. [ABSTRACT FROM AUTHOR]

Plastic litter dispersed in the different environmental compartments represents one of the most concerning problems associated with human activities. Specifically, plastic particles in the micro and nano size scale are ubiquitous and represent a threat to human health and the environment. In the last few decades, a huge amount of research has been devoted to evaluate several aspects of micro/nanoplastic contamination: origin and emissions, presence in different compartments, environmental fate, effects on human health and the environment, transfer in the food web and the role of associated chemicals and microorganisms. Nevertheless, despite the bulk of information produced, several knowledge gaps still exist. The objective of this paper is to highlight the most important of these knowledge gaps and to provide suggestions for the main research needs required to describe and understand the most controversial points to better orient the research efforts for the near future. Some of the major issues that need further efforts to improve our knowledge on the exposure, effects and risk of micro/nano-plastics are: harmonization of sampling procedures; development of more accurate, less expensive and less time-consuming analytical methods; assessment of degradation patterns and environmental fate of fragments; evaluating the capabilities for bioaccumulation and transfer to the food web; and evaluating the fate and the impact of chemicals and microorganisms associated with micro/nano-plastics. The major gaps in all sectors of our knowledge, from exposure to potentially harmful effects, refer to small size microplastics and, particularly, to the occurrence, fate and effects of nanoplastics. [ABSTRACT FROM AUTHOR]

Light-absorbing carbonaceous aerosols (including black carbon (BC)) pose serious health issues and play significant roles in atmospheric radiative properties. Two-year measurements (2015–2016) of aerosol light absorption, combined with measurements of sub-micrometric particles, were continuously conducted in A Coruña (northwest (NW) Spain) to determine their light absorption properties: absorption coefficients (σabs) and the absorption Ångström exponent (AAE). The mean and standard deviation of equivalent black carbon (eBC) during the period of study were 0.85 ± 0.83 µg m−3, which are lower than other values measured in urban areas of Spain and Europe. High eBC concentrations found in winter are associated with an increase in emissions from anthropogenic sources in combination with lower mixing layer heights and frequent stagnant conditions. The pronounced diurnal variability suggests a strong influence from local sources. AAE had an average value of 1.26 ± 0.22 which implies that both fossil fuel combustion and biomass burning influenced optical aerosol properties. This also highlights biomass combustion in suburban areas, where the use of wood for domestic heating is encouraged, as an important source of eBC. All data treatment was gathered using SCALA© as atmospheric aerosol data management support software program. [ABSTRACT FROM AUTHOR]

Since the Directive 2013/39/EU included terbutryn to the list of priority substances of all water bodies, a previous method based on dispersive liquid–liquid micro-extraction (DLLME) for the determination of triazines in seawater has been modified. The main change consisted on the use of tandem mass spectrometry instead of diode array as detection technique. Due to the higher sensitivity of mass detector, sample volume was reduced and extraction solvent volume was optimized. The optimum extraction conditions were 5 mL of sample, 50 µL of 1-octanol and an agitation step instead of disperser solvent. The obtained analytical recoveries (73%–101% with relative standard deviations below 4%) meeting the requirements. The limits of quantification (between 0.016 and 0.021 µg L−1) were more than 10 times lower than the limit set by the European Directive 2013/39/EU for terbutryn (0.34 µg L−1). The proposed method was applied to the determination of the target compounds in seawater samples from A Coruña (Galicia, NW of Spain). [ABSTRACT FROM AUTHOR]

Nowadays the consumption of so-called superfoods and nutritional supplements represents a new growing trend in the field of human nutrition. It's generally accepted that superfoods contain high levels of much-needed vitamins, essential fatty acids and minerals. Compounds of toxicological interest such as toxic elements could be also incorporated. Thus, the knowledge of the elemental composition and its dietary intakes are required for quality standards establishment of those superfood and related products. Several elements including major, minor and trace elements were analysed in selected foods (Brazil nut, golden berries, heart of palm and dietary supplements containing acai fruit) harvested in the Amazon region. Target elements were measured by inductively coupled plasma-mass spectrometry after a microwave assisted acid digestion pre-treatment. The accuracy of the proposed method were verified using Certified Reference materials and analytical recoveries tests. Ba, Ca, K, Mg and P (from 0.25 to 22387 µg g−1) are the major elements in selected samples. While Al, Cd, Co, Cr, Li, Pb and Sn (from < 0.01 to 3.02 µg g−1) are found at trace levels. Toxic metals (As, Be, Bi, Mo, Sb, Tl, V and W) concentrations in selected food samples are lower than quantification limits. Dietary element intakes were also, estimated and compared with recommended dietary allowances and upper tolerable levels. The distributions of the elements between lipid and lipid-free fractions of Brazil nut and golden berries were investigated. Element contents in the lipid fraction were lower than 1.8% and 8.4% for Brazil nut and golden berry, respectively. [ABSTRACT FROM AUTHOR]

