Comprehensive two-dimensional gas chromatography, a valuable technique for screening and semiquantitation of different chemical compounds in ultrafine 30 nm and 50 nm aerosol particles

Comprehensive two dimensional gas chromatography-time-of-flight mass spectrometry (GC×GC-TOF-MS) was used for screening and semiquantitation of semivolatile organic compounds in aerosol particles. As the volatility was a prerequisite parameter for the analysis, some compounds were transformed via derivatization such as silylation into more volatile ones. The identification of the analytes was made by comparing the GC retention indices and the TOF mass spectra with the NIST and the Golm metabolome database reference libraries. The data treatment was simplified by exploiting an additional classification of the identified compounds, namely the main functional group or specific element present in the molecule leading to different groups of compounds. This methodology was applied to identify compounds in 30 ± 4 nm, 50 ± 5 nm and total suspended particles (TSP) collected during spring and autumn of 2009 and summer of 2010 at the Station for Measuring Forest Ecosystem Atmosphere Relations (SMEAR II) at Hyyti?l? (Finland). The number of identified compounds was higher than 400, which were the most relevant compounds present in the samples, in terms of concentrations. The analysis of aerosol particles of different sizes, collected simultaneously, revealed that the number of compounds increased with the particle size whereas the normalized response factor decreased in most of the cases, aldehydes being an exception. This decrease could be associated with the formation or aggregation of new compounds onto the particles when they grow in the atmosphere.     

Finnish stakeholder engagement in the restoration of a radioactively contaminated food supply chain

An expert group was established in 2001 representing various organisations and authorities responsible for primary production, food processing, the distribution and consumption of foodstuffs, food safety and availability, catering and extension services, nature conservation, research into environmental impacts, and the media. The aim was to strengthen networking and improve the stakeholder response to accidental radioactive contamination of rural areas through participation in the FARMING network project. A hypothetical contamination of a large milk-producing area provided a suitable framework for evaluation of actions ensuring clean feeding of dairy cows during grazing. The following year the group received a compilation of rural countermeasures and waste disposal methods, described by the STRATEGY project. The robust, uncomplicated approach of the evaluation meetings was fruitful and efficient, and the multidisciplinary group was capable of taking shared views on various measures after updating their knowledge together. High priority was given to measurements of radioactivity and the provision of information and advice to a wider audience.     

Analyses of known and new types of polyhalogenated aromatic substances in oven ash from recycled aluminium production

Persistent aromatic bromine, chlorine and mixed chlorine-bromine compounds were analysed from recycled aluminium smelter (ALS) ashes to explore the impact of brominated flame retardants (BFR) on their formation. Polybrominated diphenyl ethers (PBDE) were the most abundant original BFRs found. Induction furnace ash contained tetra- to octa-BDEs about 2000ng g(-1) in similar congener ratios as the original scrap, but contents of nona- and deca-BDEs were only 25 and 5ng g(-1) indicating their significant degradation in ALS process. In the most non-polar fraction, PCB levels and profiles were similar as earlier ALS ash samples in 1990s. The highest PCB level measured was that of deca-CB (450ng g(-1)) in the induction furnace ash. In this fraction, bromo compounds were non-detectable (<5ng g(-1)). Fraction of the most polar compounds (from reversed toluene elution of carbon column ("dioxin fraction") contained PCDDs, PCDFs and polychlorinated dibenzothiophenes (PCDTs) in similar amounts and congener profiles as earlier investigated ALS ash samples. Bromine-containing dioxin and furan congeners were not detected. From individual PCDDs and PCDFs, octaCDF was the most abundant (205ng g(-1)) in induction furnace ash. In this fraction, the original BFR, tetrabromo-bisphenol-A, was identified. Its level in the induction furnace ash was approximated to be 388ng g(-1). In addition, 12 novel brominated and chlorinated compounds were found as abundant (8-441ng g(-1) in the induction furnace ash) contaminants from the fraction. Four of them were bisphenol derivatives, five biphenylols, then octachlorofluorenone (OCFL) and octachlorobiphenylene (OCBP). Their structures or structure types were deduced from total low-resolution EI mass spectra by theoretical isotope cluster simulation (ICLU) and through known fragmentation rules.     

A wood preservative metabolite in river water

- A previously unknown pollutant in river water was identified to be 2-mercaptobenzothiazole (2-MBT) by interpretation and simulation of its GC/LRMS spectrum. Further GC/HRMS measurement of the isotope composition of the molecular ion verified this structure. 2-MBT is a well-known agent for corrosion inhibition and a stable metabolite of several other benzothiazoles. The present 2-MBT trace was most probably a metabolite of the wood preservative TCMTB which leaked from an upstream sawmill. The metabolite had been detected earlier in urine of the sawmill workers, but now was identified in the recipient water environment for the first time.     

Polychlorinated dibenzothlophenes in bleached pulp mill effluents

Polychlorinated dibenzothiophenes, PCDBTs, have been analysed with HRGC/HRMS from different bleached pulp mill effluents. 2,3,7,8-TeCDBT was found to be the dominating TeCDBT isomer in some samples. The estimated concentrations of the TeCDBTs in the samples were < 1 to 60 pg/L. PeCDBTs and other higher chlorinated PCDBTs were not found (< 1 pg/L).     

