1,721,116 research outputs found
A tri-enzyme electrode probe for the sequential determination of fructose and glucose in the same sample
No full textA new probe for the determination of fructose and glucose has been assembled using a platinum electrode and three enzymes co-immobilized on its surface: fructose dehydrogenase, glucose dehydrogenase and diaphorase. The mechanism of this probe is very simple: when the probe is immersed in a solution containing fructose and glucose and an electrochemical mediator, the current signal is due to the fructose. Then, by adding NAD(P)(+) a current response due to the glucose present in solution is obtained. Analytical parameters such as pH, buffer, temperature, concentration of mediator and ratio of the three enzymes co-immobilized have been optimised. Probe stability and reproducibility have been evaluated. Calibration curves for fructose and glucose have been constructed and all analytical parameters optimized. The linear range for both fructose and glucose was from 5x10(-6) to 2x10(-4) mol/L and the detection limit was 1x10(-7) mol/L. The probe has been used to determine the concentration of fructose and glucose in ten different samples of honey. The values obtained were compared with those obtained by UV-VIS spectrophotometry and the results were in good agreement
Amperometric determination of glucose, ethanol, lactate and b-hydroxybutyrate using a new purified diaphorase coimmobilized with dehydrogenase on platinum electrode
No full textAmperometric characterization of diaphorase from Bacillus stearothermophilus immobilized on different membrane surface
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Procedura di valutazione comparativa a n.1 posto da ricercatore universitario presso la facoltà di Scienze Mat. Fis. e Nat. dell'Università degli studi di Roma "Tor Vergata", per il settore scientifico-disciplinare n. CHIM 01
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Studio elettrochimico di elettrodi a pasta di nanotubi di carbonio a singola parete e confronto con elettrodi convenzionali
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