Chemiluminescence models

McCapra, F., and Manning, M. J. (1973). Bioluminescence of coe-lenterates chemiluminescent model compounds. Chem. Commun., pp. 467- 468. 

Antioxidants have been shown to improve oxidative stabiHty substantially (36,37). The use of mbber-bound stabilizers to permit concentration of the additive in the mbber phase has been reported (38—40). The partitioning behavior of various conventional stabilizers between the mbber and thermoplastic phases in model ABS systems has been described and shown to correlate with solubiHty parameter values (41). Pigments can adversely affect oxidative stabiHty (32). Test methods for assessing thermal oxidative stabiHty include oxygen absorption (31,32,42), thermal analysis (43,44), oven aging (34,45,46), and chemiluminescence (47,48). 

In this work the development of mathematical model is done assuming simplifications of physico-chemical model of peroxide oxidation of the model system with the chemiluminesce intensity as the analytical signal. The mathematical model allows to describe basic stages of chemiluminescence process in vitro, namely spontaneous luminescence, slow and fast flashes due to initiating by chemical substances e.g. Fe +ions, chemiluminescent reaction at different stages of chain reactions evolution. 

The mathematical model was based on the scheme utilized in chemiluminescent method that was supplement with the reactions of radicals, formed of inhibitor molecules - AO. 

Formation of the excited amide anion of coelenteramide as the light emitter in the luminescence reaction of coelenterazine was experimentally supported by the experiment of Hori et al. (1973a), in which 2-methyl analogue of coelenterazine was used as the model compound. The summary of their work is as follows In the presence of oxygen, la and lb in DMF emitted bright blue luminescence (Amax 480 and 470 nm, respectively), and produced the reaction products Ha and lib, respectively. The fluorescence emission of lib (Amax 470 nm) and that of the spent chemiluminescence reaction of lb, both in DMF plus a base (potassium r-butoxide), were identical to the chemiluminescence emission of lb in DMF. The fluorescence emission of Ha... 

In the activation of PS-A and PS-B, treatment with methylamine resulted in a considerably higher chemiluminescence activity than with other amines. In the case of K-1, however, a significantly higher chemiluminescence activity was obtained with (NH SC or with hexy-lamine than with methylamine. In spite of this finding, methylamine was used in the activation of K-1 to prepare a model compound of PM. 

Fig. 9.10 Absorption spectra of K-1 (a model compound) and its chemiluminescent methylamine-activation products KM-1 and KM-2. All in methanol.

Treatment of the precursors with decylamine resulted in a high level of chemiluminescence activity. Taking the activity obtained with decylamine as 100%, the activities obtained with other amines were methylamine, 5% hexylamine, 23% octylamine, 39% and dode-cylamine, 55%. For comparison, the Panellus precursors, PS-A and PS-B, are best activated with methylamine, and a synthetic model compound, K-l, is best activated with hexylamine. 

Cutler, M. W., and Ward, W. W. (1997). Spectral analysis and proposed model for GFP dimerization. In Hasting, J.W., et al. (eds.), Bioluminescence and Chemiluminescence Molecular Reporting with Photons, pp. 403-406. Wiley, New York. 

Goto, T., and Fukatsu, H. (1969). Cypridina bioluminescence VII. Chemiluminescence in micelle solutions — A model system for Cypridina bioluminescence. Tetrahedron Lett., pp. 4299-4302. 

In order to optimize the chemiluminescence response, we have investigated the mechanism of the complex reactions leading to chemical generation of chemiluminescence. A new peroxyoxalate-hydrogen peroxide reaction mechanism has emerged from our preliminary studies on the five contributing factors listed above. Two kinetic models are discussed, one for the... 

This model permits a determination of the rate constants for the rise of the chemiluminescence intensity and its subsequent decay and, more importantly, allows a quantitative assessment of the effects of reaction conditions, such as solvent variation, temperature, or additives, on the rates (r and f), the time required (t... 

Figure 13, indicates that the first mole of phenol is released in <30 s, the same elapsed time for the chemiluminescence to reach a maximum intensity. In fact, the measured rate constant r, for the rise in the chemiluminescence emission, is identical to the rate of the first phenol s release from the oxalate ester. Furthermore, the slower rate of release of the second phenol ligand has a rate constant that is identical to the chemiluminescence decay rate f. Thus, the model allows a quantitative analysis of the reaction mechanism, heretofore not available to us. We intend to continue this avenue of investigation in order to optimize the chemiluminescence efficiencies under HPLC conditions and to delineate further the mechanism for peroxy-oxalate chemiluminescence. 

Figure 9 Isothermal chemiluminescence from oxidation of dicaproyl hexamethylene diamide CH3-(CH2)4CONH-(CH2)6-NHCO-(CH2)4-CH3 (model of polyamide) in oxygen.

Based on IgG-bearing beads, a chemiluminescent immuno-biochip has been also realized for the model detection of human IgG. Biotin-labeled antihuman IgG were used in a competitive assay, in conjunction with peroxidase labelled streptavidin59. In that case, the planar glassy carbon electrode served only as a support for the sensing layer since the light signal came from the biocatalytic activity of horseradish peroxidase. Free antigen could then be detected with a detection limit of 25 pg (108 molecules) and up to 15 ng. 

