Kinetic aspects of analytical chemistry

Greinke, Ronald A.; Mark, Harry B.

doi:10.1021/ac60313a012

Cited by 9 publications

(3 citation statements)

References 183 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Τοΰτο συμβαίνει επειδή είς χαμηλάς συγκεν τρώσεις υπεροξειδίου τοϋ υδρογόνου σχηματίζεται κυρίως μονοϋπεροξείδιον, ό σχηματισμός τοϋ οποίου είναι ανεξάρτητος της συγκεντρώσεως των ιόντων υδρογόνου (έξίσ. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. Συγκρίνοντες τάς καμπύλας 1 καί 2 είς τό τμήμα της σταθεράς ταχύτητος αν τιδράσεως, παρατηροϋμεν ότι ή σχέσις των αρχικών ταχυτήτων εί ναι περίπου 2, ήτοι ώς ή σχέσις των συγκεντρώσεων υδρογόνου: (Η )ι/(Η ) 2 = 10χ10 -3 /5χ10 -3 = 2.…”

Section: μέθοδος σταθερού σήματοςunclassified

“…Ειδομεν ότι ή μή καταλυτική άντίδρασις χωρεί διά δύο ανεξαρτήτων οδών, ή δε τιμή τής σταθεράς ταχύτητος k 0 εξ αρτάται έκ τής συγκεντρώσεως των ιόντων υδρογόνου(έξισ. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17].…”

Section: προσδιορισμός των σταθερών ταχύ τητος αντιδράσεωςunclassified

“…Ό σχηματισμός των ύπεροξειδικών συμπλοκών αποδίδεται είς την άντίδρασιν τοϋ κα τιόντος V0 2 μετά τοϋ υπεροξειδίου τοϋ υδρογόνου (ή τοϋ Η 3 0 2 ) συμφώνως προς τάς κατωτέρω αντιδράσεις( 55 ' ) ε = συγκέντρωσες ελευθέρου Η 2 0 2 . *Η συνεισφορά της αντιδράσεως(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) υπό τάς εφαρμοσθείσας συνθήκας είναι πάρα πολύ μικρά. OC Nikolov καί Mihailova( 6ι ', αναφέρουν διά τήν σταθεράν kx τιμήν της τάξεως του 10~'*sec~1.…”

