Carbon analyses

Gravimetric analysis, carbon black, quartz, silica... 

Ethyl propiolate was used as received from Aldrich Chemical Company, Inc. (pure by 400 MHz 1H NMR analysis). Carbon tetrachloride was spectrophotometric grade and was used without purification. 

The primary dispersion halo and wallrock alteration around the Elura deposit was established from integrated petrographic, mineralogical and geochemical (major-, minor- and trace-element) analysis of diamond drill core samples. Seventy eight samples of variably altered and unaltered host rocks, as well as 67 near-surface weathered equivalents, were analysed for major elements using fusion disc. X-ray fluorescence analysis (XRF). Trace elements were determined by pressed powder XRF analysis. Carbonate carbon... 

Many of the test methods applied to coal analysis are empirical in nature, and strict adherence to the procedural guidelines is necessary to obtain repeatable and reproducible results. The type of analysis normally requested by the coal industry may be a proximate analysis (moisture, ash, volatile matter, and fixed carbon) or an ultimate analysis (carbon, hydrogen, sulfur, nitrogen, oxygen, and ash). 

Fig. 7.9 The molecular structures of butadiene and cyclooctatetraene iron tricarbonyl determined by X-ray structure analysis (carbon and hydrogen atoms of the olefmic ligands are omitted for clarity)...

K. L. Luthra, Oxidation of Carbon/Carbon Composites—A Theoretical Analysis, Carbon, 26, 217-224 (1988). 

Chemical and Physical Analysis. Carbon on the aged catalysts was determined by combustion, and metals were determined by wet chemical analysis and atomic absorption. Surface areas and pore volumes were measured by the standard BET method using nitrogen and the mercury porosimetry, respectively. All analyses were given on a fresh catalyst basis. 

Isotope ratios are normally not measured on the pure element, but rather on a gas containing the element that is convenient for the mass-spectrometric analysis. Carbon and oxygen isotope ratios are normally measured in CO2, which means R = C02/ C02 and R = based on measurements of the mass ratios 45/44 and 46/44 (the mass to charge ratio, m/z, of the ionized form of the molecules is determined in practice). This is significant because there can be contributions to these mass units other than the measured molecules. For CO2, corrections must be made, for example, for the occurrence of (mass 45 ... 

Quantitative elemental analysis carbon, hydrogen, and halogen... 

Elemental Analysis. Carbon, hydrogen, nitrogen, oxygen, sulfur, phosphorous, and ash determinations were made on freeze-dried samples of raw foam, and humic and fulvic acids isolated from Como Creek and Suwannee River foam and water samples by Huffman Laboratories (Golden, CO). Trace-metal analysis was performed on freeze-dried Como Creek foam by Huffman Laboratories (Golden, CO). 

Off-Gas Analysis. Gas samples are initially cleaned of particulates and dried to 2% moisture before analysis. Carbon monoxide and carbon dioxide are measured continuously using a Horiba Mexa-300 CO analyzer and a Horiba Mexa-200 CO2 analyzer. Syringe samples are taken downstream of the CO2 analyzer for gas chromatographic analysis, A room temperature molecular sieve 13X column is used to analyze for carbon monoxide, oxygen, and nitrogen, A Poropak Q column at 130°C is used to analyze for carbon dioxide, methane, ethane, ethylene, sulfur dioxide, and hydrogen sulfide. 

Apart from chemical analysis, thermoluminescence (TL), isotope analysis, Carbon 14 (14C) dating and several methods using thin sections should be mentioned here as further techniques applied to ceramics. 

For nonmetallic materials, the sample is often supported on an electrode whose emission spectrum will not interfere with the analysis. Carbon is an ideal electrode material for many applicatioits. Itcan be obtained in a highly pure form, is a good conductor, has good heal resistance, and is easily shaped. Manufacturers offer carbon electrodes in many sizes, shapes, and forms. Frequently, one of the electrodes is a cylinder with a small crater drilled into one end the finely ground... 

The spent catalysts were characterized by chemical analysis (carbon content), temperature programmed oxidation coupled to a mass spectrometer (TPO/MS) and thermal analysis (DTA and TG). The samples were also submitted to extraction of soluble coke in a soxhiet apparatus with n-hexane and dichloromethane for 24h, after being treated with fluoridric acid (40%) at room temperature (2h), followed by reflux with hydrocloric acid (36%) for 2h. The extracts were analyzed by gas-chromatography-mass spectrometry (GC/MS), Fourier transformer infrared spectroscopy (FTIR), ultraviolet spectroscopy (UV) and X ray diffraction. The insoluble fraction was analyzed by X ray diffraction and FTIR. 

Penta- and Hexa-aza-compounds. 3,6-Dibenzyl-l,2,4,5-tetrazine (811) undergoes a complex reaction with methanolic potassium hydroxide, giving 3-benzyl-7-methoxy-6-phenylimidazo[l,2-6][l,2,4,5]tetrazine (812), whose structure has been elucidated by X-ray analysis.Carbon-13 n.m.r. spectroscopy has been used to investigate azido-tetrazole valence tautomerism for the systems (813) and (814)" and for (815) (816) (817)." ... 

Compound Ligand(g) Solvent Color mp ( C) Analysis Carbon Hydrogen Calcd. Found /Calcd. Found ... 

Typical analysis (%) Carbon 0.33 Silicon 0.35 Manganese 1.35 Chromium 16.7 Sulfur 0.12... 

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