Elemental analyzer combustion

Elemental analysis of the oils was carried out as follows carbon and hydrogen by micro combustion using a Perkin-Elmer 240 Elemental Analyzer sulphur by X-ray fluorescence using a Telsec Lab X-100 apparatus nitrogen by chemiluminescence using a Dohrmann DN-10 apparatus. 

CF-IRMS provides reliable data on micromoles or even nanomoles of sample without the need for cryogenic concentration because more of the sample enters the ion source than in DI-IRMS. CF-IRMS instruments accept solid, liquid, or gaseous samples such as leaves, soil, algae, or soil gas, and process 100-125 samples per day. Automated sample preparation and analysis takes 3-10 min per sample. The performance of CF-IRMS systems is largely determined by the sample preparation technology. A variety of inlet and preparation systems is available, including GC combustion (GC/C), elemental analyzer, trace gas pre-concentrator and other. The novel... 

The development of this technique has proceeded along several independent paths with two principal lines being elemental analyzer-IRMS and capillary gas chromatography-IRMS. In elemental analyzers, samples are combusted to CO2, N2, SO2, and H2O, which are either chemically trapped or separated on GC columns. The advantages of these techniques are an automated preparation with low costs per sample and a large sample through-put. 

Commercial combustion elemental analyzers perform a flash combustion, converting samples to CO2, H2O, N2, and SO2 simultaneously. These different gases are then chemically trapped, converted, or separated on GC columns and measured in a continuous flow mass spectrometer. This technique allows the determination... 

For the extraction of sulfates and total sulfur a suitable acid and reducing agent, such as tin(II)-phosphoric acid (the Kiba solution of Sasaki et al. 1979) is needed. The direct thermal reduction of sulfate to SO2 has been described by Holt and Engelkemeier (1970) and Coleman and Moore (1978). Ueda and Sakai (1984) described a method in which sulfate and sulfide disseminated in rocks are converted to SO2 and H2S simultaneously, but analyzed separately. With the introduction of on-line combustion methods (Giesemann et al. 1994), multistep off-line preparations can be reduced to one single preparation step, namely the combustion in an elemental analyzer. Sample preparations have become less dependent on possibly fractionating wet-chemical extraction steps and less time-consuming. 

Figure 27-6 Gas chromatographic trace from elemental analyzer, showing substantially complete separation of combustion products. The area of each peak (when they are not off scale) is proportional to the mass of each product- [From Pella. -Elemental Organic Analysis. 2. Slate of the Art "Am. Lab August 1990, p. 28.)...

Write a balanced equation for the combustion of C8H7N02SBrCl in a C,H,N,S elemental analyzer. 

Elemental analyses. Elemental (C,H,N, and 0) analyses of the kerogen isolates, and analyses of the total carbon content of the whole shale were obtained, directly, using a Carlo Erba Model 1106 Elemental Analyzer(any use of trade names in this publication are for descriptive purposes only and does not constitute indorsement by the U. S. Geological Survey. Elemental analyses (C,H, and N) of the coal samples were accomplished using a Perkin-Elmer Model 240 Elemental Analyzer, with oxygen contents calculated by difference. The ash content of the whole shale was determined by combustion of 10-20 mg aliquots in a muffle furnace at 750°C. All samples (coal and kerogen) were... 

Elemental analyzer An instrument that uses high-temperature combustion, typically 800-1000 °C, to convert the carbon, hydrogen, nitrogen, and sulfur constituents of a substance into gases that can be separated and measured. Some instruments can also measure oxygen contents of samples. 

Total carbon The sum of inorganic and organic carbon in sediment that can be measured by combustion at 800-1000 °C with an elemental analyzer. 

Organic matter content was estimated by combustion of the samples on an elemental analyzer (EA-IRMS) coupled to a DeltaPlus-XL Finnigan mass-spectrometer. None of the samples contained more Aan 0.2% organic carbon. 

FIGURE 15.7 Schematic showing a flash combustion EA in series with an interface and IRMS for the analysis of bulk nitrogen and carbon isotope values (based on a ThermoFinnigan Flash Elemental Analyzer [31]). Reprinted from Benson, S., Fennard, C, Maynard, R, Roux, C. (2006) Forensic applications of isotope ratio mass spectrometry—a review. Forensic Sci. Int., 157(1), 1-22, with permission from Elsevier [1]. 

Elemental analyzers are widely used to determine the elemental composition or the empirical formula of materials, especially organic compounds. In this method, the compound (e.g., polymer) is combusted with excess oxygen in a controlled environment, and various traps collect the gases formed including carbon dioxide, water, nitric oxide and sulfur dioxide. By analyzing the quantity of all trapped gases, the mole ratios of C, H, N and S are determined. 

FIGURE 2 Schematic diagram of the combustion train in the Perkin-Elmer 240C Elemental Analyzer. [Courtesy of Perkin-Elmer Corporation.]... 

The elemental analyzer measures the C, H and N content of biomass upon its combustion at 925°C in a pure oxygen environment by monitoring the volatile compounds (C in CO2, N in N2, H in H2O). The results are reproducible but largely dependent on the growth conditions the solid residue of combustion is ash and contains oxides and salts. Mass fractions of biomass can be expressed as ... 

Compounds that do not decompose cleanly into their elements must be analyzed by other means. Combustion analysis is particularly useful for determining the empirical formulas of carbon-containing compounds. In combustion analysis, an accurately known mass of a compound is burned in a stream of oxygen gas. The conditions are carefully controlled so that all of the carbon in the sample is converted to carbon dioxide, and all of the hydrogen is converted to water. Certain other elements present in the sample are also converted to their oxides. 

The bomb method for sulfur determination (ASTM D129) uses sample combustion in oxygen and conversion of the sulfur to barium sulfate, which is determined by mass. This method is suitable for samples containing 0.1 to 5.0% w/w sulfur and can be used for most low-volatility petroleum products. Elements that produce residues insoluble in hydrochloric acid interfere with this method this includes aluminum, calcium, iron, lead, and silicon, plus minerals such as asbestos, mica, and silica, and an alternative method (ASTM D1552) is preferred. This method describes three procedures the sample is first pyrolyzed in either an induction furnace or a resistance furnace the sulfur is then converted to sulfur dioxide, and the sulfur dioxide is either titrated with potassium iodate-starch reagent or is analyzed by infrared spectroscopy. This method is generally suitable for samples containing from 0.06 to 8.0% w/w sulfur that distill at temperatures above 177°C (351°F). 

The catalysts with metals are previously impregnated with solutions of vanadyl and nickel naphtenates based on the Mitchell method [4], Before hydrothermal deactivation the samples were calcined in air at 600°C. The activity was performed in the conventional MAT test using 5 grams of catalyst, ratio cat/oil 5, stripping time 35 seconds, and reaction temperature 515°C. Elemental analyses to determine the total amount of carbon in the spent catalysts were done by the combustion method using a LECO analyzer. 

Elemental composition H 1.56%, Te 98.44%. The gas is identified by its physical properties and measured by chemical analysis. Two most confirmatory methods recommended here are (1) GC/MS, the characteristic mass ions should be in the range 126 to 132, and (2) furnace-AA or ICP emission spectroscopic analysis for metalic tellurium. For the AA analysis, hydrogen telluride gas should be passed through water and the solution acidified and analyzed for tellurim. Hydrogen may be measured by the classical combustion method involving oxidation to form water, followed by gravimetry. 

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