Oxygen bomb method

Several test methods are available for determining sulfur in diverse petroleum product and lubricant matrixes from sub-mg/kg to m% concentration levels. One of the earliest methods issued by the D02 committee was for the sulfur determination by an oxygen bomb method (D 129) first issued in 1922. This was the 15 standard ever issued by the D02 Committee. The techniques currently used for the sulfur determination include classical wet chemistry (D 129, D 1266, D 1552, and D 2784), X-ray fluorescence (D 2622, D 4294, D 4927, D 6334, D 6443, D 6445, and D 7039), atomic spectroscopy (D 4951 and D 5185), and various thermal combustion microelemental methods using various detection techniques such as microcoulometry (D 3120 and D 3246), UV-fluorescence (D 5453 and D 6667), electrochemistry (D 4045 and D 6920), GC-FPD (D 7041), etc. A list of such available test methods is given in Table 4 along with other pertinent details as to the applicability of the method. 

ASTM D942 Oxidation stability of lubricating by the oxygen bomb method (20)... 

Predisposition (stability) to oxidation can be estimated for fats by the active oxygen method (AOM), and for fat-containing products by the Schall oven test and the oxygen bomb method and as a function of oxygen absorption. 

Sulfur Tests. The sulfur (D90) content of gasoline and burning oils is an important specification. About 10 g of oil is burned in a small lamp, and the products of combustion are drawn through a sodium carbonate absorption solution. The sulfur is determined by titrating the unused sodium carbonate solution. Sulfur in readual fuel oil and cirade oil is determined by the ordinary oxygen-bomb method (D129). 

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. 

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. 

A PET oligomer isolation method has utilised chloroform extraction in a Parr bomb lined with a Teflon-TFE fluoro-carbon resin [40]. The analytics of fluoropolymer processing aids (combustion analysis, XRF, EUR, 19F NMR, OM) have recently been described [29]. Combustion analysis (Parr Oxygen Bomb Calorimeter) can be used for quantitative analysis... 

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). 

In addition to the analysis of the thermal stability of the perchloric acid organic reaction media mixtures, a procedure was worked out to determine the fate of the perchloric acid by chlorine analysis of the batch, effluent streams, etc. Preliminary analyses on selected process samples showed no tendency for perchloric acid to concentrate in recycle material and therefore build up in the reactor. A total of less than 1% of the initial charge of perchloric acid (total chlorides calculated as perchloric acid) was found in the combined recovered acid-ester and olefin fractions. Less than 1 % of the initial charge of perchloric acid was found in the finished ester. The analytical method used was an oxygen bomb decomposition, followed by titration of chlorides with 0.0liV silver nitrate, using a recording automatic titrator. The eventual fate of the perchloric acid catalyst was... 

The Determination of Selenium. The most difficult trace element to determine in coal by wet chemical methods is selenium. Two alternative dissolution techniques can be used—H. L. Rooks combustion method (7) and the oxygen bomb combustion method (4). Also, two alternative analytical methods can be used—the hydride evolution method (5) and the graphite furnace method. 

The American Society for Testing and Materials (ASTM) has developed a series or standard test methods for both solid and liquid fuels in oxygen bomb calorimeters. Advanced combustion calorimeters are capable of performing 8 to 10 tests per hour with a precision of 0.1%. 

Other accelerated methods for measuring lipid oxidation include the oxygen bomb test and the Schaal oven test. These methods are described by Wan (1995). 

The first method (ASTM D-2361) offers a choice of two procedures for combusting the coal sample. In the bomb combustion procedure, the oxygen bomb used is the same as, or very similar to, that used in determination of the calorific value (ASTM D-2015 ASTM D-3286). 

In second test method (ASTM D-4208), 1 g of the analysis sample of coal is placed in a crucible inside an oxygen bomb. A sodium carbonate solution... 

A modification of the oxygen bomb combustion method (ASTM D-2361) for the determination of chlorine consisted of acidifying a solution of the adsorbed combustion products and titrating the chlorine potentiometrically. A potentio-metric titration was also tried for the determination of chlorine by the oxygen flask method. Combustion products, including chlorine, were absorbed in sodium hydroxide (NaOH), and the chloride was measured using silver-silver chloride electrodes. Although there was no statistical difference in results obtained from potentiometric titration and the Eschka procedure, the latter was more precise. 

ASTM D-3684. Standard Test Method for Total Mercury in Coal by the Oxygen Bomb Combustion/Atomic Absorption Method. 

The common method of determining the gross calorific value of coal is with either an adiabatic calorimeter (ASTM D-2015 this test method was discontinued without replacement in 2000 but is still in use in many laboratories) or an isothermal bomb calorimeter (ASTM D-3286). In these methods, a weighed sample is burned in an oxygen bomb covered with water in a container surrounded by a jacket. 

The thermal combustion properties measured in the test are related to the flammability characteristics of the material.5155 For example, the heat release temperature from method A approximates the surface temperature at ignition (Section 14.3.2.1). The net calorific value from method B approximates the net heat of combustion measured in an oxygen bomb calorimeter. 

Oxygen Bomb Calorimetry and Combustion Methods, Tech, manual 130, Parr Instrument Co., Moline, IL. 

The first step in analysing plastics for metals content in polymers by ICP-AES technique is that they must be prepared in solutions that are suitable for nebulization. There are four general methods applicable for sample preparation for metal analysis by ICP-AES and they are solvent dissolution of some plastics dry ashing using a muffle furnace acid digestion using a microwave oven and oxygen bomb combustion. 

Sample Preparation Using Oxygen Bomb Combustion Method... 

---