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Chemiluminescence hydrogen peroxide determination

Bis(2,4,6-tiichlorophenyl) oxalate (TCPO) chemiluminescence, 648, 1189, 1190, 1222, 1225, 1226, 1258, 1268-9 hydrogen peroxide determination, 637-8 hydroperoxide determination, 682 Bis(tiifluoromethyl) peroxide, molecular stmcture, 713... [Pg.1446]

Tetramethylammonium ozonide, 736 Tetramethyl-l,2-dioxetane (TMD) chemical titration, 1224 chemiluminescence, 1221, 1234 quantum yield standard, 1224, 1226 N,N, N, A -Tetramethyl-p-phenylenediamine hydrogen peroxide determination, 735, 631, 633... [Pg.1492]

The first detailed investigation of the reaction kinetics was reported in 1984 (68). The reaction of bis(pentachlorophenyl) oxalate [1173-75-7] (PCPO) and hydrogen peroxide cataly2ed by sodium saUcylate in chlorobenzene produced chemiluminescence from diphenylamine (DPA) as a simple time—intensity profile from which a chemiluminescence decay rate constant could be determined. These studies demonstrated a first-order dependence for both PCPO and hydrogen peroxide and a zero-order dependence on the fluorescer in accord with an earher study (9). Furthermore, the chemiluminescence quantum efficiencies Qc) are dependent on the ease of oxidation of the fluorescer, an unstable, short-hved intermediate (r = 0.5 /is) serves as the chemical activator, and such a short-hved species "is not consistent with attempts to identify a relatively stable dioxetane as the intermediate" (68). [Pg.266]

Divalent copper, cobalt, nickel, and vanadyl ions promote chemiluminescence from the luminol—hydrogen peroxide reaction, which can be used to determine these metals to concentrations of 1—10 ppb (272,273). The light intensity is generally linear with metal concentration of 10 to 10 M range (272). Manganese(II) can also be determined when an amine is added to increase its reduction potential by stabili2ing Mn (ITT) (272). Since all of these ions are active, ion exchange must be used for deterrnination of a particular metal in mixtures (274). [Pg.274]

Luminol chemiluminescence has also been recommended for measuring bacteria populations (304,305). The luminol—hydrogen peroxide reaction is catalyzed by the iron porphyrins contained in bacteria, and the light intensity is proportional to the bacterial concentration. The method is rapid, especially compared to the two-day period required by the microbiological plate-count method, and it correlates weU with the latter when used to determine bacteria... [Pg.275]

For determination of low hydrogen peroxide concentrations, a chemiluminescent reagent system was developed consisting of oxalyldiimidazole and an immobilized fluorophore (3-aminofluoranthene) on an acrylate polymer.[47]... [Pg.415]

Observations Table 2 shows the levels of free radicals determined by luminol chemiluminescence, H202 levels, and membrane lipid peroxidation determined by conjugated dienes. Total free radicals significantly increased by 1.4 fold, hydrogen peroxide significantly decreased 1.3 fold, and lipid peroxidation increased significantly 1.5 fold. [Pg.145]

Mansouri A, Makris DP and Kefalas P. 2005. Determination of hydrogen peroxide scavenging activity of cinnamic and benzoic acids employing a highly sensitive peroxyoxalate chemiluminescence-based assay structure-activity relationships. J Pharm Biomed Anal 39(l-2) 22-26. [Pg.300]

Dubovenko et al. [180] used chemiluminescence to determine total chromium in brines. The method is based on the enhancement of the chemiluminescence by chromium in the reaction of 4-(diethylamino) phthalhydrazide with hydrogen peroxide. The detection limit is 0.025 pg/1 of chromium, and the chemiluminescence is directly proportional to chromium concentrations in the range 5 x 10 10 to 10 6 M. [Pg.157]

Sakamoto [243] determined picomolar levels of cobalt in seawater by flow injection analysis with chemiluminescence detection. In this method flow injection analysis was used to automate the determination of cobalt in seawater by the cobalt-enhanced chemiluminescence oxidation of gallic acid in alkaline hydrogen peroxide. A preconcentration/separation step in the flow injection analysis manifold with an in-line column of immobilised 8-hydroxyquinoline was included to separate the cobalt from alkaline-earth ions. One sample analysis takes 8 min, including the 4-min sample load period. The detection limit is approximately 8 pM. The average standard deviation of replicate analyses at sea of 80 samples was 5%. The method was tested and inter calibrated on samples collected off the California coast. [Pg.167]

HTAC cationic micelles also markedly enhance the CL intensity of fluorescein (FL) in the oxidation of hydrogen peroxide catalyzed by horseradish peroxidase (HRP) [39], However, no CL enhancement was observed when anionic micelles of sodium dodecyl sulphate (SDS) or nonionic micelles of polyoxyethylene (23) dodecanol (Brij-35) were used (Fig. 9). CL enhancement is attributed to the electrostatic interaction of the anionic fluorescein with the HTAC micelles. The local concentration of fluorescein on the surface of the micelle increases the efficiency of the energy transferred from the singlet oxygen (which is produced in the peroxidation catalyzed by the HRP) to fluorescein. This chemiluminescent enhancement was applied to the determination of traces of hydrogen peroxide. The detection limit was three times smaller than that obtained in aqueous solution. [Pg.298]

Finally, Yamada and Suzuki made a comparative study of the use of DDAB, HTAB, STAC, and CEDAB to improve the sensitivity and selectivity of the determination of ultratraces of Cu(II) by means of the CL reaction of 1,10-phenanthroline with hydrogen peroxide and sodium hydroxide, used as detection in a flow injection system [46]. Of the four cited surfactants it was found that CEDAB causes the greatest enhancement of the chemiluminescent signal (Fig. 12) (an enhancement factor of 140 with respect to the absence of surfactant). [Pg.303]


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