36 research outputs found
Spatial, geomorphological, and seasonal variability of CDOM in estuaries of the Florida Coastal Everglades
Inorganic Mass Spectrometry
To establish a method for sensitive, accurate, and precise determination of Se in real samples, isotope dilution analysis using high-power nitrogen microwave-induced plasma mass spectrometry (N 2 MIP-IDMS) was conducted. In this study, freeze-dried human blood serum (Standard Reference Material, NIES No. 4) provided by NIES (National Institute for Environmental Studies) was used as a real sample. The measured isotopes of Se were 78 Se and 80 Se which are the major isotopes of Se. The appropriate amount of a Se spike solution was theoretically calculated by using an error multiplication factor (F) and was confirmed experimentally for the isotope dilution analysis. The mass discrimination effect was corrected for by using a standard Se solution for the measurement of Se isotope ratios in the spiked sample. However, the sensitivity for the detection of Se was not so good and the precision of the determination was not improved (2-3%) by N 2 MIP-IDMS with use of the conventional nebulizer. Therefore, a hydride generation system was connected to N 2 MIP-IDMS as a sample introduction system (HG-N 2 MIP-IDMS) in order to establish a more sensitive detection and a more precise determination of Se. A detection limit (3Ï) of 10 pg mL -1 could be achieved, and the RSD was less than 1% at the concentration level of 5.0-10.0 ng mL -1 by HG-N 2 MIP-IDMS. The analytical results were found to be in a good agreement with those obtained by the standard addition method using conventional Ar ICPMS. It is well-known that Se is an essential element for all mammals. Se deficiency leads to deficiency syndromes, for example, Keshan disease, which is known for cardiac insufficiency that occurred in children and pregnant women in China. Problems also occur if the concentration of Se is too high; for example, gastroenteric disorders, dermatitis, and neurotic disorders are caused by excessive intake of Se. Moreover, it is well-known that the range of permissive intake amounts of Se is very narrow for human beings. Therefore, it is restricted as a toxic element in environmental standards. There are several sources of environmental Se pollution: the processes of Se refinement and the production processes of Se-containing products. For these reasons, the accurate and precise determination of trace levels of Se in environmental and biological samples is required, and studies of Se determination have been reported by several groups. [1][2][3][4][5][6][7][8][9][10][11] Because Ar ICPMS can measure multiple elements at a concentration range from ng mL -1 to fg mL -1 , it has widespread use in the determination of trace elements in various samples. 12-25 However
Harmful Elements in Estuarine and Coastal Systems
Estuaries and coastal zones are dynamic transitional systems which provide many economic and ecological benefits to humans, but also are an ideal habitat for other organisms as well. These areas are becoming contaminated by various anthropogenic activities due to a quick economic growth and urbanization. This chapter explores the sources, chemical speciation, sediment accumulation and removal mechanisms of the harmful elements in estuarine and coastal seawaters. It also describes the effects of toxic elements on aquatic flora and fauna. Finally, the toxic element pollution of the Venice Lagoon, a transitional water body located in the northeastern part of Italy, is discussed as a case study, by presenting the procedures adopted to measure the extent of the pollution, the impacts on organisms and the restoration activities
Relevancy of speciation analysis for geographical origin discrimination of red wines
International audienceWine traceability has become of primary importance for consumers as well as for producers. Indeed, because of its high market price, it's a product highly subject to fraud. Traceability analysis are, among others, performed by trace element analysis. Indeed, their content may change depending on the soils on which the vine has grown and also as a function of the agricultural practices. But in addition, these different origins may also impact these trace elements speciation. Therefore, the objective of our work was to check if the speciation analysis could be more discriminant than the single total element content for geographical discrimination purpose. In a first step, the development and the validation of the speciation methods of different elements (As, Se) in red wine will be described. Then, the application of these methods to the analysis of red wines from different geographical origin will be presented. Finally, the statistical treatment of these data will allow to the conclusion about the relevancy of using speciation analysis to discriminate the geographical origin of red wines
Organotins in sediments and biological tissues from Greek coastal areas: Preliminary results
cited By 24International audienceno abstrac
Breast cancer (Ductal Carcinoma) detection and classification software using fuzzy pattern recognition
The research deals on the detection and classification of Breast Carcinoma particularly Ductal Carcinoma. The study takes on the characteristics and definitions of Ductal Carcinoma by having a digital image from stained breast tissue samples, as seen in the microscope, analyzed and evaluated using Image Processing (first module) and Fuzzy Pattern Recognition (second module). The first module analyzes the Terminal Duct Lobular Unit (TDLU) by implementing a number of processing techniques such as Nuclei Extraction, Filtering and Feature Extraction to name a few. The second module uses Fuzzy Membership Functions to evaluate the degree and level at which the image is an Invasive Carcinoma (malignant) or Noninvasive (benign) and if invasive, would it be an Invasive Ductal Carcinoma NST (no specific type) or of a different type. The overall accuracy of the study is 95%
Monitoring bacterial communities adaptation to mercury contamination in estuarine sediments maintained in slurries
cited By 4International audienceAdour sediments were incubated in slurries and polluted with inorganic mercury (HgCl2) to follow the adaptation of microbial communities to mercury. Mercury methylation was observed only in slurries maintained under anoxic conditions. Temporal variation of microbial community was identified using molecular approaches. The T-RFLP method based on the 16S ribosomal RNA encoding gene analysis demonstrated that microbial community structure was strongly dependent of mercury methylation potential. The analysis based on the functional mer genes involved in mercury resistance mechanisms revealed the presence of well adapted bacterial populations in Adour sediments. Furthermore significant modifications of the distribution of mer genes during incubation time were observed indicating that mercury addition influenced also the resistant populations
Pro-metrofood project: Involvement of the French node in setting up a novel European research infrastructure in food and nutrition
International audienc