Certain Schiff bases, i.e. 122, were synthesized as model compounds for Latia luciferin. This compound exhibits strong blue chemiluminescence ( max 385 nm) on oxidation with oxygen in DMSO/potassium t.-butylate, the main products being acetone and 2-formamido pyridine 124. The mechanism suggested by Me Capra and Wrigglesworth includes the concerted bond cleavage of a dioxetane derivative 123. 

In Latia bioluminescence the ketone 121 was detected as product. Similarly, the chemiluminescence of imidazol-pyridinones 125 represents a model for Cypridina bioluminescence 181>. 

Optimization strategies and a number of generalized limitations to the design of gas-phase chemiluminescence detectors have been described based on exact solutions of the governing equations for both exponential dilution and plug-flow models of the reaction chamber by Mehrabzadeh et al. [12, 13]. However, application of this approach requires a knowledge of the reaction mechanism and rate coefficients for the rate-determining steps of the chemiluminescent reaction considered. 

Mitsubishi supply two total nitrogen analysers the model TN-10 and the model TN-05 microprocessor control chemiluminescence total nitrogen analysers (Fig. 1.8 (a)). 

Several methods have been developed to estimate the exposure to such emissions. Most methods are based on either ambient air quality surveys or emission modeling. Exposure to other components of diesel emissions, such as PAHs, is also higher in occupational settings than it is in ambient environments. The principles of the techniques most often used in exhaust gas analysis include infrared (NDIR and FTIR), chemiluminescence, flame ionization detector (FID and fast FID), and paramagnetic methods. 

NOx-analyser Thermoelectron Model 10, chemiluminescent S02-analyser Heraeus Binos,UV-Vis CO- and C02-analysers Leybold-Heraeus Binos 1, ND-IR 02-analyser Hartman-Brown Magnos 3, paramagnetic. 

Exhaust gas temperature measurements are made with a fine-wire R-type thermocouple connected to an Omega model 660 digital readout. Gas samples are extracted using a 6.4-millimeter (0.25-inch) O.D. water-cooled stainless-steel suction probe and then filtered, dried, and analyzed for CO, CO2, O2, UHC, and NOj . Instrumentation includes a Beckman model 864 NDIR CO2 analyzer, Beckman model 867 NDIR CO analyzer, Siemens OXYMAT 5E paramagnetic O2 analyzer, Siemens FIDAMAT 5E-E FID total hydrocarbon analyzer, and a Beckman model 955 Chemiluminescent NO/NOj, analyzer. Certified span gases are used for instrument calibration. PC-based data acquisition is available during experimentation. All of the emissions data reported here were obtained approximately 24 pipe diameters downstream of the fuel injector and represent average exhaust concentrations. 

The cleavage of 1,2-dioxetanes constitntes the model chemiluminescent process, which may be initiated thermally, by electron transfer or in catalytic reactions (e.g. in complexes formed between dioxetanes and transition metals). In the subsequent subsections, we review the most recent significant developments in this area. 

Photoinduced electron transfer from eosin and ethyl eosin to Fe(CN)g in AOT/heptane-RMs was studied and the Hfe time of the redox products in reverse micellar system was found to increase by about 300-fold compared to conventional photosystem [335]. The authors have presented a kinetic model for overall photochemical process. Kang et al. [336] reported photoinduced electron transfer from (alkoxyphenyl) triphenylporphyrines to water pool in RMs. Sarkar et al. [337] demonstrated the intramolecular excited state proton transfer and dual luminescence behavior of 3-hydroxyflavone in RMs. In combination with chemiluminescence, RMs were employed to determine gold in aqueous solutions of industrial samples containing silver alloy [338, 339]. Xie et al. [340] studied the a-naphthyl acetic acid sensitized room temperature phosphorescence of biacetyl in AOT-RMs. The intensity of phosphorescence was observed to be about 13 times higher than that seen in aqueous SDS micelles. 

This paper presents analysis methods for compounds fo defermine fheir general biological acfivity. Characferisfics of the methods in model systems using different antioxidant reaction mechanisms are also described. Both colorimetric methods and those with fluorometric detection as well as chemiluminescence testing are included. 

Robbat, A., Jr., N. P. Corso, P. J. Doherty, and M. H. Wolf, Gas Chromatographic Chemiluminescent Detection and Evaluation of Predictive Models for Identifying Nitrated Polycyclic Aromatic Hydrocarbons in a Diesel Fuel Particulate Extract, Anal. Chem., 58, 2078-2084 (1986). 

Part of the radiation from the reaction Zone of this flame is nonthermal, being chemiluminescent in origin. In determination of populations of species such as C2 and CH in low-pressure diffusion or premixed flames at 1-15 torr, these authors developed a simple model of a flame which reflects the characteristic requirements for start of laser action. They show that by choice of the proper experimental parameters in the model, laser action should be attainable... 

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