Environmental context: Polycyclic aromatic hydrocarbons (PAHs) are widespread organic pollutants that tend to accumulate in soil. We developed an environmentally friendly analytical method for PAHs to evaluate human health risks associated with their presence in soils. The method is feasible for the analysis of soils with widely varying PAH contamination levels, and is well suited to environmental monitoring studies of relevance to human health. A microwave-assisted extraction, with a dispersive solid-phase purification step followed by programmed temperature vaporisation–gas chromatography–tandem mass spectrometry, is proposed as an environmentally friendly, simple and cheap analytical method for polycyclic aromatic hydrocarbons (PAHs) in soil. Different extraction and clean-up operating variables were tested to achieve satisfactory analytical performances: trueness from 92 to 114 %, limit of quantification (LOQ) from 0.4 to 2 µg kg−1 for most PAHs and intermediate precision, calculated as relative standard deviation (RSD), below 10 %. The method was validated using both Certified Reference Material and real soil samples collected at sites subjected to different human activities. PAH contents ranged from 0.11 (in holm oak forest soil) to 1 mg kg−1 d.w. (in an industrial soil) according to the anthropic gradient. The soil PAH contents measured were used to estimate the risk to human health, which suggested the exposure to the PAHs in soil as a potential risk for human health, especially at the industrial site. The feasibility of the method for soils with different PAH contamination degrees makes it relevant in monitoring programs. Environmental context. Polycyclic aromatic hydrocarbons (PAHs) are widespread organic pollutants that tend to accumulate in soil. We developed an environmentally friendly analytical method for PAHs to evaluate human health risks associated with their presence in soils. The method is feasible for the analysis of soils with widely varying PAH contamination levels, and is well suited to environmental monitoring studies of relevance to human health. [ABSTRACT FROM AUTHOR]

One of the fundamental stages in planning and developing any interlaboratory comparison is the selection and preparation of the test items to be distributed to the participants. In the case of compositional testing of textile materials, it is essential (1) to correctly identify the nature of the fibres which composes the fabric and (2) to check the homogeneity of the each test item. The Galician Laboratory of Consumer Products organized a proficiency testing (PT) in 2016 for textile fibres. Initial preparatory work was carried out with the assistance of the University of A Coruña, to identify the nature of the textile fibres using several complementary techniques specified in ISO/TR 11827 (e.g. optical microscopy, scanning electron microscopy, solubility tests and infrared spectroscopy). The fibres were compared with those from reference fabrics which were supplied by the Institute of Textile Research and Industrial Cooperation of Terrassa (INTEXTER). After the complete identification of the fibres, an assessment of homogeneity of the fabrics was performed according to the requirements in ISO 13528. Subsequently, five PT items were distributed and analysed according to the requirements set by ISO 1833 parts 3, 4, 7, 11 and 12, respectively. Eighteen laboratories from nine countries reported results, and the statistical treatment of results was performed according to ISO 13528. The assigned values were established by consensus, while the uncertainties were evaluated using the Naji Plot. [ABSTRACT FROM AUTHOR]

The inorganic chemical composition (major ions and trace metals) of bulk deposition samples collected monthly with bulk collectors at seven Atlantic Coastal European cities (Galicia, Northwest of Spain) during wet season (September 2011 to March 2012) has been assessed and compared. Trace metals (Al, As, Ba, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sr, V and Zn) were analysed in soluble fraction and non-soluble fraction (after acid extraction) of the bulk deposition by inductively coupled plasma-mass spectrometry. Major inorganic ions (Cl, NO , SO , Na, K, Ca, Mg and NH ) were analysed in the soluble fraction of the bulk deposition by capillary zone electrophoresis. Univariate analysis (ANOVA and Multiple Range Test) according to the location of each sampling site was performed. Results also suggest a great influence of cleaner Atlantic air masses. After partition coefficients and enrichment factor estimation, similar sources could be assigned for the ionic and metal composition of bulk deposition at seven urban sites. [ABSTRACT FROM AUTHOR]

