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61.
Viviana Scognamiglio Gianni Pezzotti Ittalo Pezzotti Juan Cano Katia Buonasera Daniela Giannini Maria Teresa Giardi 《Mikrochimica acta》2010,170(3-4):215-225
Biosensors are projected to find many applications due to their high selectivity and sensitivity, rapid reaction, economy and ease of handling in field measurements. Even though biosensors for a wide range of environmental pollutants have been extensively reported in the literature, the decision to develop a suitable biosensing system that can be approved by a regulatory perspective for environmental applications is fraught with technical issues. These issues mainly concern the biological recognition element, the physico-chemical transducer and the interfaces between the biological and the physical components, but also aspects of fluidics, electronics, and software for data processing. This article reviews methods together with a process to move biosensor technology from research laboratories to market, focusing as a case in point on challenges and possible opportunities in the development of photosynthetic-based biosensors for environmental applications. 相似文献
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A dual system of CDs was used for the first time in MEEKC with the aim of determining clemastine and its three main related impurities in both drug substances and tablets. The addition of methyl-β-cyclodextrin and heptakis(2,6-di-O-methyl)-β-cyclodextrin to the microemulsion pseudo-stationary phase was essential to increase the resolving power of the system to obtain a baseline separation among the compounds. The best microemulsion composition was identified by mixture design and the effects of the factors concentrations of CDs and voltage were investigated by a response surface study applying a Central Composite Design. In both cases, Derringer's desirability function made it possible to find the global optimum, which corresponded to the following combination: microemulsion, 89.8% 10 mM borate buffer pH 9.2, 1.5% n-heptane and 8.7% of SDS/n-butanol in 1:2 ratio; 18 mM methyl-β-cyclodextrin, 38 mM heptakis(2,6-di-O-methyl)-β-cyclodextrin, 17 kV. By applying these conditions, the separation was completed in about 5.5 min. The method was validated following International Conference on Harmonisation guidelines and was applied to a real sample of clemastine tablets. 相似文献
63.
ÜMMÜHAN OCAK HALIT KANTEKIN YAŞAR GÖK H. BASIR ŞENTÜRK 《Journal of inclusion phenomena and macrocyclic chemistry》2006,55(1-2):87-91
The selective liquid–liquid extraction of various transition metal cations from the aqueous phase to the organic phase was carried out using a 14-membered N2O2S2-macrobicycle. Metal picrates such as Pb2+, Co2+, Zn2+, Ni2+,Cu2+ and Cd2+ were used in this extraction studies. It was found that the ligand showed moderate selectivity towards Pb2+ only among the other metals. The extraction constant (log K
ex) was determined to be 13.8 for Pb2+ complex. 相似文献
64.
A rapid and simple method based on capillary electrophoresis was developed for the quality control of nutraceuticals containing resveratrol. Setting the UV detector at 280nm, the optimisation involved the separation of 11 effervescent tablet components, including the active compounds vitamin C, vitamin B(2), flavanones and hydroxycinnamic acids. Flufenamic acid was employed as internal standard. The effects of background electrolyte concentration, acetonitrile percentage and voltage were investigated by means of response surface methodology, considering as responses the critical resolution values and analysis time. The optimum conditions were found by Derringer desirability function. The background electrolyte consisted of 23mM borate buffer, adjusted to pH 10.0 with 1M sodium hydroxide, containing 7% (v/v) acetonitrile. Temperature and voltage were set at 25 degrees C and 26kV, respectively. Applying these conditions, the analysis time was below 7min. The performances of the method were tested in terms of selectivity, robustness, linearity and range, accuracy and precision and system suitability, following ICH guidelines. 相似文献
65.
Pieraccini G Furlanetto S Orlandini S Bartolucci G Giannini I Pinzauti S Moneti G 《Journal of chromatography. A》2008,1180(1-2):138-150
The qualitative and quantitative determination of components of mainstream and sidestream smoke has been performed by solid-phase microextraction-gas chromatography-mass spectrometry. Several brands and types of cigarettes sold in Italy were considered: normal, mild, light, extra light, some with filter and some without. Extraction of the analytes was performed by means of solid-phase microextraction (SPME) and the optimisation of the extraction procedure was performed by experimental design, taking into consideration type of fiber polymer, exposure temperature and time. Sixty-seven components of mainstream and sidestream smoke were identified. The quantified compounds (by means of deuterium-labelled isotopologues) were benzene, toluene, p-xylene, m-xylene, pyridine, o-xylene, limonene, naphthalene, phenol and nicotine. Finally, a comparison between the chemical profile of smoke from the different cigarettes was made. 相似文献
66.
E. Albizzati U. Giannini G. Balbontin I. Camurati J. C. Chadwick T. Dall'occo Y. Dubitsky M. Galimberti G. Morini A. Maldotti 《Journal of polymer science. Part A, Polymer chemistry》1997,35(13):2645-2652
The behavior in propylene polymerization of divalent titanium compounds of type [η6-areneTiAl2Cl8], both as such and supported on activated MgCl2, has been studied and compared to that of the simple catalyst MgCl2/TiCl4. Triethylaluminium was used as cocatalyst. The Ti–arene complexes were active both in the presence and in the absence of hydrogen, in contrast to earlier reports that divalent titanium species are active for ethylene but not for propylene polymerization. 13C-NMR analysis of low molecular weight polymer fractions indicated that the hydrogen activation effect observed for the MgCl2-supported catalysts should be ascribed to reactivation of 2,1-inserted (“dormant”) sites via chain transfer, rather than to (re)generation of active trivalent Ti via oxidative addition of hydrogen to divalent species. Decay in activity during polymerization was observed with both catalysts, indicating that for MgCl2/TiCl4 catalysts decay is not necessarily due to overreduction of Ti to the divalent state during polymerization. In ethylene polymerization both catalysts exhibited an acceleration rather than a decay profile. It is suggested that the observed decay in activity during propylene polymerization may be due to the formation of clustered species that are too hindered for propylene but that allow ethylene polymerization. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 2645–2652, 1997 相似文献
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Ahlen S Ambrosio M Antolini R Auriemma G Baker R Baldini A Barbarino GC Barish BC Battistoni G Bellotti R Bemporad C Bernardini P Bilokon H Bisi V Bloise C Bussino S Cafagna F Calicchio M Campana P Campana D Carboni M Cecchini S Cei F Chiarella V Chiera C Cobis A Cormack R Corona A Coutu S DeCataldo G Dekhissi H DeMarzo C De Vincenzi M Di Credico A Diehl E Erriquez O Favuzzi C Ficenec D Forti C Foti L Fusco P Giacomelli G Giannini G Giglietto N Giubellino P Grassi M Green P Grillo A Guarino F 《Physical review letters》1992,69(13):1860-1863
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