Quantitative analysis carbon monoxide

Carbon Monoxide Oxidation. Analysis of the carbon monoxide oxidation in the boundary layer of a char particle shows the possibility for the existence of multiple steady states (54-58). The importance of these at AFBC conditions is uncertain. From the theory one can also calculate that CO will bum near the surface of a particle for large particles but will react outside the boundary layer for small particles, in qualitative agreement with experimental observations. Quantitative agreement with theory would not be expected, since the theoretical calculations, are based on the use of global kinetics for CO oxidation. Hydroxyl radicals are the principal oxidant for carbon monoxide and it can be shown (73) that their concentration is lowered by radical recombination on surfaces within a fluidized bed. It is therefore expected that the CO oxidation rates in the dense phase of fluidized beds will be suppressed to levels considerably below those in the bubble phase. This expectation is supported by studies of combustion of propane in fluidized beds, where it was observed that ignition and combustion took place primarily in the bubble phase (74). More attention needs to be given to the effect of bed solids on gas phase reactions occuring in fluidized reactors. 

Carbon monoxide may be determined over a wide range of concentration via infrared analysis [25]. Good results are achieved at concentrations as low as 1.25 to 2.5 mg m . The main disadvantage of this technique is the non-linear response, as well as possible interference by CO2, water vapour and hydrocarbons. The use of the gas chromatography for determining CO includes a catalytic reduction system, which converts carbon monoxide quantitatively to methane and a flame ionization detector. For a rapid CO determination, indicator tubes with palladium salt as a catalyst and silicomolybdate complex, which yields a blue colour with carbon monoxide, are used. The CO determination can also be carried out on the basis of its reaction with the radioactive kryptonate of palladium chloride [18, 25]. 

Several quantitative procedures for concentrations above 0.1 vol % are available. Gas chromatographic analysis (78) is particularly useful because it is fast, accurate, and relatively inexpensive. The standard wet-chemical, analytical method (76) takes advantage of the reaction between iodine pentoxide and carbon monoxide at 423 K. 

A sophisticated quantitative analysis of experimental data was performed by Voltz et al. (96). Their experiment was performed over commercially available platinum catalysts on pellets and monoliths, with temperatures and gaseous compositions simulating exhaust gases. They found that carbon monoxide, propylene, and nitric oxide all exhibit strong poisoning effects on all kinetic rates. Their data can be fitted by equations of the form ... 

Elemental composition Ni 34.38%, C 28.13%, O 37.48%. The compound may be identified and measured quantitatively by GC/MS. An appropriately diluted solution in benzene, acetone, or a suitable organic solvent may be analyzed. Alternatively, nickel tetracarbonyl may be decomposed thermally at 200°C, the liberated carbon monoxide purged with an inert gas, and transported onto the cryogenically cooled injector port of a GC followed by analysis with GC-TCD on a temperature-programmed column. Nickel may be analyzed by various instrumental techniques following digestion of the compound with nitric acid and diluting appropriately (See Nickel). 

Carbon Monoxide. Methods for determining carbon monoxide include detection by conversion to mercury vapor, gas filter correlation spectrometry, TDLAS, and grab sampling followed by gas chromatograph (GC) analysis. The quantitative liberation of mercury vapor from mercury oxide by CO has been used to measure CO (73). The mercury vapor concentration is then measured by flameless atomic absorption spectrometry. A detection limit of 0.1 ppbv was reported for a 30-s response time. Accuracy was reported to be 3% at tropospheric mixing ratios. A commercial instrument providing similar performance is available. 

Gas phase chromatography has shown a very rapid development. Small units with more sensitive effluent gas analyzers are being marketed. Although its potentialities with respect to utility in clinical laboratories have not been fully assessed, it may well make possible the rapid and quantitative analysis of blood oxygen, carbon dioxide, carbon monoxide, methanol, ethanol, and fatty acids. 

Mosl types of spectroscopy can be used for quantitative analysis because the intensity of an absorption band—that is, the amount of light absorbed at a particular wavelength—is proportional to the amount of compound in the sample. A group of chemists at the University of Denver has developed a device that can measure the amount of carbon monoxide and hydrocarbons in the exhaust of an automobile by remote sensing— that is, in the street as the automobile passes by. 

