Nitric oxide chemiluminescence

Chemiluminescence. Chemiluminescence (262—265) is the emission of light duting an exothermic chemical reaction, generaUy as fluorescence. It often occurs ia oxidation processes, and enzyme-mediated bioluminescence has important analytical appHcations (241,262). Chemiluminescence analysis is highly specific and can reach ppb detection limits with relatively simple iastmmentation. Nitric oxide has been so analyzed from reaction with ozone (266—268), and ozone can be detected by the emission at 585 nm from reaction with ethylene. 

Nitric oxide (NO) and nitrogen dioxide (NO2) were monitored by a Bendix chemiluminescence instrument. However, since the "NO2" readings of this type of instrument are known to include the contribution of HNO3, HONO, PAN, and other organic nitrates ( ), we report these readings as "gaseous nitrate."... 

J.S. Beckman and K.A. Congert, Direct measurement of dilute nitric oxide in solution with an ozone chemiluminescent detector. Methods 7, 35-38 (1995). 

J.K. Robinson, MJ. Bollinger, and J.W. Birks, Luminol/H202 chemiluminescence detector for the analysis of nitric oxide in exhaled breath. Anal. Chem. 71, 5131-5136 (1999). 

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 associative reaction of oxygen atoms with nitric oxide produces the yellow-green chemiluminescence in the air afterglow, easily seen by the naked eye. The reaction has long been used to measure the concentrations of O atoms in kinetics experiments [49-51] and is so bright that it has been used to visualize... 

Macrophages from endrin-exposed rats or mice showed an increase in the concentration of nitric oxide (Akubue and Stohs 1992 Bagchi et al. 1993d) and increased chemiluminescence and production of superoxide anion (Bagchi et al. 1993a). Based on these results and those described above for hepatic... 

The technol( for the routine measurement of the nitrogen oxides (nitrogen dioxide and nitric oxide) is fairly well advanced. The epa is on the verge of officially proposing that chemiluminescence produced by the reaction of nitric oxide with ozone be the reference method for nitrogen dioxide.This method is even more suitable for nitric oxide. Because no national air quality standard has been promulgated for nitric oxide, no reference method will be specified. However, its measurement in the atmosphere is crucial for establishing the relation of its emission to the formation of atmospheric ozone and other photochemical oxidants. 

In the chemiluminescent detection of nitrogen oxides, a constant source of ozone reacts with a metered air sample containing nitric oxide. Fontijn et al. suggested that this method could also be used for ozone detection by using a constant nitric oxide source for reaction with ozone in the air sample. The ozone-nitric oxide reaction is carried out at reduced pressure, to avoid quenching the chemiluminescent reaction. Detection of the emission in the spectral r on involved (600-3,000 nm) requires using a near-infrared-sensitive photomultiplier tube. The noise of such a photomultiplier tube is reduced by cooling it to about - 20 C. ... 

The calibration of a chemiluminescent analyzer using these standards is verified when both the nitrogen dioxide and nitric oxide channels respond similarly to charges from the (ylinder of diluted nitric oxide. Agreement with the response of the nitric oxide channel should also be obtained when the standard nitric oxide mixture is titrated with a previously established source of ozone. Chemiluminescent instruments have simplified monitoring of nitrogen oxides, but accurate calibration requires well-trained personnel. 

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

NO Nitric oxide is most commonly measured using the chemiluminescence from its reaction with 03 described earlier. One such instrument designed for high-sensitivity (1- to 2-ppt detection limit in 10 s) is described by Ridley and Grahek (1990). 

Nitric oxide release from blood vessels was first detected by chemiluminescence (Palmer et ai, 1987). In the original adaptations of the nitric oxide detector, perfusates from isolated vessels were directly mixed in a reflux chamber containing acetic acid and iodine. The iodine in the reflux chamber served to reduce any nitrites or nitroso-containing groups to nitric oxide, which was stripped from the chamber by a continuous stream of nitrogen or helium that flowed to the chemiluminescent detector. Replacement of the acetic acid with the less volatile trichloroacetic acid reduces problems with contamination of the nitric oxide detector (Dr. D. Harrison, Emory University, Atlanta, Georgia, personal communication, 1991). While extremely sensitive, the use of the acid reflux chamber also reduces the specificity of the assay, raising questions as to whether nitric oxide or a nitrosothiol is EDRF (Myers et ai, 1990). 

Kooy and Royall (1994) have shown that cultured endothelial cells produce peroxynitrite when stimulated by bradykinen. They used an ultrasensitive chemiluminescent assay based on luminol developed by Radi et al. (1993). Peroxynitrite is a potent toxin to trypanosomes, attacking both sulfhydryl dependent enzymes and respiratory enzymes (Rubbo et al., 1994). Radi et al. (1994) have also shown that it is far more damaging to mitochondria than nitric oxide. 

Wang, j. F., Komarov, P., Sies, H., and DeGroot, H. (1991). Contribution of nitric oxide synthase to luminol-dependent chemiluminescence generated by phorbol-ester-acti-vated Kupffer cells. Biochem.J. 279, 311-314. 

Thus, for a nitric oxide sensor dependent on ozone chemiluminescence, a 1.5-liter reaction chamber operating at 60 torr with a flow of 1.0 standard liter per second has a residence time of approximately t = (1.5/1.0) X (60/ 760) = 0.12 s. 

Banded optical emission results from electronically excited nitric oxide. The y and /S bands are often observed. Furthermore, chemiluminescence results from the well-studied step... 

Clyne, Thrush, and Wayne107 reexamined the chemiluminescence from the nitric oxide-ozone reaction and found its spectrum to be similar to that of the thermal emission of N02 at 1200°K. They concluded that the spectra represented transitions from similar low-lying vibration levels of the same excited electronic state of NOa to the ground state. By measuring the decay in chemiluminescence down a flow tube, they obtained the value of the rate constant between 216 and 322°K. The partial pressures of ozone and nitric oxide were 5 x 10-3 and 2 x 10 2 torr, respectively, in an argon carrier at a total pressure of 2 torr. In the presence of excess nitric oxide, they assumed the logarithmic disappearance of ozone proportional to [NO], so that... 

Cashion and Polanyi83 and Clement and Ramsay96 examined the red emission from about 6000 to 10,000 A resulting from the chemiluminescent reaction of hydrogen atoms with nitric oxide. The former authors observed emission from both vibrationally excited (2.9-3.6 p.)... 

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