Chemiluminescence measurement

Chemiluminescence is the light emitted during chemical processes, e.g. oxidation (thermal- and/or photo-oxidation) or decomposition of peroxides and hydroperoxides [721]. 

Chemiluminescence occurs in the termination step of the oxidative degradation of polymers  

Chemiluminescence measurement is based on the detection of the chemiluminescence light intensity (at constant temperature) versus time (Fig. 10.44). 

The maximum light intensity emission (/ ax) at the point at which steady-state oxidation is reached. 

The induction period ( 1/2), i e. the time required for the light intensity to reach one half of the maximum light intensity emission (/max)- 

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The device for nitrogen oxides based on chemiluminescence measures the nitrogen monoxide concentration. The same equipment can be used to measure the concentration of nitrogen dioxide. Nitrogen dioxide is reduced to nitrogen monoxide in a converter by a molybdenum catalyst. In order to... 

Recently, we have shown that non-isothermal chemiluminescence measurements for oxidized cellulose provide the same rate constants of cellulose degradation as may be measured from experiments on the decay of polymerization degree determined by viscometry. This may be also taken as indirect evidence that the light emission is somehow linked with the scission of polymer chains [29]. 

Table 4 The effect of antioxidants on induction time of oxidation of polypropylene determined at 150°C from chemiluminescence measurements...

We would like to thank Dr. I. Lacik from Polymer Institute of the Slovak Academy of Sciences who undertook the GPC experiments, Dr. Jose Manuel Gomez-Elvira from CSIC Madrid, Spain who supplied PP of various initial molar masses, Dr. M. Pletenikova who performed some chemiluminescence measurements, Papylum project of the 5th EU community programme, Grant Agency VEGA for the grants No. 2/5109/25 and 2/6115/26 and the project KNIHA-SK. 

Figure 7. (a) Flow diagram of the optical fibre continuous-flow system for bioluminescence and chemiluminescence measurements S, sample C, carrier stream PP, peristaltic pump IV, injection valve W, waste FO, optical fibre FC, flow-cell, (b) Details of the optical fibre biosensor/flow-cell interface a, optical fibre b, sensing layer c, light-tight flow-cell d, stirring bar. 

Composite sensing layers, consisting of bioactive molecule-charged beads entrapped in a polymeric structure, have been successfully used to realize multi-purpose biochips for DNA, proteins or enzymes. For all these different biochips, the chemiluminescence and electro-chemiluminescence measurements required only a CCD camera and neither light sources nor optical filters are needed. 

Williams, D.C., Huff, G.F., and Seitz, W.R. (1976) Glucose oxidase chemiluminescence measurement of glucose in urine compared with the hexokinase method. Clin. Chem. 22, 372. 

A.N. Diaz, F.G. Sanchez, M.C. Ramos, and M.C. Torijas, Horseradish peroxidase sol-gel immobilized for chemiluminescence measurements of alkaline-phosphatase. Sens. Actuat. B 82, 176-179 (2002). 

A BASIC FLOW INJECTION SYSTEM FOR CHEMILUMINESCENCE MEASUREMENTS... 

The solution of this problem was to design a device with circular sample transfer. Irradiation and chemiluminescence measurement are spatially separated ... 

Chemiluminescence measurements were performed on X-ray film or Polaroid 20,000 ASA film using a camera luminometer (Tropix, Inc., Bedford, MA). The microplate luminometer we use is the Lucy 1 (Anthos Labtec Instruments, Wals, Austria). Black, white, and transparent microtiterplates and strips were from Corning Costar (Badhoevedorp, The Netherlands). 

Figure 7.6. Activation of neutrophils in unfractionated blood. Unfractionated, whole blood (10 p ) was diluted to 1 ml in RPMI 1640 medium and incubated in the absence (un-primed) or presence (primed) of 50 U/ml GM-CSF for 60 min at 37 °C. After this incubation, luminol was added (to 100 pM, final concentration) and chemiluminescence measured after the addition of 1 pM fMet-Leu-Phe.

Figure 7.12. Role of protein biosynthesis in the ability of neutrophils to generate reactive oxidants. Neutrophils were incubated in the presence (O) and absence ( ) of 30 pg/ml cycloheximide at 37 °C. At time intervals, portions were removed and luminol chemiluminescence measured after stimulation with 1 pM fMet-Leu-Phe. Values presented are a percentage of the control value measured at time zero.

Fontijn, A., A. J. Sabaddl, and R. J. Ronco. Homogeneous chemiluminescent measurement of nitric oxide with ozone. Anal. Cbem. 42 575-579, 1970. 

For chemiluminescence measurements, a postcolumn reactor with a pulse-dampening filter was added to the HPLC apparatus. A 3-cm piece of narrow-bore tubing joined the pulse dampener to a Valeo l-/tl T chemiluminescent reagent with the chromatographic eluent. A C8 ECONOSPHERE (250 X 4.6-mm ID) column was used. Modifications were made with the... 

The optically active 1,2-dioxetane of 2,4-adamantanedione (89) was synthesized. Thermal activation of 89 yielded chemiluminescence (Xmax = 420 nm characteristic of ketone fluorescence), pointing to intermediate 90 which is chiral only in its excited state due to the out-of-plane geometry of one of the two carbonyl groups. However, circular polarization of chemiluminescence measurement of 90 has not detected optical activity at the moment of emission. The authors have concluded that fast, relative to the lifetime of ketone singlet excited state, intramolecular n, it energy transfer caused racemization of 90196. 

High signal-to-noise ratio and high sensitivity due to the chemiluminescence measurement... 

Kohler et al. discussed the potential of the chemiluminescence technique as an industrial test method. Imaging chemiluminescence was used to assess antioxidant performance. An advantage over oven aging was found to be the possibility for evaluation of the oxidative stability of samples with unusual geometries, such as fibres and powder particles [136]. A correlation was also found between oven aging and chemiluminescence measurements on stabilised PP and it was shown that chemiluminescence measurements done at... 

L17. Lissi, E., Salim-Hanna, M., Pascual, C., and del Castillo, M. D., Evaluation of total antioxidant potential (TRAP) and total antioxidant reactivity from luminol-enhanced chemiluminescence measurements. Free Radic. Biol. Med. 18, 153-158 (1995). 

In addition to surprisal analysis of measured product energy distributions, surprisal synthesis has been applied [178] to the prediction of energy distributions either by induction from some more limited experimental data or by deduction from some dynamical calculation. In the inductive approach to surprisal synthesis, the available experimental data is used as a constraint to compute the surprisal parameter, X, by ensuring that the entropy is maximised. This surprisal parameter then determines a more detailed distribution. In a more modest way, this approach may be used to extend incomplete product energy distributions. For example, as mentioned before, infrared chemiluminescence measurements are incapable of determining the population of products in the vibrational ground state, v = 0, and this is often induced from the surprisal analysis of the other vibrational levels. 

For the reactions H, D + Br2 there has been less experimental confirmation about the product vibrational and rotational energy disposal. Fast-flow infrared chemiluminescence measurements [241] yield a product vibrational distribution that differs from earlier measurements [228]. A recent molecular beam study [235] for D + Br2, at a lower collisional energy (5.3 kJ mole-1) than the earlier beams studies ( 42 kJ mole-1), gives CFX> = 0.40, which agrees more closely with the 300 K chemiluminescence value, CFX> = 0.41 [228], than does the higher energy beams value [111] of (FT) = 0.31. 

Infrared chemiluminescence measurements [581] of the HF products from the reactions of fluorine atoms with a wide range of pure and halogenated olefinic and aromatic hydrocarbons (see list in Table 7)... 

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