unclassified

See 2 more Smart Citations

Αυτοματος Καταλυτικος Μικροπροσδιορισμος Βαναδιου Και Ιριδιου

Σισκοσ¹

View full text Add to dashboard Cite

Section: μέθοδος σταθερού σήματοςunclassified

Section: προσδιορισμός των σταθερών ταχύ τητος αντιδράσεωςunclassified

unclassified

See 1 more Smart Citation

Αυτοματος Καταλυτικος Μικροπροσδιορισμος Βαναδιου Και Ιριδιου

Σισκοσ¹

View full text Add to dashboard Cite

Catalytic Kinetic Determinations: Nonenzymatic

Kawashima

Teshima

Nakano

2000

Encyclopedia of Analytical Chemistry

View full text Add to dashboard Cite

Although a catalyst does not shift the position of equilibrium but it does markedly change the reaction rate, because the catalyst lowers the activation energy of a reaction providing an alternative favorable route for the formation of the products. The reacted catalyst is regenerated and is repeatedly involved in an indicator reaction. When the rate depends on the concentration of the catalyst, it can be determined by measuring the change in the physical properties of the reactants and/or products in the indicator reaction. The change in a physical property such as absorbance, fluorescence, chemiluminescence (CL) or electrode potential of a reaction system is usually monitored with time. This methodology is called catalytic methods or kinetic–catalytic methods of analysis. Kinetic–catalytic methods of analysis based on catalyzed reactions have progressed recently and have been applied to trace analyses for various catalysts (element) because of their extremely high sensitivity, low limit of detection and selectivity. Several reactions such as redox, ligand substitution and complexation reactions have been utilized as indicator reactions for the development of kinetic–catalytic methods of trace analyses. Most of the catalysts in redox reactions are metal ions or inorganic anions having different oxidation states such as cobalt, copper, chromium, iron, manganese, vanadium, selenium, iodide, bromide and nitrite. Oxidants capable of regenerating the catalyst are hydrogen peroxide, chlorate, bromate, periodate and dissolved oxygen. Reductants include ascorbic acid, hydroxylamine, hypophosphorous acid, alkali sulfides, dithiothreitol and tin(II). Certain substances significantly increase the rate of catalyzed reactions. These substances are referred to as activators and have been defined as substances that do not catalyze the indicator reaction but enhance the catalytic effect of the catalyst. Activators provide high sensitivity and selectivity in kinetic–catalytic methods. Such improved specificity can be expected to eliminate the preliminary separation in many instances. As the measurement includes time as an experimental variable, care is needed to ensure that mixing of reagents takes place at regular time intervals to obtain highly accurate results using a manual procedure. Such disadvantages in the manual system can be overcome by using flow‐injection analysis (FIA), in which the reaction time can easily be controlled by varying the flow rate of the solutions and the length of the reaction coil. Kinetic–catalytic methods allow the determination of various elements at nanogram and picogram levels (10 −11 M) with a simple and reasonable equipment. The detection limits (DLs) of the methods are of the order of picograms per milliliter with good accuracy and precision and are almost equal to those for inductively coupled plasma mass spectrometry (ICPMS). The application of catalytic effects of metal ions in titrimetry has been recognized for a long time. This methodology is called catalytic titration and involves two consecutive reactions, i.e. titration reaction and indicator reaction. The determinable concentration is almost 10 −6 M of the metal ions.

show abstract

Catalytic effect of ReAu nanoalloy on the Te particle reaction and its application to resonance scattering spectral assay of CA125

et al. 2011

View full text Add to dashboard Cite

ReAu nanoparticles with a molar ratio of 2:8 Re and Te nanoparticles were prepared by NaBH₄ reduction. In HCl medium at 65°C, ultratrace Re, Te and ReAu bimetallic nanoparticles strongly catalyzed the slow reaction between Sn(II) and Te(VI) to form Te particles, which exhibited the strongest resonance scattering (RS) peak at 782 nm. As the amount of nanocatalyst increased, the RS intensity at 782 nm (I(782 nm) ) increased linearly, and the increase in intensity ΔI(782 nm) was linear to the ReAu, Re and Te concentrations in the ranges 0.07-9.0, 0.01-4.5 and 30-1200 nM, respectively. As a model, a ReAu immunonanoprobe catalytic Te-particle resonance scattering spectral (RSS) method was established for detection of CA125, using ReAu nanoparticle labeling CA125 antibody (CA125Ab) to obtain an immunonanoprobe (ReAuCA125Ab) for CA125. In pH 7.6 citric acid-Na₂HPO₄ buffer solution, ReAuCA125Ab aggregated nonspecifically. Upon addition of CA125, the immunonanoprobe reacted with it to form ReAuCA125Ab-CA125 dispersive immunocomplex in the solution. After the centrifugation, the supernatant containing the immunocomplex was used to catalyze the reaction of Te(VI)-Sn(II) to produce the Te particles that resulted in the I(782 nm) increasing. The ΔI(782 nm) was linear to CA125 concentration (C(CA125)) in the range 0.1-240 mU/mL. The regression equation, correlation coefficient and detection limit were ΔI(782 nm) = 1.61 C(CA125) + 1.5, 0.9978 and 0.02 mU/mL, respectively. The proposed method was applied to detect CA125 in serum samples, with satisfactory results.

show abstract

Kinetic aspects of analytical chemistry

Cited by 9 publications

References 183 publications

Αυτοματος Καταλυτικος Μικροπροσδιορισμος Βαναδιου Και Ιριδιου

Αυτοματος Καταλυτικος Μικροπροσδιορισμος Βαναδιου Και Ιριδιου

Catalytic Kinetic Determinations: Nonenzymatic

Catalytic effect of ReAu nanoalloy on the Te particle reaction and its application to resonance scattering spectral assay of CA125

Contact Info

Product

Resources

About