Total carbon determination

Total organic material as loss on ignition at 30 C Total carbon, determined by combustion analysis... 

Carbon-13 nmr. Carbon-13 [14762-74-4] nmr (1,2,11) has been available routinely since the invention of the pulsed ft/nmr spectrometer in the early 1970s. The difficulties of studying carbon by nmr methods is that the most abundant isotope, has a spin, /, of 0, and thus cannot be observed by nmr. However, has 7 = 1/2 and spin properties similar to H. The natural abundance of is only 1.1% of the total carbon the magnetogyric ratio of is 0.25 that of H. Together, these effects make the nucleus ca 1/5700 times as sensitive as H. The interpretation of experiments involves measurements of chemical shifts, integrations, andy-coupling information however, these last two are harder to determine accurately and are less important to identification of connectivity than in H nmr. 

A flame-ionization, total hydrocarbon analyzer determines the THC, and the total carbon content is calculated as methane. Other methods include catalytic combustion to carbon dioxide, which may be deterrnined by a sensitive infrared detector of the nondispersive type. Hydrocarbons other than methane and acetylene are present only in minute quantities and generally are inert in most appHcations. 

Total carbon in beryUium is determined by combustion of the sample, along with an accelerator mixture of tin, iron, and copper, in a stream of oxygen (15,16). The evolved carbon dioxide is usuaUy measured by infrared absorption spectrometry. BeryUium carbide can be determined without interference from graphitic carbon by dissolution of the sample in a strong base. BeryUium carbide is converted to methane, which can be determined directly by gas chromatography. Alternatively, the evolved methane can be oxidized to carbon dioxide, which is determined gravimetricaUy (16). 

Emission factors must be also critically examined to determine the tests from which they were obtained. For example, carbon monoxide from an automobile will vary with the load, engine speed, displacement, ambient temperature, coolant temperature, ignition timing, carburetor adjustment, engine condition, etc. However, in order to evaluate the overall emission of carbon monoxide to an area, we must settle on an average value that we can multiply by the number of cars, or kilometers driven per year, to determine the total carbon monoxide released to the area. 

Edmond, J. M. (1970). High precision determination of titration alkalinity and total carbon dioxide concentration of sea water by potentiometric titration. Deep-Sea Res. 17, 737-750. 

The composition of coal is conveyed by representing its proximate and ultimate analysis. The former implies determination of contents of moisture, volatile matter, fixed carbon, and ash, while the latter implies total carbon, hydrogen, oxygen, nitrogen, sulfur and ash. Here, an account will be provided of the constituents of coal, moisture, volatile matter, ash, fixed carbon, and some miscellaneous components. 

Various workers have discussed the determination of total alkalinity and carbonate [ 10-12], and the carbonate bicarbonate ratio [ 12] in seawater. A typical method utilises an autoanalyser. Total alkalinity (T milliequivelents per litre) is found by adding a known (excess) amount of hydrochloric acid and back titrating with sodium hydroxide solution a pH meter records directly and after differentiation is used to indicate the end-point. Total carbon dioxide (C milliequivelents per litre of HCO3 per litre) is determined by mixing the sample with dilute sulfuric acid and segmenting it with carbon dioxide-free air, so that the carbon dioxide in the sample is expelled into the air segments. The air... 

Fukushi and Hiiro et al. [24] described a method for determining total carbon dioxide in seawater by capillary isotachoelectrophoresis following isolation of the carbon dioxide by membrane permeation. 

One of the best-known commercial instruments developed for organic carbon determinations is the Beckman total carbon analyser, which utilises an analysis scheme developed by Van Hall and co-workers [57,99]. This instrument works reasonably well in fresh water. It has become a standard instrument in pollution control and water treatment [103]. The Beckman instrument has not worked as satisfactorily for seawater because of the latter s high carbonate and low organic content. 

Weliky et al. [154] described a procedure for the determination of both organic and inorganic carbon in a single sample of a marine deposit. Carbonate carbon is determined from the carbon dioxide evolved by treatment of the sample with phosphoric acid the residue is then treated with a concentrated solution of dichromate and sulfuric acid to release carbon dioxide from the organic matter. The carbon dioxide produced at the two stages of the analysis is estimated using a carb on analyser based on the thermal conductivity principle. In addition, total carbon content is determined on another subsample using the dry combustion furnace. This provides a check on the values determined by the phosphoric acid dichromate technique. 

Total and soil organic carbon, and total sulfur determinations of soils... 

ISO, 1995. Soil quality - Determination of organic and total carbon after dry combustion. ISO standard 10694 1995. 

Ratio of microbial biomass to total organic carbon Calculation from individual measures Indicates enrichment of microbial biomass relative to total organic carbon determined in nonstandard laboratory with specialized equipment Rice et al. (1996)... 

The DC 180 will calculate total organic carbon based on purgeable organic carbon and non-purgeable organic carbon results and include it in the report. Alternatively, total organic carbon may be determined as the difference of total carbon less inorganic carbon. 

Dalai [16] has described a wet digestion procedure for the determination of total carbon in soils. The digestion apparatus consisted of a McCartney... 

Various techniques have been used for the determination of organic (and total) carbon in sediments. These include both wet and dry combustion methods which depend on the quantitative conversion of the organic (or total) carbon to carbon dioxide [30-32], In addition, an approximate assay technique reported by Bremner and Jenkinson has been used [36]. 

The ability to measure the isotopic composition of individual compounds can be used to determinate whether or not some contaminants are being affected by surface/subsurface processes. In comparison, monitoring the isotopic composition of total carbon can only provide information concerning the processes affecting the contaminant mixture as a whole rather than individual compounds. 

Patterson, R. K. Automated Pregl-Dumas technique for determining total carbon, hydrogen, and nitrogen in atmospheric aerosols. Anal. Chem. 45 605-609, 1973. 

Analytical Methods. It was found that the concentration of both polymers could be analyzed by determining the total carbon in solution with a carbon dioxide coulometer, Coulometrics, Inc., Wheat Ridge, CO. The accuracy of this method is not good in the low polymer concentration range, that is less than 10-15 ppm. 

This is the case generally encountered in geochemical investigations a deep water is sampled and total carbonates and pH are determined to solve the question of whether or not the sampled water was in equilibrium with calcite (or other carbonates) at the T and P of sampling. The system is clearly determined the equilibria to be considered in this case are those of equations 8.73, 8.74, and 8.77 (eq. 8.76, 8.80, and 8.81 have no influence). 

The range of applicability of equation 11.122 depends on the limits of detection of in the sample. The current maximum age attained by direct radioactivity counting is about 4 X 10" a. To measure residual radioactivity, the total carbon in the sample is usually converted to CO2 and counted in the gas phase, either as purified CO2 or after further conversion to C2H2 or CH4. To enhance the amount of counted carbon, with the same detection limit (about 0.1 dpm/g), counters attain volumes of several liters and operate at several bars. More recent methods of direct detection (selective laser excitation Van de Graaif or cyclotron acceleration) has practically doubled the range of determinable ages (Muller, 1979). 

Plmenta, J.A. Wood, G.R. "Determination of free and total carbon in suspended air particulate matter collected on glass fiber filters". Environ. Sci. Technol., 1980, 14, 556-561. 

Filter substrates were chosen that were suited for subsequent determinations of aerosol mass, total carbon, elemental carbon, trace metals and aerosol light absorption coefficient The three filter assemblies contained, a 47 mm Pallflex Tissuquartz filter (2500 QAO), a 47 mm Nuclepore polycarbonate filter (0.40 ym pore size) and a 13 mm Pallflex Tissuquartz filter (2500 QAO). 

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