Abstract: The paper presents the results of the study of atmospheric aerosols in the Siberian region. This research was focused on studying the chemical and biological characteristics of both natural and pollution aerosols in this vast territory of the Asian part of the former Soviet Union (FSU). The data received within the frame of this project formed the basis for the evaluation of the impact of these aerosols on the Arctic region and the global climate. The Asian part of FSU is of scientific interest in the context of environmental chemistry, air pollution and study of atmospheric aerosols, The specific relevance of aerosol research in Siberia is as follows. There are areas that are very remote from industrial or densely populated centres, In these circumstances, aerosol characterization contributes to the definition of global continental “background”) or “baseline” aerosol, i.e, the aerosol which should occur in natural circumstances and on which all pollution is superimposed. Recently, in the context of global and long-term climatic changes, baseline aerosols and long-range transport of particulate air pollutants have become a topic of much debate, This is because it has been thought that aerosols might compensate for the well-known greenhouse effect to a significant. In this context, more and more attention is being paid to long-range effects of continental aerosols on the polar regions. Research in Norway and Alaska showed that Western or Central Siberia may be a very important source of pollutants affecting the air composition in the Arctic region. Cities and regions in south Siberia are enormously polluted by heavy metals, the level of pollution being many times higher than in the Western world, thus the health of local population is seriously affected. In most cases, gigantic point sources are in the area, which is simple from the viewpoint of environmental chemistry and unambiguous results should be obtained easily. Atmospheric deposition is a possible cause of the existence of heavy metals in the southern part of Lake Baikal. in the northern part of the lake, the environment is unpolluted. However in the southern part of the lake is considerably threatened by pollution from Baikalsk wood-pulp mill and industrial enterprises of Irkutsk, Angarsk,

Abstract: The chemical characterization of particulate matter inside and outside of confined bus shelters has been discerned for the first time. Transit patrons are at risk due to the close vicinity of densely trafficked areas resulting in elevated pollution footprints. Incomplete combustion processes, as well as exhaust and wear and tear emissions from public and personal transportation vehicles, are key contributors to degraded urban air quality and are often implicated as causal to various diseases in humans. Urban planning, therefore, includes efficient public transport systems to mitigate the effect. The bus rapid transit system was inaugurated in Curitiba to ensure dedicated traffic lanes, major bus interchanges and semi-confined bus stops called tube stations. To assess the chemical risk that the passengers are exposed to, an investigation of the aerosol inside and outside five of these tube stations was launched. Electron probe X-ray micro-analysis and X-ray fluorescence were used to determine the elemental composition of individual and of bulk particle samples. An aethalometer quantified the black carbon. Elemental concentrations inside the shelters were in general higher than outside, especially for traffic-related elements. The lead concentration exceeded the NAAS standard at times, although the average was below the guideline. The biogenic, organic and soot clusters showed the highest abundance for the city centre sites. The overall carcinogenic risk could be classed as moderate, and the risk was significant at two sites during one of the sampling campaigns. The non-carcinogenic risk is well below the significant value.

Abstract: Gold-sputtered microelectrodes with built-in gold reference and counter electrodes represent a promising platform for the development of disposable DNA sensors. Pretreating gold electrode surfaces and immobilization of DNA thereon is commonly employed in biosensing applications. However, with no scientific or practical guidelines to prepare a DNA sensor using these miniature gold-sputtered microelectrodes, cleaning and immobilization steps need to be systematically optimized and updated. In this work, we present efficient cleaning and modification of miniaturized gold-sputtered microelectrodes with thiolated DNA probes for DNA detection. Additional discussions on subtleties and nuances involved at each stage of pretreating and modifying gold-sputtered microelectrodes are included to present a robust, well-founded protocol. It was evident that the insights on cleaning polycrystalline gold disk electrodes with a benchmark electrode surface for DNA sensors, cannot be transferred to clean these miniature gold-sputtered microelectrodes. Therefore, a comparison between five different cleaning protocols was made to find the optimal one for gold-sputtered microelectrodes. Additionally, two principally different immobilization techniques for gold-sputtered microelectrode modification with thiolated ssDNA were compared i.e., immobilization through passive chemisorption and potential perturbation were compared in terms of thiol-specific attachment and thiol-unspecific adsorption through nitrogenous bases. The hybridization performance of these prepared electrodes was characterized by their sensitive complementary DNA capturing ability, detected by a standard alkaline phosphatase assay. Immobilization through passive chemisorption proved to be efficient in capturing the complementary target DNA with a detection limit of 0.14 nM and sensitivity of 9.38 A M−1 cm2. In general, this work presents a comprehensive understanding of cleaning, modification and performance of gold-sputtered microelectrodes with built-in gold reference and counter electrodes for both fundamental investigations and practical DNA sensing applications.

Abstract: Differential-pulse anodic stripping voltammetry is applied to determine cadmium, lead and copper in rain water acidified with nitric acid to pH 1.5, and zinc after partial neutralization to pH 4.5. Subsequently, cobalt and nickel are measured in the adsorptive mode after formation of their dimethylglyoximates. The effects of pH on the stripping peaks for Zn, Cd, Pb and Cu and of chloride on the stripping peak of copper are reported. Good agreement is found with d.p.s.v. determinations in hydrochloric acid medium and with a.a.s. measurements in most cases. Excellent accuracy is demonstrated; the average relative standard deviation per measurement appears to be between 12 and 22% for the overall analytical procedure for concentrations of 0.1550 μgl−1 of the various metals in the samples.

Abstract: The relative merits of eight procedures for preconcentrations of trace metal ions from natural water samples and synthetic solutions are evaluated. Spikes (100 μg l−1 ) of Mn, Co, Zn, Eu, Cs and Ba and the corresponding radioactive tracers were added to batches of drinking water, estuarine water, sea water, ground water, twice-distilled water and ahumic material solution. After equilibration for 25 months, the following techniques were applied: passage through columns of Dowex Al chelating resin and ofsilylated silica gel, filtration through laminate membrane filters and chelating diethylenetriamine cellulose filters, precipitation with sodium diethyldithiocarbamate and l-(2-pyridylazo)-2-naphthol, extraction with ammonium pyrrolidinedithiocarbamate, and chelation by 8-quinolinol (oxine) followed by adsorption on activated carbon. The quantitative characteristics of these techniques and the influence of the water matrix effects are discussed, as well as the applicability for x-ray fluorescence analysis.

Abstract: Differential-pulse stripping voltammetry is applied to measure zinc, cadmium, lead and copper by anodic stripping and selenium(IV) by cathodic stripping in rain water at pH 2; subsequently, at pH 9,1, manganese is measured by anodic stripping on the same portion, and cobalt and nickel are measured in the adsorptive mode after formation of their dimethylglyoximates. The instrumental parameters are optimized. The linear ranges, mutual interferences and detection limits are studied. Excellent accuracy is demonstrated; the standard deviation is around 15% at 2.550 μg l−1 levels. The method is shown to be applicable for rain water.