PCDTs in the environment

Polychlorinated dibenzothiophenes (PCDTs) are sulfur analogues of polychlorinated dibenzofurans. Recently, PCDTs have been found in stack gas and fly ash samples, pulp mill effluents, sediments and in some aquatic organisms. PCDTs have been analyzed by high resolution GC/MS and by other GC-MS techniques. Combustion is until now the major known source of PCDTs in the environment. Tri-, tetra- and pentaCDTs in concentrations approaching those of PCDTs have been analyzed in some samples from waste incineration and metal reclamation. Concentrations of PCDTs in pulp mill effluents have been found to be quite low. 2378-TeCDT was found to be the major TeCDT isomer in some pulp mill effluents. Preliminary toxicological investigations have shown that PCDTs possess some kind of dioxin type toxicity.     

Identification and level estimation of chlorinated neutral aromatic sulfur compounds and their alkylated derivatives in pulp mill effluents and sediments

Seven effluent samples from a modern pulp mill, in which chlorine and chlorine dioxide bleaching is used, and five sediment samples from the recipient watercourse were investigated for polychlorinated dibenzothiophenes (PCDBTs), polychlorinated thianthrenes (PCTAs), polychlorinated diphenylsulfides (PCDPSs) and for alkylated derivatives of these. Mainly di-, tri-, tetra- and pentachlorinated congeners were studied. Particles and filtrates from the effluents were analyzed separately. The concentration levels of the nonalkylated compounds were found to be higher in the filtrates than in the particles. Trichlorinated dibenzothiophenes and thianthrenes were found as the major congeners. Pentachlorinated derivatives were not found. Alkylated di- and trichlorodibenzothiophenes were detected in some samples, while alkylated chlorinated thianthrenes and diphenylsulfides were nondetectable. The estimated concentration levels of the compounds detected were in the range of 40–2700 pg/L in the pulp mill effluents and in the range of 2–40 pg/g dry weight in the sediments. Mixtures of methylated di- and trichlorodibenzothiophenes used as references in analyses were prepared from methylchlorobiphenyls. Some new pure model compounds were obtained by HPLC fractionation of the chlorination mixture of dibenzothiophene. Structures of these were determined by ¹H NMR.     

Aerosol particle number concentration measurements in five European cities using TSI-3022 condensation particle counter over a three-year period during health effects of air pollution on susceptible subpopulations

In this study, long-term aerosol particle total number concentration measurements in five metropolitan areas across Europe are presented. The measurements have been carried out in Augsburg, Barcelona, Helsinki, Rome, and Stockholm using the same instrument, a condensation particle counter (TSI model 3022). The results show that in all of the studied cities, the winter concentrations are higher than the summer concentrations. In Helsinki and in Stockholm, winter concentrations are higher by a factor of two and in Augsburg almost by a factor of three compared with summer months. The winter maximum of the monthly average concentrations in these cities is between 10,000 cm(-3) and 20,000 cm(-3), whereas the summer min is approximately 5000-6000 cm(-3). In Rome and in Barcelona, the winters are more polluted compared with summers by as much as a factor of 4-10. The winter maximum in both Rome and Barcelona is close to 100,000 cm(-3), whereas the summer minimum is > 10,000 cm(-3). During the weekdays the maximum of the hourly average concentrations in all of the cities is detected during the morning hours between 7 and 10 a.m. The evening maxima were present in Barcelona, Rome, and Augsburg, but these were not as pronounced as the morning ones. The daily maxima in Helsinki and Stockholm are close or even lower than the daily minima in the more polluted cities. The concentrations between these two groups of cities are different with a factor of about five during the whole day. The study pointed out the influence of the selection of the measurement site and the configuration of the sampling line on the observed concentrations.     

Developing a circumpolar programme for the monitoring of Arctic terrestrial biodiversity

The Arctic is undergoing biological and environmental changes, and a coordinated effort to monitor is critical to detect these changes. The Circumpolar Biodiversity Monitoring Programme (CBMP) of the Arctic Council biodiversity working group, Conservation of Arctic Flora and Fauna (CAFF), has developed pan-Arctic biodiversity monitoring plans that aims to improve the ability to detect and report on long-term changes. Whilst introducing this special issue, this paper also presents the making of the terrestrial monitoring plan and discusses how the plan follows the steps required for an adaptive and ecosystem-based monitoring programme. In this article, we discuss how data on key findings can be used to inform circumpolar and global assessments, including the State of the Arctic Terrestrial Biodiversity Report, which will be the first terrestrial assessment made by the CBMP. Key findings, advice for future monitoring and lessons learned will be used in planning next steps of pan-Arctic coordinated monitoring.     

Long-term observation of air pollution-weather/climate interactions at the SORPES station: a review and outlook

This work presents an overall introduction to the Station for Observing Regional Processes of the Earth System–SORPES in Nanjing, East China, and gives an overview about main scientific findings in studies of air pollution-weather/climate interactions obtained since 2011. The main results summarized in this paper include overall characteristics of trace gases and aerosols, chemical transformation mechanisms for secondary pollutants like O₃, HONO and secondary inorganic aerosols, and the air pollution–weather/climate interactions and feedbacks in mixed air pollution plumes from sources like fossil fuel combustion, biomass burning and dust storms. The future outlook of the development plan on instrumentation, networking and data-sharing for the SORPES station is also discussed.

Open image in new window