European Space Agency (ESA), the World over Scientific organization, North Atlantic Treaty Organization (NATO), National Aeronautics and Space Administration (NASA) and WOrld Meteorological ...Organization are deeply concerned with the dis-balances caused to a significant extent due to human interference in the natural make-up of earth's ecosystem. In particular, the ozone layer depletion (OLD) over the South Pole is already a serious hazard. The principal long-term effect of OLD appears to be an increase in the UV radiation reaching the earth. In our earlier findings on OLD have been reported and the effects could be observed using the data obtained from a ground based instrument known as Dobson Spectrophotometer installed at GC Quetta Pakistan. We have also computed UV flux reaching Arabian Sea due to the OLD. Then we have presented correlation structures of the population dynamics of marine organisms (fish yield and others) with the intensity of UV flux. The results are compared with the data acquired from Total Ozone Mapping Spectrometer (TOMS) Nimbus -7.
The aim of the investigation was to elucidate the extent and directions of possible alterations in the process of biosynthesis of surface lipid (SL) molecules in the presence of some toxicants and ...realize if some SL molecules could be stress markers. The emphasis is made on some water plants, representatives of helophytes. Some plants (contaminant exposed) grown on sewage ponds of Dniepropetrovs'k varnish-dye plant with complex contamination were investigated. Spectral (Fourier transform infrared, FTIR), thermogravimetric (TG) and gas chromatography — mass spectrometry (GC-MS) data were considered. FTIR-spectra of SL of contaminant non-exposed and contaminant exposed plant samples had some differences concerning absorbtion of some characteristic bands; TG and evolutional profiles of water, also carbon dioxide and carbon monoxide evolution had some differences in control and contaminant exposed plants. The results confirm their different molecular-dynamic characteristics, dependent from content and associative abilities. Changes in composition of SL took place under influence of contaminants. The content of fatty acids and hydrocarbons changed in SL of contaminant exposed plants in comparison with control.
The content that appears in this chapter has been largely adapted from the following publications and manuscript in press: Zhao J, Pinchuk AO, McMahon JM, Li S, Ausman LK, Atkinson AL, Schatz GC ...(2008) Methods for describing the electromagnetic properties of silver and gold nanoparticles. Acc Chem Res 41:1710–1720. doi:10.1021/ar800028jAtkinson AL, McMahon JM, Schatz GC (2009) FDTD studies of metallic nanoparticle systems. In: Self organization of molecular systems, from molecules and clusters to nanotubes and proteins. NATO science for peace and security series A: chemistry and biology. Springer, Netherlands. doi:10.1007/978-90-481-2590-6
In this study the gas phase photocatalytic oxidation of naphthalene in the presence of TiO2-based photocatalysts prepared by chemical vapor deposition (CVD) and the sol-gel method is examined. As ...precursors for the photocatalyst preparation TiCl4 was used for chemical vapor deposition (CVD), while for the sol-gel technique the precursor was titanium tetra-isopropoxide. The level of naphthalene degradation was examined with FTIR spectroscopy; the identification of the products obtained was performed by GC-MS measurements. The kinetics of the photooxidation reaction of naphthalene in excess of oxygen was investigated. It was found that the kinetics of naphthalene oxidation follow a first-order law; the rate constants were determined by means of mathematical modeling. Also, it was found that the rate limiting steps for naphthalene oxidation are diffusion of the components on the catalyst surface and transport through the films of the photocatalyst particles. The photocatalytic activity of TiO2-based photocatalysts prepared by CVD as a gas phase method and the sol-gel technique as a liquid method are compared. The photocatalysts showed an excellent efficiency for naphthalene degradation in the presence of oxygen; a complete mineralization of the aromatic toxic compound to CO2 and water was achieved.
Nitric monooxide (NO) and nitric oxides (NOx) are the dangerous air pollutants possessing high nitrosative and genotoxic potential with adverse health effects. Environmental NO is related to ...nitrosative stress development in human body. Overproduction of NO has been implicated as a pathological factor in several forms of chronic human diseases, including cancer. The aim of this study was to evaluate exposure and risk associated with exogenic NOx impact on the growth of model tumor Guerin's carcinoma (GC), xanthine oxidoreductase (XOR) activity, levels of mobile lipid domens (MLD), functional activity of peritoneal macrophages (PM) and lipid peroxidation (LPO) in tumor tissue. Exogenous NOx inhalation leads to nitrosative stress development and toxic effect on cells of immune system in vivo. Tumor growth was accompanied by activation of PM. The prolonged inhalation of exogenous NOx caused hyperactivation of PM (4.9-fold), increased MLD formation and total XOR activity (1.6-fold), and accompanied by accelerated tumor growth. In paralel observed sharp decrease (2.4-fold) of xanthine oxidase (XO) activity and LPO level (3.5-fold). The ratio of XOR isoforms increased by 18-fold mainly due to inactivation of xanthine dehydrogenase form (XDH). Reverse correlation was observed between the considerable increase of XOR activity in tumors and decline of GC nodes sizes. The high activity of enzyme in tumor tissues was accompanied by a 3.8-fold decrease in a final size of GC nodes as compared to tumors with lower activity of XOR.