Levels, origins and potential risks due to different air pollutants (ozone, SO and particle-borne metals) in NW Spain were investigated in eight locations affected by different emission sources. All monitored locations suffered the influence of traffic and industrial emissions, being this influence more important in urban locations. Although average values of the estimated hazard index (HI) due to particle-borne metals showed values lower than one, maximum values of this parameter exceeded this safety limit in urban locations. In general, Ni and As were identified as those metals most contributing to the HI. Furthermore, the presence of industrial emission episodes produced a significant increase in the magnitude of the HI in two of the seven urban areas. Therefore, the frequency and intensity of these episodes should be further investigated. Finally, levels of airborne and particle-borne pollutants were integrated with the aim of providing a comprehensive assessment of health risk. According to an established indexing system, air quality can be classified from good to moderate, being the southern urban locations (the most densely populated and industrialised ones) presenting the worst values. However, either the high or the low influence of acute and chronic-effect pollutants on air quality depends on the location. [ABSTRACT FROM AUTHOR]

A comprehensive chemical characterisation of the ionic and metallic composition of PM fraction of suburban aerosol collected with high-volume aerosol samplers at a coastal suburban site of northwest Atlantic European is studied over a 1.5-year period (from March 2011 to August 2012). The monthly mean PM mass concentrations (after gravimetric measurement) ranged from 13 to 26 μg m. Eighteen samples, which provide information pertaining to the monthly variation in chemistry, were analyzed. Trace metals (Al, As, Ba, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sr, V and Zn) were analysed in PM fraction after acid extraction (total metallic concentration) and after sonication-assisted water extraction (aqueous soluble fraction). Major inorganic ions (Cl, NO , SO , Na, K, Ca, Mg, NH and CO ) were also analysed in the aqueous fraction of PM. Trace metal extractability in water was in the range 50-67 % with exception of Al (∼2 %), Fe (∼4 %) and Cr (∼18 %). After univariate, cluster (CA) and principal component (PCA) analyses and air mass backward trajectory analysis, marine, crustal and anthropogenic (including road traffic) sources were found for the inorganic composition of PM. Results also suggest a great influence of cleaner Atlantic air masses and ubiquitous sources for K, Mg, Fe, Ni and V. [ABSTRACT FROM AUTHOR]

A simple, effective, and economic method for determination of nine triazines (ametryn, atrazine, cyanazine, prometryn, propazine, simazine, simetryn, terbuthylazine, and terbutryn) in drinking water based on solid-phase extraction (SPE) followed by high-performance liquid chromatography-diode array detection (HPLC-DAD) was developed. A specialized solid phase (Oasis HLB) was used, and the parameters that may affect the efficiency of SPE were optimized. The limits of detection (ranged from 0.010 to 0.023 µg L−1) were satisfactory and allow the determination of triazines at the levels required by European Union legislation. Repeatability (2.4–7.6%) and intermediate precision (0.9–11.0%) calculated at 0.1 µg L−1(legislation level) were adequate. The accuracy calculated as the average recovery of spiked tap and mineral waters was higher than 86% for all compounds. The developed method also could be used for undergraduate laboratory experiments because it acquaints students with solution preparation, solid phase extraction procedure, and HPLC-DAD technique. [ABSTRACT FROM PUBLISHER]

