Chemiluminescence technique

V. Ya. Shlyapiutokh and co-workers. Chemiluminescence Techniques in Chemical Reactions, Consultants Bureau, New York, 1968. 

Imaging chemiluminescence technique. Chemiluminescence analysis is suitable for studying the early stages of the thermal oxidation of rubbers. A weak emission of light formed by chemical reactions appears during the oxidative degradation of hydrocarbons. This technique can be used to depth profile the oxidation of rubbers. MR... 

Triantis T, Stelakis A, Dimotikali D and Papadopoulos K. 2005. Investigations on the antioxidant activity of fruit and vegetable aqueous extracts on superoxide radical anion using chemiluminescence techniques. Anal Chim Acta 536(1-2) 101-105. 

Chemiluminescent techniques have been used to determine nanomolar quantities of nitrate and nitrite in seawater [124,125]. This method depends on the selective reduction of these species to nitric oxide, which is then determined by its chemiluminescent reaction with ozone, using a commercial nitrogen oxides analyser. The necessary equipment is compact and sufficiently sturdy to allow shipboard use. A precision of 2nmol/l is claimed, and an analytical range of 2nmol/l with analysis rates of 10-12 samples hourly. 

The chemiluminescence technique has been used to determine trivalent chromium in seawater. Chang et al. [187] showed Luminol techniques for determination of chromium (III) were hampered by a salt interference, mainly due to magnesium ions. Elimination of this interference is achieved by seawater dilution and utilising bromide ion chemiluminescence signal enhancement (Fig. 5.7). The chemiluminescence results were comparable with those obtained by a graphite furnace flameless atomic absorption analysis for the total chromium present in samples. The detection limit is 3.3 x 10 9 mol/1 (0.2 ppb) for seawater with a salinity of 35%, with 0.5 M bromide enhancement. 

The most commonly used and widely marketed GC detector based on chemiluminescence is the FPD [82], This detector differs from other gas-phase chemiluminescence techniques described below in that it detects chemiluminescence occurring in a flame, rather than cold chemiluminescence. The high temperatures of the flame promote chemical reactions that form key reaction intermediates and may provide additional thermal excitation of the emitting species. Flame emissions may be used to selectively detect compounds containing sulfur, nitrogen, phosphorus, boron, antimony, and arsenic, and even halogens under special reaction conditions [83, 84], but commercial detectors normally are configured only for sulfur and phosphorus detection [85-87], In the FPD, the GC column extends... 

VYa Shlyapintokh, ON Karpukhin, LM Postnikov, YF Tsepalov, AA Vichutinskiy, IY Zakharov. Chemiluminescence Techniques in Chemical Reactions. New York Consultants Bureau, 1968. 

The use of chemiluminescence techniques therefore raises two questions. Firstly, what is the nature of the intracellular chemiluminescence Secondly, what reactive oxidant species are detected by this technique ... 

Thus, a chain reaction is set up in which HOz converts NO to NOz and is subsequently regenerated by the OH + CO reaction. The NOz is measured using techniques such as those described earlier in the case of the system in Fig. 11.52, the luminol chemiluminescence technique is used. Termination of the chain occurs via reactions such as... 

Continuous Measurement Methods for Trace Cases and Aerosols. Ozone. Three basic types of ozone instruments have been used in aircraft the ultraviolet photometric method and two chemiluminescent techniques measuring, respectively, light emitted from the reaction of 03 with ethylene and light emitted from the reaction of 03 with NO. Ultraviolet absorption photometry is one of the preferred methods for measuring 03 from aircraft because of the stability and reliability of commercially available instruments. The method is specific for 03 provided there are no immediate... 

Tunable diode laser absorption spectroscopy (TDLAS) has been used to measure oxides of nitrogen during flight (71). By tuning the laser to specific infrared absorption bands, the technique can selectively measure each compound. Detection limits are higher (25-100 pptrv for a 3-min response time) than the best chemiluminescent methods, and the instrumentation is less amenable to aircraft operations than the chemiluminescence techniques because of weight and size. 

Measurements of NO and N02 by Chemiluminescence. Most balloon-borne in situ measurements of NO and NO published to date have been made with the chemiluminescence technique (6, 63,64). Reagent ozone is added to the ambient flow in a reaction chamber, and the chemiluminescence observed from the reaction NO + 03 —> NO + 02 is detected by a photomultiplier tube that views the volume. The amount of light observed is proportional to the amount of NO in the ambient air. N02 is detected by exposing the ambient air going into the detection cell to a strong light source this exposure photolyzes N02 to NO, which can then be detected. 

A recent article (Ref 50 see Table 1 of Subsection A above) lists a=T. 1mm for 1.44g/cc RDX. Addition of various liqs generally increases the reaction zone width, as shown in Table 1 F. Characteristics of RDX Detonation Products. Volk (Ref 105) measured the fumes produced by the deton of RDX by gas chromatographic and chemiluminescence techniques. He identified h2, n2, co2, co, h2o, ch4, c2h6 c2h4... 

Wilkinson, D. (2000) Chemiluminescent techniques for western blot detection let researcher shed their lead aprons. The Scientist 14,29-32. 

Chemiluminescence technique has been used extensively at the department of Fibre and Polymer Technology at The Royal Institute of Technology (KTH) in Stockholm. Since the beginning of the 1990s when the first CL equipment was introduced at the department more than 31 papers [44, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83]and eight doctoral theses [84, 85, 86, 87, 88, 89, 9091] have been published where the chemiluminescence technique has been used, either as the main analytical technique or as a complement to other techniques. In this section, results from some of the investigations performed on polyolefins will be summarised. 

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... 

P20. Popov, I. N., and Lewin, G., Antioxidative homeostasis Characterization by menas of a chemiluminescent technique. Meth. Enzymol. 300, 437—456 (1999). 

Practical methods also have been reported for semicon-tinuous measurement of nitrate and carbon in particles from ambient air. For example, an instrument for nitrate monitoring uses collection of particles on an impactor surface, followed by flash volatilization and determination of the nitrate present using a chemiluminescence technique. Ion chromatographs also have been adopted for semicontinuous determination of gaseous and particulate nitrate. Real-time carbon analyzers also are available, one of which uses differential thermal analysis of impactor-collected material. 

Experiments are currently in progress to measure CO and NO concentrations in a flat flame burner by diode laser spectroscopy. Comparative measurements are also being made using microprobe sampling with subsequent analysis by non-dispersive infrared and chemiluminescent techniques. Some preliminary laser absorption results for CO are reported here initial results for NO have been published separately (4). Also reported are initial data for collision halfwidths in combustion gases. 

Difficulties are encountered in determining NO2 using the ozone-chemiluminescence technique due to the non-specific conversion of several nitrogen oxides/oxyacids on the Mo catalyst. Use of FeS04 f°r N02-to-N0 conversion has been described, but humidity-dependent sorption/desorption effects have been reported, e.g., PAN (11). Alternatively, a commercial NO2 analyzer based on surface chemiluminescence of NO2 in the presence of a luminol solution, has been introduced which exhibits the requisite sensitively and selectivity. 

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