Chemiluminescence (CL) emission generated during oxidation of pyrogallol and its application in analytical chemistry. I. Effect of oxidant compound
Φόρτωση...
Ημερομηνία
Συγγραφείς
Evmiridis, N. P.
Thanasoulias, N. K.
Vlessidis, A. G.
Τίτλος Εφημερίδας
Περιοδικό ISSN
Τίτλος τόμου
Εκδότης
Elsevier
Περίληψη
Τύπος
Είδος δημοσίευσης σε συνέδριο
Είδος περιοδικού
peer reviewed
Είδος εκπαιδευτικού υλικού
Όνομα συνεδρίου
Όνομα περιοδικού
Talanta
Όνομα βιβλίου
Σειρά βιβλίου
Έκδοση βιβλίου
Συμπληρωματικός/δευτερεύων τίτλος
Περιγραφή
An investigation of chemiluminescence (CL)-emission generated by the oxidation of pyrogallol using various inorganic oxidant compounds is reported in this F.I.A.-merging zone application. The oxidant compounds that showed measurable CL-emission were permanganate, periodate, hypochlorite anions, cerium(IV) and hydrogen peroxide. The different oxidant compounds showed CL-emissions at different pH-ranges. The CL-emission was limited by the inner filter effect and this was more intense for oxidants of selective oxidation. Kinetic effects were also found in the case of oxidation by permanganate. Plots of CL-emission against pH give evidence of speciation and or deactivation mechanism effects. The analytical parameters for the determination of the oxidants are given. Sensitivities of 895 600, 19 500, 33 723, 10 680 and 56 703 mV M-1 were found for the determination of permanganate, cerium(IV), periodate, hypochlorite and hydrogen peroxide, respectively. The calibration curves of the oxidant determination were generally S-shaped; the S-shaped calibration curve of periodate was closer to a straight line relationship while that of hypochlorite was almost a straight line; detection limits in the range of 10(-4) M oxidant concentration were found for nearly all oxidants. The analytical parameters for determination of pyrogallol by the CL-emission generated through oxidation by the different oxidants at optimum conditions were 1.16 x 10(6) mV M-1 for permanganate; 0.086 x 10(6) mV M-1 for cerium(IV); 0.91 x 10(6) mV M-1 for periodate; 0.012 x 10(6) mV M-1 for hypochlorite; and 0.25 x 10(6) mV M-1 for hydrogen peroxide. The detection limit was 1.0 x 10(-4) M. The nearly straight-line relationship (initial part of the plot) for CL-emission with oxidant concentration gives an indication that the CL-reaction of pyrogallol oxidation by hypochlorite proceeds through a process that involves energy transfer while the pronounced S-shaped curve produced by permanganate gives the indication that the reaction proceeds through a process that does not involve energy transfer according to the mathematical model of CL-emission that controls the F.I.A.-merging zone technique of the flow apparatus used in this work. The sequence of completeness of the oxidation process by each oxidant was MnO4- > H2O2 > IO4- > OCl-; the stoichiometric quantity of the oxidant per pyrogallol molecule for the rapid part of the overall oxidation by each different oxidant was attempted; this is an index-value of the oxidation state of the fluorescent excited molecule. Finally, the impact of the above findings for further analytical applications is discussed. (C) 1998 Elsevier Science B.V. All rights reserved.
Περιγραφή
Λέξεις-κλειδιά
chemiluminescence (cl)-emission, pyrogallol oxidation, oxidants, ph-selectivity, prospects for analytical applications, flow-injection analysis, calibration curve, periodate, luminescence
Θεματική κατηγορία
Παραπομπή
Σύνδεσμος
<Go to ISI>://000072786800022
http://ac.els-cdn.com/S0039914097002725/1-s2.0-S0039914097002725-main.pdf?_tid=7b6c0f48-356a-11e3-bb42-00000aab0f02&acdnat=1381821900_4cdf2814e2e3f04d484f295e4e5262f1
http://ac.els-cdn.com/S0039914097002725/1-s2.0-S0039914097002725-main.pdf?_tid=7b6c0f48-356a-11e3-bb42-00000aab0f02&acdnat=1381821900_4cdf2814e2e3f04d484f295e4e5262f1
Γλώσσα
en
Εκδίδον τμήμα/τομέας
Όνομα επιβλέποντος
Εξεταστική επιτροπή
Γενική Περιγραφή / Σχόλια
Ίδρυμα και Σχολή/Τμήμα του υποβάλλοντος
Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Χημείας