Sulfur Oxide Analyzers

A sample of impure pyrite known to be approximately 90-95% w/w EeS2 is to be analyzed by oxidizing the sulfur to S04 and precipitating as BaS04. How many grams of the sample must be taken if a minimum of 1 g of BaS04 is desired ... 

At ID21 beamline p-XANES and p-XRF maps have been obtained along the same transects analyzed at ID18F. The maps were carried out in area of 100 x 100 pm with a resolution of 1 x 1 pm. The sulfur oxidation state was determined by scanning the energy of the exciting beam across the sulfur absorption K-edge (total-S = 2.55 KeV sulfide-S = 2.472 KeV sulfate-S = 2.482 KeV). 

Hafnium metal is analyzed for impurities using analytical techniques used for zirconium (19,21,22). Carbon and sulfur in hafnium are measured by combustion, followed by chromatographic or ir measurement of the carbon and sulfur oxides (19). Chromatographic measurement of liberated hydrogen follows the hot vacuum extraction or fusion of hafnium with a transition metal in an inert atmosphere (23,24). 

A compound is analyzed and found to be 50.0% sulfur and 50.0% oxygen. If the total amount of the sulfur oxide compound is 12.5 g, how many grams of sulfur are there ... 

One water sample, collected from the same highly inpacted well, was analyzed by the Wisconsin State Laboratory of Hygiene for iron- and sulfur-oxidizing bacteria. 

Oxidation of sulfur s functionality to a sulfone is one way of separating PAHs and PASHs, because the polar sulfones differ from unreacted nonpolar PAHs in their chromatographic behavior. The favored oxidant is metachloroperbenzoic acid (MCPBA). One major drawback of the oxidation approach is that with the exception of benzothiophenes (BT) and some of their alkyl derivatives, PASHs containing terminal thiophene rings are largely lost, probably by oxidation of other molecular features. Thus, the naphthothiophenes cannot be analyzed after oxidation with MCPBA. 

KEYWORDS ultra low sulfur, fuels, on-line process analyzers, thermal oxidation, pyrolysis, electrochemical sensors, nitrogen converters... 

Typical vehicle-inspection protocol requires motorists to bring the vehicle to a garage where automatic equipment samples exhaust and analyzes it for GO, aggregate hydrocarbons, nitrogen and sulfur oxides, and particulate matter. Some state departments of motor vehicles operate their own inspection stations, while others license private garages. There are a number of compact units on the market that provide the required information with little operator input. 

Gases analyzed include hydrocarbons, carbon monoxide, carbon dioxide, sulfur dioxide, sulfur trioxide, nitrogen oxides (also nitrous oxide, N2O), hydrogen chloride, hydrogen cyanide, ammonia, etc. 

EPR studies on electron transfer systems where neighboring centers are coupled by spin-spin interactions can yield useful data for analyzing the electron transfer kinetics. In the framework of the Condon approximation, the electron transfer rate constant predicted by electron transfer theories can be expressed as the product of an electronic factor Tab by a nuclear factor that depends explicitly on temperature (258). On the one hand, since iron-sulfur clusters are spatially extended redox centers, the electronic factor strongly depends on how the various sites of the cluster are affected by the variation in the electronic structure between the oxidized and reduced forms. Theoret-... 

The iron formed in a blast furnace, called pig iron, contains impurities that make the metal brittle. These include phosphorus and silicon from silicate and phosphate minerals that contaminated the original ore, as well as carbon and sulfur from the coke. This iron is refined in a converter furnace. Here, a stream of O2 gas blows through molten impure iron. Oxygen reacts with the nonmetal impurities, converting them to oxides. As in the blast furnace, CaO is added to convert Si02 into liquid calcium silicate, in which the other oxides dissolve. The molten iron is analyzed at intervals until its impurities have been reduced to satisfactory levels. Then the liquid metal, now in the form called steel, is poured from the converter and allowed to solidify. 

Conversion and the mean rate of reaction were obtained by titrating the liquid recovered from the bed for total acidity before and after dissolved S02 and sulfurous acid were oxidized to sulfuric acid. The difference between these measurements allowed calculation of the S02 conversion. An extension of the Haure study (Metzinger et al., 1992) added gas phase analysis and a check of the results through a sulfur balance. Computer control of flow interruption and acquisition of the S02 analyzer readings were also added. 

The Iodometric method has also been utilized in analyzing hydrogen sulfide in the air (EPA 1978). The method is based on the oxidation of hydrogen sulfide by absorption of the gas sample in an impinger containing a standardized solution of iodine and potassium iodide. This solution will also oxidize sulfur dioxide. The Iodometric method is suitable for occupational settings. The accuracy of the method is approximately 0.50 ppm hydrogen sulfide for a 30-L air sample (EPA 1978). 

Mathur and Thodos Chem. Eng. Sci., 21 (1191), 1966] used the initial rate approach to analyze the kinetics of the catalytic oxidation of sulfur dioxide. They summarized the most plausible rate controlling steps for the reaction as ... 

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