A fully automated method consisting of microextraction by packed sorbent (MEPS) coupled directly to programmed temperature vaporizer-gas chromatography-mass spectrometry (PTV-GC-MS) has been developed to determine the 12 chlorobenzene congeners (chlorobenzene; 1,2-, 1,3-, and 1,4-dichlorobenzene; 1,2,3-, 1,2,4-, and 1,3,5-trichlorobenzene; 1,2,3,4-, 1,2,3,5-, and 1,2,4,5-tetrachlorobenzene; pentachlorobenzene; and hexachlorobenzene) in water samples. The effects of the variables on MEPS extraction, using a C18 sorbent, and the instrumental PTV conditions were studied. The internal standard 1,4-dichlorobenzene d4 was used as a surrogate. The proposed method afforded good reproducibility, with relative standard deviations (RSD %) lower than 12 %. The limits of detection varied between 0.0003 μg L for 1,2,3,4-tetrachlorobenzene and 0.07 μg L for 1,3- and 1,4-dichlorobenzene, while those of quantification varied between 0.001 μg L and 0.2 μg L for the same compounds. Accuracy of the proposed method was confirmed by applying it to the determination of chlorobenzenes in different spiked water samples, including river, reservoir, and effluent wastewater. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The monitoring of organochlorine pesticides has raised a great concern in the last years due to their toxicity (some of them are carcinogenic and endocrine disruptor compounds) and persistence. European Directive 2008/105/EC establishes very restrictive levels for organochlorine pesticides in surface waters. Therefore, simple, fast, highly sensitive and low cost analytical methods are required to detect and quantify these pollutants in water. In the present work, four procedures for extraction and determination are proposed and compared for the analysis of 28 organochlorine pesticides in tap, surface and sea waters. The suitability of each method of analysis was evaluated for each kind of water. The extraction methods proposed were: two solid-phase extraction methods using C18laminar disk and Oasis HLB cartridges, a solid-phase microextraction procedure using a polydimethylsiloxane/divinylbenzene (PDMS/DVB) fibre, and a micro liquid–liquid extraction procedure using ethyl acetate as solvent. Determination of pesticides was performed by large volume on-column injector-gas chromatography-electron capture detection (LVOCI-GC-ECD), splitless-GC-ECD and GC-MS (mass spectrometry). All methods present a good sensitivity with method detection limits lower than 10 ng L−1, good accuracy with recoveries between 75 and 120% (with some exceptions) and good precision (relative standard deviations <15%), according to the Commission Decision 2002/657/EC criteria. The advantages and disadvantages of each method are discussed in terms of the green chemistry principles, the figures of merit and the matrix effect. This work tries to be a useful guidance for routine and control analysis laboratories. [ABSTRACT FROM AUTHOR]

The feasibility of pressurized chelating solvents [ethylenediaminotetracetic acid (EDTA) dipotassium salt, 1,10-ortho-phenanthroline (PHEN), 8-hydroxyquinoline (8HQ), chloramine-T (CT), 1,1,1-trifluoro-2,4-pentanedione (H(fta)), 2,2′-azobis-(2-methylpropionamidine) dihydrochloride (AMPAHC) and 1,5-diphenylcarbazone (DFC)] has been investigated from a novel aspect to speed up metals leaching from atmospheric particulate matter (PM10). The target elements (Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Na, Ni, Pb, Sr, V and Zn) have been evaluated by inductively coupled plasma-optical emission spectrometry (ICP-OES). The highest metal recoveries (within the 85–100% range) were found when using EDTA. Variables inherent to pressurized liquid extraction (temperature, chelating solvent concentration, static time, pressure, number of cycles, dispersing agent mass, flush volume and purge time) were simultaneously studied by applying a Plackett–Burman design (PBD) as the screening method. Results showed statistical significance for some factors such as extraction temperature and EDTA concentration. The static time and the number of cycles were statistically non-significant for most of the elements, meaning that the pressurized leaching procedure can be finished after 12 min (5 min for pre-heating the extraction cell at 100 °C plus 5 min of static time plus 1 min of purge time plus 1 min of end relief time). In addition, the presence of dispersing agent was not necessary, which reduces the time for filling of the cells. Quantitative recoveries for all metals were reached under the following extraction conditions: 40 mM EDTA, extraction temperature of 100 °C, pressure of 1000 psi, static time of 5 min and one extraction cycle. Analytical performances, such as limits of detection and quantification and repeatability of the over-all procedure, have been established. Finally, results obtained by EDTA-based pressurized liquid extraction have been found to be statistically comparable with those obtained after conventional acid digestion with nitric, hydrofluoric and perchloric acids. [ABSTRACT FROM AUTHOR]

A selective analytical method for the determination of nine organophosphate triesters and triphenylphosphine oxide (TPPO) in outdoor particulate matter is presented. It involves a fully automated pressurised liquid extraction (PLE) step, integrating an alumina clean-up process, and subsequent determination by large-volume injection gas chromatography–positive chemical ionisation–tandem mass spectrometry (LVI-GC–PCI–MS/MS). The extraction variables (solvent, amount of adsorbent, temperature, time and number of cycles) were optimised using a multicriteria strategy which implements a desirability function that maximises both extraction and clean-up efficiencies while searching for the best-compromise PLE conditions. The final method affords quantification limits of between 0.01 and 0.3 μg g−1 and recoveries of >80%, with the exceptions of the most polar analytes, TCEP and TPPO (~65%) for both urban dust and PM10 samples. Moreover, the method permitted the levels of these compounds in dust deposited outdoors (between LOD and 0.5 μg g−1 for TEHP) and PM10 samples (between LOD and 2.4 μg m−3 for TiBP) to be measured and reported for the first time. [ABSTRACT FROM AUTHOR]

