Climate change impacts on environmental and human exposure to mercury in the arctic.

This paper reviews information from the literature and the EU ArcRisk project to assess whether climate change results in an increase or decrease in exposure to mercury (Hg) in the Arctic, and if this in turn will impact the risks related to its harmful effects. It presents the state-of-the art of knowledge on atmospheric mercury emissions from anthropogenic sources worldwide, the long-range transport to the Arctic, and it discusses the likely environmental fate and exposure effects on population groups in the Arctic under climate change conditions. The paper also includes information about the likely synergy effects (co-benefits) current and new climate change polices and mitigation options might have on mercury emissions reductions in the future. The review concludes that reductions of mercury emission from anthropogenic sources worldwide would need to be introduced as soon as possible in order to assure lowering the adverse impact of climate change on human health. Scientific information currently available, however, is not in the position to clearly answer whether climate change will increase or decrease the risk of exposure to mercury in the Arctic. New research should therefore be undertaken to model the relationships between climate change and mercury exposure.

Determination of SCFAs in water using GC-FID. Selection of the separation system.

In the present study, an analytical procedure was developed for the determination of short-chain fatty acids (SCFAs) in landfill leachate and municipal wastewater employing injection of aqueous samples to gas chromatograph with flame ionization detector (GC-FID). Chromatographic conditions such as a separation system, injection volume, oven temperature program were investigated and selected. With two columns, one with a polar (polyethylene glycol) and one with a non-polar (dimethylpolisiloxane) stationary phase, good separation of SCFAs, containing from 2 to 8 carbon atoms, was achieved. The sample volume was 2 µL and the temperature program 80°C (30 s) then 7 °C min(-1) to 220 °C (2 min). LOQs values were below 0.25 mg L(-1). The concentrations of the acids in the landfill leachate studied ranged from 0.45±0,059 (average ± extended uncertainty) mg L(-1) for pentanoic acid to 15.2±0.73 mg L(-1) for ethanoic acid. Concentrations of SCFAs in the municipal wastewater were lower than LOQs.

Development of headspace-gas chromatography-flame ionization detection procedure to determine volatile fatty acids in zoo organic waste leachates.

In order to determine volatile fatty acids (short chain monocarboxylic acids with 2 to 6 carbon atoms in a molecule) in leachates formed in organic waste piles a procedure based on static headspace (HS) coupled with gas chromatography (GC) have been proposed and optimized. The conditions of HS extraction and sample introduction into a gas chromatograph as well as of chromatographic separation were considered. Using flame ionization detection LODs were of the order of 0.02-0.37 mg/L. The analyzed leachate collecting on and close to a zoo organic waste pile contained VFAs (Volatile Fatty Acids) at a concentration ranging from 5.5 mg/L to 0.88 g/L and from below LOD to 10.1 mg/L for pool water at some distance from the pile, respectively.

Application of gas chromatography-mass spectrometry preceded by solvent extraction to determine volatile fatty acids in wastewater of municipal, animal farm and landfill origin.

This study describes extraction of selected volatile fatty acids (VFAs) (containing from 2 up to 8 carbon atoms) with methyl-tert-butyl ether (MTBE) from polluted aqueous samples followed by separation, identification and quantification by gas chromatography coupled with mass spectrometry (GC-MS). Extraction parameters such as time and number of extractions, volume ratio, effect of acidification and salt addition were optimized with respect to recovery, enrichment factor and repeatability. The VFAs studied were separated using an open tubular capillary column Stabilwax-DA (crossbond polyethylene glycol treated with nitroterephtalic acid). The limits of quantitation (LOQ) of the procedure developed were on the level of 0.1 to 0.5 mg L(-1). The analysis of real samples of municipal raw and treated wastewater, animal farms wastewater, and also landfill leachates showed that always dominant was acetic acid. The content of VFAs in animal farms wastewater was a few times higher than in municipal wastewater and in municipal solid waste landfill leachates. In surface and ground water close to municipal landfill only acetic acid was detected at higher concentrations in outflow than inflow water. This indicates that slight leakage from the landfill must have occurred.

Application of headspace solid-phase microextraction followed by gas chromatography-mass spectrometry to determine short-chain alkane monocarboxylic acids in aqueous samples.

In this study, a procedure was developed to determine short-chain alkane monocarboxylic acids (SCMAs) in aqueous samples using headspace solid-phase microextraction (HS-SPME) followed by gas chromatography (GC) coupled with mass spectrometry (MS). A Stabilwax-DA capillary column (30 m × 0.32-mm inner diameter, 0.50-µm film thickness) was used for GC separation and a 60-µm poly(ethylene glycol) fiber was used to isolate SCMAs from water and introduce them into the gas chromatograph. Parameters of HS-SPME, analyte desorption, and GC-MS analysis were selected and an analytical procedure was proposed. Limits of quantitation were on the order of about 0.2 mg L(-1). As an example of the application of the procedure, SCAMs were determined in municipal wastewater at different steps of treatment.