Oil concentration analysis

Benchtop X-ray energy dispersive analyzer BRA-17-02 based on a gas-filled electroluminescent detector with an x-ray tube excitation and range of the elements to be determined from K (Z=19) to U (Z=92) an electroluminescent detector ensures two times better resolution compared with traditional proportional counters and possesses 20 times greater x-ray efficiency compared with semiconductor detectors. The device is used usually for grits concentration determination when analysing of aviation oils (certified analysis procedures are available) and in mining industry. 

The insecticide aminocarb has also been used extensively in eastern Canada on budworm control operations. Fenitrothion has been applied as a water emulsion (New Brunswick) and an oil solution (Quebec), but aminocarb because of its formulation characteristics, has been only applied operationally as an oil solution. Analysis of spruce foliage (7) showed aminocarb had a half life of 5 to 6 days with complete disappearance by 64 days post spray. Subsequent work (8) confirmed the short half life of aminocarb on coniferous foliage (3.2 to 6.9 days), and showed that the half life was dependant on the initial concentration of the insecticide. The material was found to be highly labile and dissipated rapidly and the authors made the statement that with these characteristics... 

In a closed system equipped with an oil bubbler, 30 ml of tetrahydrofuran were added to a mixture of 4-amino-5-chloro-2-methoxybenzoic acid, 2.02 g (0.010 mole) and l,l -carbonyldiimidazole, 1.62 g (0.010 mole) with stirring. When evolution of carbon dioxide ceased, nitrogen was bubbled through the reaction mixture for 1 hr. A solution of 3-aminoquinuclidine, 1.26 g (0.010 mole) in 10 ml tetrahydrofuran was added dropwise to the stirred reaction mixture and stirring at room temperature continued for 3 hrs. TLC analysis (3% cone, ammonium hydroxide solution in methanol) showed some product formation. The mixture was heated at reflux temperature for 18 hours and then concentraded to an oil. TLC analysis showed the presence of the product, imidazole and 3-aminoquinuclidine. The oil was dissolved in methylene chloride (75 ml) and washed twice with 50 ml portions of aqueous sodium bicarbonate solution. The methylene chloride layer was dried over anhydrous magnesium sulfate and concentrated to yield 2.0 g (67%) of a glassy amorphous solid, the free base of the title compound. 

The product from Step 1 was dissolved in 50 ml toluene, tri-n-butyltin-hydride (9.7 mmol) added followed by azobisisobutyronitrile (30 mg). The mixture was heated to 95 °C 5 hours, cooled, concentrated, purified by chromatography on silica gel using EtOAc/hexane, (1 1), and the product isolated in 60.8% yield as an oil. Elemental analysis data supplied. 

The product from Step 2 (0.38 mmol) was dissolved in 15 ml chloroform at ambient temperature and 0.1 M iodine dissolved in chloroform added dropwise until a brown color persisted. Thereafter, the reaction was stirred 24 hours and then quenched with 2 ml 1 M KF dissolved in methyl alcohol and 2 ml 5% aqueous sodium bisulfite. The layers were separated, the aqueous layer extracted 3 times with 20 ml chloroform, washed, dried, concentrated, and the product isolated in 84.3% yield as a slightly yellow oil. Elemental analysis data supplied. 

The emulsion water concentration has a double effect on pumping costs. For a fixed fiow rate of crude oil, as the water content increases, the total volume fiowing increases, which increases the cost of pumping. However, additional water in the emulsion also reduces its viscosity and thereby lowers pumping costs. These two factors tend to offset each other for emulsion crude-oil concentrations in the 50-70% range. At higher oil concentrations, the viscosity increases more rapidly, and this situation reduces the incentive for further water reductions. Correlations of emulsion viscosity as a function of water concentration, such as were described earlier, are required to perform this analysis. Calculations were performed for a hypothetical pipeline system with the following characteristics ... 

The results of this analysis are shown in Figure 5. The emulsion pumping cost is minimized for the hypothetical pipeline system at an emulsion crude-oil concentration in the 60-62% range, and the water-disposal costs naturally decrease continuously as emulsion water content is decreased. The total cost for this case reaches a minimum at about 76% crude oil in the emulsion. 

Analysis of systematic errors in the determination of hydrocarbons in water can be achieved by use of Youden plots after transformation of the results to an overall mean of Mtotal=0 and a standard deviation of Stotal=l (Fig. 3). Almost all laboratories are distributed around the 45° line indicating that most of the variation was systematic rather than random, particularly at higher mineral oil concentrations (sample pair S2/S4, Fig. 3B). Results located within the interval Mtotal 2 Stotal indicate sufficient proficiency of the participating laboratories in performing the determination of hydrocarbons in water... 

Whichever mefliod is selected, certain practical considerations are essential to making good measurements in food emulsions. The ulfrasonic properties of flie components in food emulsions are particularly sensi tive to temperature and therefore it is usually impor tant to control the measurement temperature carefully (i.e., 0.2 ms j or better). At approximately 18°C, coil = C water and so the ultrasonic technique becomes relatively insensitive to oil concentration (10). At higher and lower temperatures, ultrasonic measurements become increasingly independent on concentration because C qJi—C water I increases. It may, therefore, be pos sible to enhance the sensitivity of an ultrasonic analysis by carefully selecting the temperature at which the measurements are carried out. The attenuation coefficient is typically less dependent on temperature than is the ultrasonic velocity and may be a more reliable parameter to measure in situations when thermal control is poor (e.g., on-line measurements). 

Reproduced with permission from Wilson LA, Ding JH, and Woods AE (1991) Gas-chromatographic determination and pattern-recognition analysis of methanol and fusel oil concentrations in whiskeys. Journal of the Association of Official Analytical Chemists 74 248-256.)... 

ANFO is typically yellowish spheres that dissolve slowly in water. Suspected ANFO is treated with a volatile solvent such as chloroform and the filtrate concentrated by slow evaporation for analysis by gas chromatography (GC) to identify the fuel oil component. The solid residue is dried and tested for ammonium nitrate by either chemical spot tests or instrumental methods. If weighed prior to solvent extraction, reweighing of the residual ammonium nitrate will demonstrate that the oil concentration is in the proper range for ANFO-type explosives. 

Sebedio, J.-L. and De Rasilly, A. (1993) Analysis of cyclic fatty acids in fish oil concentrates, in Proceedings of the 17th Nordic Lipid Symposium, Imatra, Finland, pp. 212-16. 

It is essential that actual water test analysis data for dissolved and dispersed oil concentrations are needed in the planning stage prior to designing a water treating facility for a specific application. If the design engineer assumes a value for the dissolved oil content without first having obtained actual water test analysis for the specific... 

Any water analysis method is only as good as the "sample" used to represent the effluent stream. Sampling of a continuously flowing stream containing two or more phases (e.g., oil and water) is difficult unless the mixture is completely emulsified or is a very fine stable dispersion. Since the sampling techniques for oil concentration measurement and particle size distribution differ in some aspects, they are described separately here. 

An important application of this type of analysis is in the determination of the calculated cetane index. The procedure is as follows the cetane number is measured using the standard CFR engine method for a large number of gas oil samples covering a wide range of chemical compositions. It was shown that this measured number is a linear combination of chemical family concentrations as determined by the D 2425 method. An example of the correlation obtained is given in Figure 3.3. 

---