Bomb method

Bomb Method the sample is burned in a bomb under oxygen pressures of 30 bar. The sulfur contained in the wash water is analyzed via gravimetry as barium sulfate. 

In the standard method, the metal enclosure (called the air chamber) used to hold the hydrocarbon vapors is immersed in water before the test, then drained but not dried. This mode of operation, often designated as the wet bomb" is stipulated for all materials that are exclusively petroleum. But if the fuels contain alcohols or other organic products soluble in water, the apparatus must be dried in order that the vapors are not absorbed by the water on the walls. This technique is called the dry bomb" it results in RVP values higher by about 100 mbar for some oxygenated motor fuels. When examining the numerical results, it is thus important to know the technique employed. In any case, the dry bomb method is preferred. 

Two simple methods for the semi-micro estimation of halogens are available, (a) the Carius method, and (b) the Parr bomb method. It should be emphasised that there are other methods available for these estimations on the true micro scale, but they do not lend themselves, by virtue of the balances, apparatus and manipulation required, to semi-micro work, or to the intermittent usage which class-work necessarily entails. 

In general, one day of oven aging at 70°C corresponds to one year of natural or shelf aging (a minimum requirement for mbber products), whereas the oxygen and air bomb methods are more drastic. By varyiag the amounts and types or combiaations of antioxidants the relative effectiveness of these materials against normal oxygen deterioration can be determined. 

The demand for the determination proved so great that the method has been placed on a routine basis. One man can make 40 to 50 chlorine determinations on dry resins in an 8-hour day with a precision approaching that of the almost prohibitively time-consuming potassium fusion method. The Parr-bomb method permits about 40 analyses by two men in an 8-hour day, but precision suffers considerably when the work is done at this speed. 

Baker, R. D. "Preparation of Plutonium Metal by the Bomb Method," Los Alamos Scientific Laboratory, LA-473 (1946). 

There is general agreement that static-bomb combustion calorimetry is inherently unsatisfactory to determine enthalpies of formation of organolead compounds2,3. Unfortunately, as shown in Table 6 only three substances have been studied by the rotating-bomb method. The experimentally measured enthalpies of formation of the remaining compounds in Table 6 were determined by reaction-solution calorimetry and all rely on AH/(PbPh4, c). 

Aspila et al. [60] have described a semi-automated method for the determination of inorganic, organic and total phosphorus in river and lake sediments. Total phosphorus is extracted from sediments with 1M hydrochloric acid after ignition at a high temperature (550°C) (method 1) or by digestion with sulphuric acid-potassium persulphate at 135°C in a sealed PTFE-lined Parr bomb (method 2). 

Sediment sample Bomb method of extraction Method 1 Method II Extraction with Im HCI after ignition Method 1 Method II Extraction with 1 HCI before ignition, Method 1... 

Details of both these methods as used by us are given below in specimen analyses. With regard to the bomb method, the lead washer supplied by the manufacturers was useless the lead melted and disintegrated at the temperature of the reaction. Copper was also found to be attacked and was otherwise unsatisfactory. Gold, on the other hand, was found to be most suitable. It is soft, will withstand the required temperature without melting or disintegrating, and is not attacked by fluorine, fluoride or alkali. 

Standardization, of the sodium peroxide bomb method with pure fluoroacetamide... 

W. D. Good, D. W. Scott, G. Waddington. Combustion Calorimetry of Organic Fluorine Compounds by a Rotating-Bomb Method. J. Phys. Chem. 1956, 60, 1080-1089. 

A recent brief review showed the working principles of various automatic analyzers6. A modified account of N and O analysis will be presented here. Today there exist in the market instruments that perform organic elemental analyses in a few minutes. The ease and speed of such analyses enable the use of such instruments for routine analysis. Although some operational details vary from model to model and between one manufacturer and another, all these instruments can be considered as exalted versions of the classical Pregl determination of C and H by conversion to CO2 and H2O, together with Dumas method for N by conversion to N2, the calorimetric bomb method for S by conversion to SO2 and SO3 and Schultzes method for O by conversion to CO. This is combined with modern electronic control, effective catalysts and instrumental measuring methods such as IR detectors and GC analyzers. 

The bomb method is quite similar to the bubble method except that the constant volume condition causes a variation in pressure. One must, therefore, follow the pressure simultaneously with the flame front. 

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). 

Strauss, W A., and Edse, R., Burning Velocity Measurements by the Constant Pressure Bomb Method, 7 th Symposium (International) on Combustion, The Combustion Institute, Pittsburgh, 1958, pp. 377-385. 

S.R. Grobler, A.J. Louw, A new microwave acid digestion bomb method for the determination of total fluorine. Caries Res. 32 (1998) 378-384. 

Burning, Laminar, of Gases. Influence of pressure and temperature on the laminar burning velocity of stoichiometric acetylene-air mixtures using a constant-volume bomb method is described by M.L. Agrawal S.P. Sharma in UnivRoorkeeResJ(India), 8(3-4), Part 11, 81-102(1965) (in Engl)... 

Fume Characteristics. In commercial blasting, one needs to know what poisonous gases condensed pro diets may be produced and in what proportions they may be found in the atmosphere following a blast. The poisonous gases are referred to in the expl industry as fumes. Limitations of the various methods used to measure fumes (Bichel gauge, Craw-shaw gage Trauzl block) have been recognized for years. The LTSBurMines classification of permissibles into Class A Class B is based on a closed-bomb method... 

Power. The pressure bomb method gave ca 110%TNT(Ref 14, p 132), while the Trauzl testjFr modif,gave a value(called CUP)equal to 2%PA(Ref 16). Blatt(Ref 22) gives Trauzl test value 98% TNT... 

Microwave assisted wet digestion has attracted considerable attention and has been successfully applied to plant material. Both open and closed vessels have been used, but the most popular approach is the sealed bomb method (Kingston and Jassie, 1988 Sulcek and Povondra, 1989 Matusiewicz, 1991). Karanassios et al. (1991) describe microwave stopped flow digestion systems that can give rapid (ie, less than 5 min) reproducible extractions of elements of environmental concern from plant samples. 

G.Seitz, Explosivst 1955, 173-78 201-06 (Investigation of burning of proplnts in a closed bomb) 50)H.I.Lewis, PicArsnSFAL Rept 424 (1956) (Instrumentation for closed bomb method of proplnt testing 5 l)A.I.Rubin, PATR 2237 (1956) (Computing linear burning rate of proplnts from closed bomb data by means of analog computer) 52)M.Weinstein... 

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