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Mercury exposure constitutes an acute risk to human health and the environment. Driven by the requirement to monitor trace-level mercury, we report a highly sensitive mercury(II) DNA sensor enhanced by silver(I) activation, followed by mercury(II)-specific oligonucleotides (MSO) molecular configuration switch and mercury(II)-modulated FRET. Activating the MSO strands with silver(I), mismatched cytosine–silver(I)–cytosine bridges induce individual MSO strands to fold readily in response to mercury(II) resulting in enhanced fluorescence signal. The structural switches were studied by 2D 1H–1H NOESY and TOCSY NMR spectroscopy, and 260 nm absorbance. The signal decreases with increasing mercury(II) concentration from 100 pM to 0.1 mM. The approach affords outstanding mercury(II) selectivity over other environmentally associated metals. Furthermore, the methodology was deployed for detection of mercury(II) in spiked pond waters with 97.9–100.6% recovery. The simple and feasible format has great potential for developing a cost effective and useful tool for environmental monitoring.

An analytical method to determine tin concentrations in natural samples, by coupling atomic fluorescence spectrometry, hydride generation and flow injection system was developed. The sample digestion procedure and the conditions of hydride generation were fully optimized. The best conditions for the generation of SnH4 were obtained with NaBH4 4% (m v-1) and HCl 0.6 mol L-1. The optimized flow rates were 1.2 mL min-1 for sample, 1.2 mL min-1 for HCl and 1.6 mL min-1 for NaBH4 solution. The sample volume was 500 µL. The best acid volume for digestion of solid samples was stablished to be 3 mL HNO3 + 1 mL HCl. The accuracy of the method was established by the analysis of certified reference materials and by comparative determinations, using inductively coupled optical emission spectrometry. The approach developed was shown to offer a robust method with excellent accuracy and precision for the determination of Sn in environmental samples. Finally, the method was applied to analyse the soil, sediment and water samples, collected in area under anthropogenic activities: processing area of cassiterite in Corumbataí/SP. The obtained data indicated that there was alteration in the natural quality of the environment as a result of the activities developed in that site

The development, optimisation and assessment of novel automated analytical equipment for cold vapour/hydride generation is described. Various designs of gas-liquid separators (GLS) were investigated for continuous flow hydride generation, including a glass 'U' tube GLS, a silicone rubber membrane GLS and a microporous polytetrafluoroethylene membrane GLS. P S Analytical Ltd, Arthur House, B4 Chaucer Business Park, Watery Lane, Kernsing, Sevenoaks, Kent TNI5 6QY

In order to control the efficiency of an industrial facility for removal of mercury from mercury contaminated natural gas ; a comprehensive technological and environmental mercury monitoring programme was established. Several studies focused on mercury pollution identification and quantification with emphasis on the ecological, animal and human biomonitoring was performed in the vicinity of the natural gas processing plant. The research results of mercury concentration in the plant (mosses), free leaving animals (hares and pheasants) and human samples (blood, urine) will be presented.

Mercury’s potentially harmful effect on humans, animals and on the ecological system as a whole as well as the risk regarding mercury's corrosive effects to the very sophisticated and expensive process material, equipment and catalysts is making its removal an imperative. Hg must be removed in order to obtain: - safe and reliable operations of process plants, - fulfil the requirements related to product specifications, - protect the human working and living environment

The major source of MeHg exposure of general population represents seafood consumption. Although is well known that the highest levels of total mercury (THg) and methyl mercury (MeHg) were found in organisms at the top of the food chain, THg, MeHg levels in fish vary greatly between and within species depending also on fish origin. Moreover, the EU is one of the largest seafood markets. Fish bought at the same food market can origin from fishing areas of all parts of the world and fish can be farmed or from wild fisheries. Therefore, in order to assess Hg exposure through fish consumption, THg and MeHg levels were determined in fish consumed by Slovenian (Ljubljana), Italian (Trieste) and Croatian (Rijeka) population and compared to data obtained from other European countries. The data about the most frequently consumed species of fish were assessed with detailed food frequencies questionnaires filled by the most susceptible population (pregnant women) from Slovenia (n=584), Italy (n=900) and Croatia (n=234). The samples of the most frequently consumed species of fish were then collected from the fish markets where these pregnant women were probably buying the fish. In addition, THg and MeHg levels were also determined in the same species of fish from farmed and wild fisheries available on the Slovenian market. The mean THg values were 21 ng/g (Min 11 ng/g, Max 62 ng/g) in fish from the Slovenian market, 164 ng/g (Min 17 ng/g, Max 1220 ng/g) in fish from the Italian market and 143 ng/g (Min 8 ng/g, Max 587 ng/g) in fish from the Croatian market. Moreover, in our study most of the fish bought by Slovenian women were farmed, while Croatian and Italian women ate farmed fish and fish from wild fisheries.