Methods to analyze chemical warfare agents (CW-agents) and their decomposition products in environmental samples were developed over the last decades. In contrast herewith, procedures for analysis in ...biological samples have only recently been developed. Retrospective detection of exposure to CW-agents is useful for various applications. It can be envisaged that rapid diagnosis will play a pivotal role in the management of a terrorist attack with CW-agents. In the same context, confirmation of non-exposure of worried citizens is of utmost importance to suppress unrest in the society at large. Also, such methods can be used for forensic analyses in case of suspected terrorist activities (“chemical fingerprints”). These methods will also be valuable in case of a military conflict, e.g., to establish firmly to which chemicals casualties have been exposed to, as a starting point for adequate medical treatment. Finally, the procedures can be used for health surveillance of workers in destruction facilities of CW-agents. This presentation will deal with specific methods currently available for diagnosis of exposure to the most common CW-agents, i.e., nerve agents and mustard agents. Although the presentation will focus on GC/MS and LC/MS analyses of the long-lived protein adducts of these agents, some attention will be paid to metabolites in urine and immuno-chemical detection of DNA- and protein adducts. The utility of the presented methods will be exemplified on the basis of exposure incidents.
In this study honey collected from local markets or made by private peasants from eighteen regions of Romania during years 2002-2004 were analyzed for organochlorine pesticides (OCPs). An analytical ...procedure based on liquid-liquid extraction with n-hexane followed by gas chromatography with electron capture detection (GC-ECD) has been developed. For clean-up and preconcentration purposes was used a usual sorbent material (florisil). Limits of detection were from 0.02 and 0.05 μg /Kg. The pesticide endrin was the most frequently detected in 61% of the samples, followed by dieldrin in 16% of the samples. DDT and their metabolites were detected in 11% of the samples. Results indicate that honey consumers should not be concerned about the amounts of organic pollutants found in Romanian honey.
The interaction of chemical dispersants and suspended sediments with crude oil influences the fate and transport of oil spills in coastal waters. A wave tank study was conducted to investigate the ...effects of chemical dispersants and mineral fines on dispersion of oil, formation of oil-mineral-aggregates (OMAs), and microbial activities in natural seawater. Results of ultraviolet fluoremetry (UVF) and gas chromatography-flame ionized detector (GC-FID) analysis indicate that both dispersants and mineral fines, alone and in combination, stimulate the dispersion of oil slick from surface to water column. A laser in-situ scattering and transsiometer (LISST-100X) measurement shows that the presence of mineral fines increased the total concentration of the suspended particles from 4 to 10 μL/L, whereas the presence of dispersants decreased the particle size (mass mean diameter) from 50–70 to 20 μm. Enumeration with epifluorescent microscope shows that the presence of either dispersants or mineral fines significantly increased the number of particles in water.
The aim of this study was to determine the PBDE contents in selected food products available on the Polish market: butter, eggs, chocolate, pork fat, beef fat, and three kinds of fish: carp, salmon ...and cod. Therefore, a two-stage (for fish) and three-stage (for all the other food products) methods of sample cleanup was developed with the use of the GC-MS technique, using semipermeable membranes (SPM) in one of the stages. In all of the samples six dominating PBDE congeners: BDE-28, BDE-47, BDE-99, BDE-100, BDE-153, and BDE-154 were determinated. PBDE contents in the Polish butter ranged from 55 to 174 pg/g of fat. The results for the fish samples (salmon and cod) were shown to be highly variable. The analysed salmon samples contained for example 377–5,340 pg/g of the wet muscle tissue (1,850–26,700 pg/g of fat, respectively).
Due to the high lipophilicity of dioxins are related compounds, more than 90% of the human exposure to dioxins is due to consumption of lipid-rich food such as meat; milk and dairies, as well as fish ...and derived products. The measurement of these trace level analytes requires a complex and tedious procedure including sample extraction, sample clean-up, and physico-chemical analysis after Chromatographic separation. The determination of dioxins and related compounds requires a method that provides extremely high sensitivity and selectivity. High-resolution gas chromatography (HRGC) in combination with high-resolution mass spectrometry (HRMS) is the ‘gold’ standard method. In selected ion monitoring (SIM) mode, HRGC-HRMS (10,000 resolution) can achieve detection limit at the femtogram (10-15 g) level for most of the dioxin congeners. This paper explains the specificities and the pitfalls that could be met by analysts during the analytical development of this particular technique. Sample preparation, cleanup, selection of GC columns, specific aspects of double focusing sector instruments in SIM mode, high-resolution in mass, quantification by isotope dilution technique, quality assurance and quality control requirements and future perspectives are discussed and illustrated. A brief discussion of the bio-analytical approach is also provided to complete the analytical picture. Levels and trends for dioxins in food are discussed in the final part of the manuscript in the context of European regulation.
