| 1. |
- Cagnini, A, et al.
(författare)
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Ruthenized screen-printed choline oxidase-based biosensors for measurement of anticholinesterase activity
- 1995
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Ingår i: Microchimica Acta. - : Springer Science Business Media. - 0026-3672 .- 1436-5073. ; 121:04-jan, s. 155-166
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Tidskriftsartikel (refereegranskat)abstract
- Plastic disposable choline biosensors based on ruthenized-carbon screen-printed electrodes were prepared and their use for monitoring organophosphorus pesticides and carbamates is described. The presence of 0.5% ruthenium on activated carbon mixed to form a simple graphite-based ink for the working electrode surface increased the sensitivity towards hydrogen peroxide. The choline biosensor is based on such an electrode coupled with choline oxidase immobilized by adsorption and was used to detect the inhibition effect of carbamates and organophosphorus pesticides on acetylcholinesterase. With the optimized procedure described (pH, buffer composition, incubation time, substrate concentration), concentrations of pesticides (Carbofuran) as low as 1 nM could be detected.
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| 2. |
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| 3. |
- Holmgren, Allan, et al.
(författare)
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An FT-IR study of Alizarin Red S adsorbed at the fluorapatite-water interface
- 1997
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Ingår i: Microchimica Acta. - Vienna : Springer Vienna. - 0026-3672 .- 1436-5073. ; Suppl. 14, s. 197-199
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Tidskriftsartikel (refereegranskat)abstract
- The diffuse reflectance infrared Fourier transform (DRIFT) technique was used to study sodium 1,2-dihydroxyanthraquinone-3-sulphonate (ARS) adsorbed onto the surface of fluorapatite mineral. The acidity of the water solution was varied between pH 5.4 and pH 8.4. In this pH range the infrared spectra of adsorbed ARS show that the fluorapatite surface contains precipitated calcium-ARS. The chelation of calcium strongly affects the resonance structure of the ARS molecule.
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| 4. |
- Johansson, Ursula M., et al.
(författare)
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Studies of adsorption on mineral surfaces by FT spectroscopy
- 1997
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Ingår i: Microchimica Acta. - Vienna : Springer Vienna. - 0026-3672 .- 1436-5073. ; Suppl. 14, s. 647-648
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Tidskriftsartikel (refereegranskat)abstract
- Specific surface reactions have been studied by adsorbing different type of substances on the surfaces of kaolinite and gamma-alumina. Analyses were performed by means of FT-Raman and diffuse reflectance mid-IR. The DRIFT spectra indicate isotopic exchange of hydroxyl groups on kaolinite and that it is possible to adsorb silanes at the surface. DRIFT and FT-Raman spectra indicate that the solvent map react with the gamma-alumina surface and that phosphate adsorption occurs at the surface.
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| 5. |
- Palchetti, I, et al.
(författare)
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Characterisation of screen-printed electrodes for detection of heavy metals
- 1999
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Ingår i: Microchimica Acta. - : Springer Science Business Media. - 0026-3672 .- 1436-5073. ; 131:02-jan, s. 65-73
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Tidskriftsartikel (refereegranskat)abstract
- The characterisation of disposable screen-printed electrodes for stripping analysis is described. The graphite surface of the working electrode is used as substrate for plating a thin mercury film, which allows the electrochemical preconcentration of heavy metals. Optimisation procedures and experimental results are presented. Detection limits around the ppb level were obtained for different metals [Pb(II), Cd(II), Cu(II)].
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| 6. |
- Drott, J, et al.
(författare)
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Porous silicon carrier matrices in micro enzyme reactors-influence of matrix depth
- 1999
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Ingår i: MIKROCHIMICA ACTA. - : SPRINGER-VERLAG WIEN. - 0026-3672. ; 131:1-2, s. 115-120
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The influence of the carrier matrix depth was investigated for porous silicon enzyme reactors. For the experiments, [110] oriented silicon, p-type (20-70 Ohm cm), was used. Porous silicon was generated on planar surfaces and on anisotropically pre-etched
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