Acid digestion bomb

Inorganic and organic materials can be dissolved rapidly in Parr acid digestion bombs with Teflon liners and using strong mineral acids, usually nitric and/or aqua regia and, occasionally, hydrofluoric acid. Perchloric acid must not be used in these bombs due to the high risk of explosion. 

Decomposition in closed Teflon vessels at high pressure (up to 85 bar) with microwave heating. (Microwave Acid Digestion Bomb, Parr Instrument Company, USA.)... 

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. 

Hydrothermal synthesis does not require the water to be above its critical point. Huan, et al. published a synthesis of VOC6H5PO3XH2O prepared from phenylphosphonic acid, CeH5PO(OH)2 and vanadium(III) oxide, V2O3 (Huan et al., 1990). The two reagents were added to water, sealed in a Teflon acid digestion bomb, and heated to 200°C. Pure water has a vapor pressure of 225 PSI at 200°C, well within the bursting pressure of the bomb (1800 PSI). Unlike the quartz example, in this case, the solvent became incorporated into the final product. 

Uhrberg, R. Acid digestion bomb for biological samples. Anal. Chem. 54,1906-1908 (1982)... 

Nicholson, J.R.P., Savory, M.G., Savory, J., Wills, M.R. Micro-quantity tissue digestion for metal measurements by use of a microwave acid-digestion bomb. Clin. Chem. 35, 488 90 (1989)... 

Fish (total) Digestion of samples with nitric acid in a microwave acid digestion bomb, reduction to elemental mercury CVAAS 0.195 ng/mL >95 Navarro et al. 1992... 

The selectivity and sensitivity offered by atomic spectroscopy techniques can be used for direct and indirect determination of metals in a range of pharmaceutical preparations and compounds. Metals can be present in pharmaceutical preparations as a main ingredient, impurities, or as preservatives which can be prepared for analysis using non-destructive (direct or solvent dilution) or destructive methods (microwave acid digestion, bomb combustion, extraction, etc.) and the metal of interest measured against standards of the metal prepared in the same solvents as the sample. Methods associated with some pharmaceutical products are already described in the international pharmacopoeias and must be used in order to comply with regulations associated with these products, e.g titration techniques are carried out according to methods that are the same for all pharmaceutical products. 

Parr Bombs. Two types of Parr bombs were used. The acid digestion bombs were used for the ash dissolutions. About 0.2 g of shale or ash was dissolved in 3 mL aqua regia and 2 mL HF in the acid digestion bomb and heated at 110°C in an air-oven for two hours. After the dissolution, 1 g of boric acid was added to each sample solution, which was heated on a water-bath... 

Parr Bomb Dissolution of Shales. Originally the acid digestion bomb was developed by Bernas (14) for the dissolution of silicate matrices. An adaptation of this bomb is now marketed by Parr Instrument Company of Moline, Illinois. The dissolution procedure has been adapted to shales and was described in the Experimental Section. 

The results of using the acid digestion bomb for shales are included in Table IV. These three shales are distributed by the U.S. Geological Survey as "standard" shales Green... 

Table IV. Analysis of Oil Shales By Acid Digestion Bomb Dissolution and ICPES...

Model 4745 acid digestion bomb, Parr Instrument Co., 211 Fifty-Third... 

The use of a hydrothermal bomb for preparation of a metal organic framework is a well-known technique in inorganic chemistry [31], However, the use of a hydro-thermal bomb for the preparation of scaffold is very rare. The final mixmre with the appropriate composition for scaffold preparation is sealed in a PTFE-lined acid digestion bomb and heated at 40°C for 8 h under autogeneous pressure. After that, the bomb is kept at room temperature to cool the product, which is then frozen at —20°C, Finally, the product is vacuum dried to obtain the desired scaffolds [32-34] (Dutta PK et al, unpublished results). 

For the decomposition of inorganic samples by soda ash in platinum crucibles, the resistance of platinum is increased in an atmosphere of carbon dioxide. In a nitrogen atmosphere, platinum is corroded less by alkali metals. Peroxide bombs are good for wet ashing to destroy the organic matter in samples like coal. The PTFE acid digestion bomb prevents contamination and insures no losses by volatilization. Samples like coal can be analyzed in quantities of 50 mg or less. 

The acid digestion bomb is another powerful technique for solubilization of plastic samples, in which the digestive process is carried out in a sealed pressurized vessel called a digestion bomb and heated in a muffle furnace. The advantage of this approach is that the temperature of the process may reach well above the boiling point of the mixtures in the normal process, thus making possible the complete solubilization of some slow or incompletely dissolving components under open-vessel conditions. Volatilization of some of the analytes as well as sample contamination from airborne particulates can be also minimized. 

This approach has, however, certain limitation in terms of the amount of organic sample (most plastics materials) which can be digested while avoiding significant pressure buildup. Acid digestion bomb loading limits for some typical bomb sizes are shown in Table 11. 

Nitric acid is the preferred medium for acid bomb digestion. Special care must be exercised when a mix with sulfuric acid is to be applied, to avoid violent reactions with the samples. Operating limits on most acid digestion bombs are usually set at around 250°C and 1800 psi. Perchloric... 

Table 11 Recommended Loading Limits for Acid Digestion Bombs... 

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