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Fabio D’Agostino Elvira Oliveri Emanuela Bagnato Francesca Falco Salvatore Mazzola Mario Sprovieri 《Analytica chimica acta》2014
The aim of this work was to develop a new method to determine the mercury (Hg) concentrations in phosphate rock using a dedicated analytical instrument (the DMA80 Tricell by Milestone) that employs an integrated sequence of thermal decomposition followed by catalyst conversion, amalgamation and atomic absorption spectrophotometry. However, this instrument underestimates Hg concentrations when phosphorite and apatite rocks are investigated with a classic thermal decomposition treatment that complies with US EPA method 7473. 相似文献
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Francesca Benedini Giorgio Bertolini Francesco Ferrario Angelo Motti Alberto Sala Flavio Somenzi 《Journal of heterocyclic chemistry》1995,32(1):103-107
The preparation and the physico-chemical characterization of 2H-pyrido[2,3-e]-1,3-oxazine-2,4(3H)-diones, 2H-pyrido[4,3-e]-1,3-oxazine-2,4(3H)-diones, 2H-pyrido[4,3-e]-1,3-oxazin-4(3H)-ones, 2H-thieno[2,3-e]-1,3-oxazin-4(3H)-ones and 2H-thieno[3,4-e]-1,3-oxazine-2,4(3H)-diones are reported. 相似文献
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Eslava S Baklanov MR Kirschhock CE Iacopi F Aldea S Maex K Martens JA 《Langmuir : the ACS journal of surfaces and colloids》2007,23(26):12811-12816
Ellipsometric porosimetry was used to determine the adsorption isotherms of toluene, methanol, and water on b-oriented Silicalite-1 coatings with a thickness of less than ca. 250 nm and to obtain adsorption kinetics. The adsorption isotherms are of sufficient quality to reveal several aspects of the pore structure such as the adsorbate capacity and the adsorbate/framework affinity. The use of a combination of different molecular probes in ellipsometric porosimetry to elucidate the molecular accessibility of Silicalite-1 pores is demonstrated. It is shown that ellipsometric porosimetry is an appropriate technique for probing the influence of aging of the Silicalite-1 coating and of planarization polishing on the porosity, pore accessibility, and adsorbate/framework affinity. 相似文献
65.
Alberto Girlando Cristina Sissa Francesca Terenziani Anna Painelli Anna Chwialkowska Geoffrey J Ashwell 《Chemphyschem》2007,8(15):2195-2201
We report visible, Raman, and infrared spectra of self-assembled monolayers (SAMs) formed by the donor-(pi-bridge)-acceptor chromophore, Z-beta-[N-(omega-acetylthioalkyl)-4-quinolinium]-alpha-cyano-4-styryldicyanomethanide (CH3CO-S-CnH2n-Q3CNQ where n=8, 10), on gold-coated substrates. The data are compared with the spectra collected for the same compound in solution and in the solid state, and with those obtained for a Langmuir-Blodgett (LB) monolayer of C16H33-Q3CNQ deposited on gold. Spectral analysis confirms that in solution, in the solid state and in the LB film the chromophore has a zwitterionic (D+-pi-A-) ground state. At variance with this well-known result, our data show that in SAMs deposited on gold the chromophore has a more neutral, quinoid ground state. We relate this difference to the different packing of the molecules in the two different films: in SAMs in fact the chromophores stand almost vertical with respect to the substrate, whereas in LB films they make an angle of about 45 degrees. The Q3CNQ molecule is a well-known molecular rectifier, and for SAMs we were able to check the direction of electron flow at forward bias on the same samples that have been characterized spectroscopically, shedding light on the rectification mechanism. 相似文献
66.
Graham SF Ruiz-Aracama A Lommen A Cannizzo FT Biolatti B Elliott CT Mooney MH 《Analytical and bioanalytical chemistry》2012,403(2):573-582
Detection of growth-promoter use in animal production systems still proves to be an analytical challenge despite years of
activity in the field. This study reports on the capability of NMR metabolomic profiling techniques to discriminate between
plasma samples obtained from cattle treated with different groups of growth-promoting hormones (dexamethasone, prednisolone,
oestradiol) based on recorded metabolite profiles. Two methods of NMR analysis were investigated—a Carr–Purcell–Meiboom–Gill
(CPMG)-pulse sequence technique and a conventional 1H NMR method using pre-extracted plasma. Using the CPMG method, 17 distinct metabolites could be identified from the spectra.
1H NMR analysis of extracted plasma facilitated identification of 23 metabolites—six more than the alternative method and all
within the aromatic region. Multivariate statistical analysis of acquired data from both forms of NMR analysis separated the
plasma metabolite profiles into distinct sample cluster sets representative of the different animal study groups. Samples
from both sets of corticosteroid-treated animals—dexamethasone and prednisolone—were found to be clustered relatively closely
and had similar alterations to identified metabolite panels. Distinctive metabolite profiles, different from those observed
within plasma from corticosteroid-treated animal plasma, were observed in oestradiol-treated animals and samples from these
animals formed a cluster spatially isolated from control animal plasma samples. These findings suggest the potential use of
NMR methodologies of plasma metabolite analysis as a high-throughput screening technique to aid detection of growth promoter
use. 相似文献
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