An analytical method has been developed for determination of major (Ca, K, Mg, and Na) and trace elements (As, Cd, Co, Li, Ni, and Sr) in human scalp hair. The proposed method includes a novel, simple, rapid, highly efficient, and automated metal-leaching procedure, by pressurized-liquid extraction (PLE), combined with a rapid simultaneous detection system—inductively coupled plasma–optical-emission spectrometry (ICP–OES). PLE is one of the most promising recently introduced sample-preparation techniques, with the advantages of reducing solvent consumption and enabling automated sample handling. The operating conditions for PLE, including concentration of the extraction solvent, extraction temperature, static time, number of extraction steps, pressure, mean particle size, diatomaceous earth (DE) mass/sample mass ratio, and flush volume were studied using an experimental design (Plackett–Burman design, PBD). The optimum conditions were use of 0.75 mol L−1 acetic acid as extracting solution and powdered hair samples thoroughly mixed with DE, as a dispersing agent, at a DE mass/sample mass ratio of 4. Extraction was performed at room temperature and an extraction pressure of 140 atm for 5 min in one extraction step. The flush volume was fixed at 60%. The PLE-assisted multi-element leaching proposed is complete after 7 min (5 min static time plus 1 min purge time plus 1 min end relief time). Under the optimised conditions the figures of merit, for example limits of detection and quantification, repeatability of the over-all procedure, and accuracy, were evaluated. Analysis of GBW-07601 (human hair) certified reference material revealed accuracy was good for the target elements. The optimised method was finally applied to several human scalp-hair samples. [ABSTRACT FROM AUTHOR]

A method to determine 21 organochlorine pesticides in horticultural samples (lettuce, pepper, tomato, spinach and potato) based on microwave assisted extraction (MAE) followed by solid-phase extraction (SPE) clean-up is described. After extraction with hexane?:?acetone (50?:?50), a carbon cartridge was employed for the clean-up step. Pesticides were eluted with 5?mL of hexane?:?ethyl acetate (80?:?20) and determined by gas chromatography and electron capture detection (GC-ECD). Results were confirmed by GC-MS analysis. Analytical recoveries obtained were ca. 100% for most of the studied pesticides with the proposed method in each analysed matrix. The method was applied to analyse 35 commercial samples from A Coruña (NW Spain); only two samples contained pesticide residues, but none of them exceeded the MRLs established by EU legislation. [ABSTRACT FROM AUTHOR]

The hydrocarbon composition of atmospheric particulate matter from A Coruña city (Northwest Spain) has been studied. TSP (total suspended particulate) and PM10 (particulate matter with aerodynamic diameter <10 µm) samples were taken over 7 and 4 months at two stations located in residential and industrial sectors of A Coruña city, respectively. The levels of hydrocarbons found in atmospheric particulate samples of A Coruña city are higher than the ones found in other cities over the world. Ratios between the analysed compounds and their sources were established. Both anthropogenic and biogenic origins were found. [ABSTRACT FROM AUTHOR]

Currently, gas chromatography is the most common analytical technique for natural gas (NG) analysis as it offers very precise results, with very low limits of detection and quantification. However, it has several drawbacks, such as low turnaround times and high cost per analysis, as well as difficulties for on-line implementation. With NG applications rising, mostly thanks to its reduced gaseous emissions in comparison with other fossil fuels, the necessity for more versatile, fast, and economic analytical methods has augmented. This work summarizes the latest advances to determine the composition and physico-chemical properties of regasified liquid natural gas, focusing on infrared spectroscopy-based techniques, as well as on data processing (chemometric techniques), necessary to obtain adequate predictions of NG properties. [ABSTRACT FROM AUTHOR]