Mass spectral analysis of the samples at several different temperatures show the exit gas stream to contain in addition to oxygen carbon dioxide, carbon monoxide, sulfur dioxide, and some carbonyl sulfide. The primary sulfur containing gas in the stream is sulfur dioxide ( 1%) however, a small amount of carbonyl sulfide ("0.1%) appears to be present. For any quantitative work it will be necessary to monitor the carbonyl sulfide or to optimize reaction conditions and/or add a secondary oxidation stage to decrease its concentration to a negligible level. It should be noted that mass spectral analysis of the exit gas during the sulfur dioxide peaks gave no evidence for the presence of gaseous hydrocarbons or sulfur trioxide. 

In the quantitative analysis of mixtures of cobalt carbonyl solutions, (Sternberg, Wender, and Orchin, 40) advantage is taken of the fact that aqueous solutions of iodine-potassium iodide react with [Co(CO)4]2 or Co(CO)4" to liberate all the carbon monoxide in the carbonyl ... 

In situ infrared reflectance spectroscopy investigation of the oxidation reaction of ethanol appears thus as an efficient method to elucidate some mechanistic aspects of the reaction. However, the quantitative analysis of the reaction products remains difficult due to different parameters the characteristic absorption band may not be monopolar (this is the case for carbon monoxide for example) and the difficulty to obtain a quantitative relationship between infrared extinction coefficients and concentration for reaction products and by-products. 

Newer methods of chemical analysis led to the isolation of the major alkaloids from crude drug preparations. By 1833, aconitine, atropine, codeine, hyoscyamine, morphine, nicotine, and strychnine had been isolated from plants. Color tests for alkaloids were developed between 1861 and 1882 by 1890 quantitative analysis methods became available. Physiological tests for alkaloids, particularly strychnine, first used in 1856, were employed well into the twentieth century. Tests for alcohol, devised by Lieben (iodoform crystal test, 1870) and others, were later perfected for the quantitative analysis of alcohol in body fluids and tissues. Qualitative tests for carbon monoxide in the blood were developed about this time and in 1880, Fodor developed a palladium chloride reduction method to quantitate carbon monoxide in blood. 

The first quantitative results for the decomposition of starch into carbon monoxide, carbon dioxide, and water are those of Puddington. He showed that pyrolysis of starch is more rapid under vacuum than at atmospheric pressure, that is, that the reaction probably does not involve oxidation. Puddington made a kinetic study of the decomposition of potato starch, in the narrow temperature range of 180-210°, at 10 mm. A conventional, vacuum line of glass permitted the pyrolysis products to be trapped or collected. The amounts of carbon monoxide, carbon dioxide, and water were determined by classical, gas-analysis techniques. 

The quantitative aspect of the EXAFS technique is also well known and the literature gives several studies where chemisorption and EXAFS measurements are compared (see for example We can illustrate this particular contribution of the spectroscopy by a study of rare earth transition metal catalysts prepared from intermetallic LaNij-type compounds. The three classical preparation steps are here skipped with a carbon monoxide hydrogenation reaction. The intermetallic phase is transformed into a rare earth oxide upon which the transition metal is left as metallic clusters which form the active species. This transformation has been followed as a function of the time reaction In Fig. 5 we plot the Fourier transforms of CeNij at the nickel edge before the reaction (a), after 10 hours (b) and after 27 hours (c) under the CO + H2 mixture. These are all compared to elemental nickel (d). The increase of the amplitude of the first peak and the growth of three new ones at greater distances are the consequence of the formation of nickel particles. A careful analysis of these four shells has allowed us quantitatively to estimate the fraction of extracted nickel during the reaction as 30% after 10 hours and 80% after 27 hours on a CO + flux at 350 °C. 

When dedicated quantitative work is required in IR, simple filter instruments (also called photometers) are often used. These employ a narrow bandpass filter with a wavelength that corresponds to the absorption of the component being measured. This type of absorption is the more popular method for gas analysis, e.g. carbon monoxide, nitrogen dioxde and methane. It is also possible to have variable bandpass filters for use in scanning instruments. These are rugged and reliable dedicated analysers and commonly used in on-line systems. 

Kruszynski, A.J. and A. Henriksen Die quantitative Bestimmung von Kohlenmonoxid im Tabakrauch [The quantitative determination of carbon monoxide in tobacco smoke] Beitr. Tabakforsch. 5 (1969) 9-12. Kubota, H., M.R. Guerin, and J.A. Carter Inorganic analytical methods of tobacco smoke analysis A comparative smdy 26th Tobacco Chemists Research Conference, Program Booklet and Abstracts, Vol. 26, Paper No. 23, 1972, p. 35. 

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