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1.
Application of matrix solid-phase dispersion in the analysis of priority polycyclic aromatic hydrocarbons in fish samples 总被引:1,自引:0,他引:1
The performance of matrix solid-phase dispersion (MSPD) for the extraction of polycyclic aromatic hydrocarbons (PAHs) in fish tissue is described. The suitability of different solid supports was tested as well as the influence on the extraction efficiency of the natural fat content in samples. Under optimal conditions 0.6-0.8 g of tissue sample, are dispersed with 2 g of octadecylsiloxane (C18) and 0.5 g of anhydrous sodium sulphate and transferred to the top of a polyethylene solid-phase extraction cartridge which already contains 2 g of florisil and 1 g of C18. Cartridges were eluted with acetonitrile. The analysis of the extracts was carried out by high-performance liquid chromatography (HPLC) coupled with fluorescence detection. The proposed method provides detection limits between 0.04 and 0.32 ng/g for the different considered PAHs, below the maximum levels established by the some regulatory bodies for the six PAHs after recent oil spill episodes and European Union regulations. Recoveries over 80% were obtained for all compounds. Accuracy validation was carried out using the US National Institute of Standards and Technology (NIST) SRM 2977 reference material. 相似文献
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Morelos A Albuquerque IF Bondar NF Carrigan RA Chen D Cooper PS Lisheng D Denisov AS Dobrovolsky AV Dubbs T Endler AM Escobar CO Foucher M Golovtsov VL Gottschalk H Gouffon P Grachev VT Khanzadeev AV Kubantsev MA Kuropatkin NP Lach J Lang Pengfei Li Chengze Li Yunshan Luksys M Mahon JR McCliment E Newsom C Pommot Maia MC Samsonov VM Schegelsky VA Shi Huanzhang Smith VJ Tang Fukun Terentyev NK Timm S Tkatch II Uvarov LN Vorobyov AA Yan Jie Zhao Wenheng Shuchen Z Zhong Yuanyuan 《Physical review letters》1993,71(21):3417-3420
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Morelos A Albuquerque IF Bondar NF Carrigan RA Chen D Cooper PS Dai Lisheng Denisov AS Dobrovolsky AV Dubbs T Endler AM Escobar CO Foucher M Golovtsov VL Gottschalk H Gouffon P Grachev VT Khanzadeev AV Kubantsev MA Kuropatkin NP Lach J Lang Pengfei Li Chengze Li Yunshan Luksys M Mahon JR McCliment E Newsom C Pommot Maia MC Samsonov VM Schegelsky VA Shi Huanzhang Smith VJ Tang Fukun Terentyev NK Timm S Tkatch II Uvarov LN Vorobyov AA Yan Jie Zhao Wenheng Zheng Shuchen Zhong Yuanyuan 《Physical review letters》1993,71(14):2172-2175
4.
Teixeira-Neto É Leite CA Cardoso AH Medeiros da Silva MC Braga M Galembeck F 《Journal of colloid and interface science》2000,231(1):182-189
Poly(styrene-co-acrylamide) (PS-AAM) latex was prepared, fractionated by sedimentation under gravity, and characterized by PCS, infrared spectra, secondary and backscattered electron imaging in the scanning electron microscope, and electron spectroscopy imaging in an analytical transmission electron microscope. Three latex fractions were obtained. The lower fraction was opalescent and its particles were the more uniform, concerning size, chemical composition, and topochemical features. This lower fraction was still further fractionated by zonal centrifugation in a density gradient, yielding two fractions with similar macrocrystal-forming abilities but different sizes and chemical compositions. These results confirm those previously obtained for the PS-HEMA latex. Copyright 2000 Academic Press. 相似文献
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García-Río L Hervés P Mejuto JC Pérez-Juste J Rodríguez-Dafonte P 《Journal of colloid and interface science》2000,225(2):259-264
We carried out an investigation on the influence of several alkylamines, frequently present in reactions carried out in microemulsions, on the properties of the water/AOT/isooctane system. The presence of alkylamines has an important effect on the electrical percolation phenomena. This effect of amines on the electrical percolation of microemulsions of AOT/isooctane/water can be explained by taking into account the ability of these substrates to associate with the AOT film in the microemulsion, the basicity of the amine, and the different solubility of the amine in the three pseudophases of the system. Copyright 2000 Academic Press. 相似文献
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Dasilva-Carbalhal J García-Río L Gómez-Díaz D Mejuto JC Pérez-Lorenzo M 《Journal of colloid and interface science》2005,292(2):591-594
A study was carried out on the influence of different polyethylene glycol dimethyl ethers (glymes) on the conductance percolation of AOT/isooctane/water microemulsions. The glymes used were chosen on the basis of this chain length (the number of polymeric units). In all cases we observed a decrease in the percolation threshold on increasing the amount of a glyme added to the microemulsion. We observed a correlation between the effect exerted by the glyme and its chain length, which shows the importance of including them in the interface for the percolative phenomenon. Such inclusion modifies the properties of the AOT film, facilitating the exchange of matter between droplets. 相似文献
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Gonzalo Astray Juan F. Gálvez Juan C. Mejuto Oscar A. Moldes Iago Montoya 《Journal of computational chemistry》2013,34(5):355-359
In this article, an artificial neural network to predict the flash point of 95 esters was implemented. Four variables were used for its development. A neural network with 4‐5‐8‐5‐1 topology was encountered to gain the best agreement of the experimental results with those predicted (square correlation coefficient (R2) and root mean square error were 0.99 and 5.46 K for the training phase and 0.96 and 13.02 K for the testing set). © 2012 Wiley Periodicals, Inc. 相似文献
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L. García-Río J.C. Mejuto M. Nieto J. Pérez-Juste M. Pérez-Lorenzo P. Rodríguez-Dafonte 《Supramolecular chemistry》2013,25(8):649-653
The influence of β-CD concentration on the acid hydrolysis of N-methyl-N-nitroso-p-toluenesulfonamide (MNTS) has been studied in the presence and absence of different alcohol concentrations. The rate of the denitrosation reaction in bulk water decrease as the β-CD concentration increases due to MNTS complexation in the CD cavity and the reaction taking place exclusively outside the cyclodextrin. Changes in this inhibition due to the presence of β-CD allow us to obtain the binding constants of different alcohols to the cyclodextrin. These binding constants are in very good agreement with those determined in the bibliography by other methods. 相似文献