Due to the exponential growth of the SARS-CoV-2 pandemic in Spain (2020), the Spanish Government adopted lockdown measures as mitigating strategies to reduce the spread of the pandemic from 14 March. In this paper, we report the results of the change in air quality at two Atlantic Coastal European cities (Northwest Spain) during five lockdown weeks. The temporal evolution of gaseous (nitrogen oxides, comprising NOx, NO, and NO2; sulfur dioxide, SO2; carbon monoxide, CO; and ozone, O3) and particulate matter (PM10; PM2.5; and equivalent black carbon, eBC) pollutants were recorded before (7 February to 13 March 2020) and during the first five lockdown weeks (14 March to 20 April 2020) at seven air quality monitoring stations (urban background, traffic, and industrial) in the cities of A Coruña and Vigo. The influences of the backward trajectories and meteorological parameters on air pollutant concentrations were considered during the studied period. The temporal trends indicate that the concentrations of almost all species steadily decreased during the lockdown period with statistical significance, with respect to the pre-lockdown period. In this context, great reductions were observed for pollutants related mainly to fossil fuel combustion, road traffic, and shipping emissions (−38 to −78% for NO, −22 to −69% for NO2, −26 to −75% for NOx, −3 to −77% for SO2, −21% for CO, −25 to −49% for PM10, −10 to −38% for PM2.5, and −29 to −51% for eBC). Conversely, O3 concentrations increased from +5 to +16%. Finally, pollutant concentration data for 14 March to 20 April of 2020 were compared with those of the previous two years. The results show that the overall air pollutants levels were higher during 2018–2019 than during the lockdown period. [ABSTRACT FROM AUTHOR]

Atmospheric particle-bound mercury (PHg) quantification, at a pg m−3 level, has been assessed in particulate matter samples (PM10) at several sites (industrial, urban and sub-urban sites) of Atlantic coastal European region during 13 months by using a direct thermo-desorption method. Analytical method validation was assessed using 1648a and ERM CZ120 reference materials. The limits of detection and quantification were 0.25 pg m−3 and 0.43 pg m−3, respectively. Repeatability of the method was generally below 12.6%. PHg concentrations varied between 1.5–30.8, 1.5–75.3 and 2.27–33.7 pg m−3 at urban, sub-urban and industrial sites, respectively. PHg concentration varied from 7.2 pg m−3 (urban site) to 16.3 pg m−3 (suburban site) during winter season, while PHg concentrations varied from 9.9 pg m−3 (urban site) to 19.3 pg m−3 (suburban site) during the summer. Other trace elements, major ions, black carbon (BC) and UV-absorbing particulate matter (UV PM) was also assessed at several sites. Average concentrations for trace metals (Al, As, Bi, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Sb, Si, Sr, V and Zn) ranged from 0.08 ng m−3 (Bi) at suburban site to 1.11 µg m−3 (Fe) at industrial site. Average concentrations for major ions (including Na+, K+, Ca2+, NH4+, Mg2+, Cl−, NO3− and SO42−) ranged from 200 ng m−3 (K+) to 5332 ng m−3 (SO42−) at urban site, 166 ng m−3 (Mg2+) to 4425 ng m−3 (SO42−) at suburban site and 592 ng m−3 (K+) to 5853 ng m−3 (Cl−) at industrial site. Results of univariate analysis and principal component analysis (PCA) suggested crustal, marine and anthropogenic sources of PHg in PM10 at several sites studied. Toxicity prediction of PHg, by using hazard quotient, suggested no non-carcinogenic risk for adults. [ABSTRACT FROM AUTHOR]

A simple method based on solid-phase extraction combined with liquid chromatography for simultaneous determination of nine triazine herbicides (ametryn, atrazine, cyanazine, prometryn, propazine, simazine, simetryn, terbuthylazine, and terbutryn) in surface water samples was developed and validated. Under optimized conditions, 50 mL of water sample was pumped through the Oasis HLB cartridge, and triazines were eluted with 3 mL acetone. Finally the extract was concentrated to dryness, reconstituted with 1 mL methanol : water (1 : 1) and injected into the HPLC-DAD system. The stability of the herbicides on the cartridges at -18 and 4°C was also evaluated, and the recoveries obtained after three weeks of storage were satisfactory for all compounds. The analytical features of the proposed method were satisfactory: repeatability and intermediate precision were <10% and recoveries in spiked river water and seawater samples were higher than 93% for all compounds studied. Limits of quantification (varied from 0.46 to 0.98 µg L⁻¹) were adequately allowing the determination of these compounds at the levels requested by the 2008/105/EC Directive. Finally, this method was applied to the analysis of 50 seawater samples from Galicia (northwest Spain). [ABSTRACT FROM AUTHOR]