Solvent extraction test methods

Detection and measurement of ionizable surface contaminants by resistivity of solvent extract (ROSE), Method 2.3.25. IPC-TM-650 Test Methods Manual. Feb. 2001. 

The binder extraction method is the most common and widely used method for determining the binder content in the mixture. It uses hydrocarbon solvents capable of dissolving bitumen and a binder extraction apparatus. Because of the high purchase and disposal costs of solvents, the risk to the operator s personal health and safety and the environmentally unfriendly nature of the hydrocarbon solvents, this test method was started to be replaced with the ignition method. The binder extraction method by European standards is conducted in accordance with CEN EN 12697-1 (2012), whereas that by American standards is in accordance with ASTM D 2172 (2011) or AASHTO T 164 (2013) and AASHTO T 319 (2008). A detailed description of the binder extraction test method is given in Section 9.6.1. 

Analytical and test methods for the characterization of polyethylene and PP are also used for PB, PMP, and polymers of other higher a-olefins. The C-nmr method as well as k and Raman spectroscopic methods are all used to study the chemical stmcture and stereoregularity of polyolefin resins. In industry, polyolefin stereoregularity is usually estimated by the solvent—extraction method similar to that used for isotactic PP. Intrinsic viscosity measurements of dilute solutions in decahn and tetraHn at elevated temperatures can provide the basis for the molecular weight estimation of PB and PMP with the Mark-Houwiok equation, [rj] = KM. The constants K and d for several polyolefins are given in Table 8. 

Separation techniques may have to be applied if the given sample contains substances which act as interferences (Section 21.10), or, as explained above, if the concentration of the element to be determined in the test solution is too low to give satisfactory absorbance readings. As already indicated (Section 21.10), the separation methods most commonly used in conjunction with flame spectrophotometric methods are solvent extraction (see Chapter 6) and ion exchange (Chapter 7). When a solvent extraction method is used, it may happen that the element to be determined is extracted into an organic solvent, and as discussed above it may be possible to use this solution directly for the flame photometric measurement. 

On the other hand, single-residue methods developed by the applicants give basic information about appropriate cleanup steps and specific determination procedures. In addition, not many laboratories other than those from the applicants are able to test the real solvent extraction efficiency. The reason is that extraction studies need radio-labeled incurred residues instead of fortified samples. Hence enforcement methods provided by the manufacturers accelerate the development of methods which meet the needs of (official) food control laboratories. 

An important QC analysis in the fibre and textile industry is the surface finish determination by Soxhlet extraction (AATCC Test Method 94-1992). Solvent extraction is used on textile materials to determine naturally occurring oily and waxy materials that have not been completely removed from the fibres (ASTM Method D 2257-96). Meanwhile, environmental, safety... 

The overall method includes sample collection and storage, extraction, and analysis steps. Sampling strategy is an important step in the overall process. Care must be taken to assure that the samples collected are representative of the environmental medium and that they are collected without contamination. There is an extensive list of test methods for water analysis (Tables 8.2, 8.3, and 8.4), which includes numerous modifications of the original methods, but most involve alternative extraction methods developed to improve overall method performance for the analysis. Solvent extraction methods with hexane are also in use. 

In the test method (ASTM D4930), a weighed dry representative coke sample 6.3 mm in maximum size is extracted using methylene chloride in a Soxhlet apparatus. The mass of the residue remaining after extraction and evaporation of the solvent is the mass of the dnst control material. This test method is limited to those materials that are solnble in a solvent (e.g., methylene chloride) that can be used in a Soxhlet extraction type of apparatns. Tolnene and methyl chloroform have also been found to give resnlts eqnal to those of methylene chloride. 

Propellants, Solid Sampling, Examination and Testing", MIL-STD-286B, 30 June 1971, Method 104.1.3 "Solvent Extractive Method"... 

Test 6. Increase in Weight Method, This Method 201.3-3 of MIL-STD-286A (Ref 25) is used for detg the DPhA content of newly manufd propints, where the solvent extract contains no other brominatable material. It was not described in Ref 14... 

Solutions must be concentrated or the constituents must be isolated before trace amounts of the various organics present as complex mixtures in environmental water samples can be chemically analyzed or tested for toxicity. A major objective is to concentrate or isolate the constituents with minimum chemical alteration to optimize the generation of useful information. Factors to be considered in selecting a concentration technique include the nature of the constituents (e.g., volatile, nonvolatile), volume of the sample, and analytical or test system to be used. The principal methods currently in use involve (1) concentration processes to remove water from the samples (e.g., lyophilization, vacuum distillation, and passage through a membrane) and (2) isolation processes to separate the chemicals from the water (e.g., solvent extraction and resin adsorption). Selected methods are reviewed and evaluated. 

In either approach, the selection of isolation (e.g., solvent extraction, adsorption on carbon and synthetic resins) and concentration (e.g., lyophilization, vacuum distillation, reverse osmosis, ultrafiltration) methods is of paramount importance in properly assessing the potential toxicity of waterborne organics. A comprehensive literature review on the development and application of these and other methods to biological testing has recently been published by Jolley (3). 

Batch solvent extraction methods (e.g., by separatory funnel) for the preparation of extracts for biological analysis have a number of major problems. A large volume of solvent must be evaporated after the extraction step in order to obtain a sample sufficiently concentrated to be useful for biological testing. Artifacts can occur from solvent impurities, and reactions can occur during the evaporation process. 

Procedures for the determination of 11 elements in coal—Sb, As, Br, Cd, Cs, Ga, Hg, Rb, Se, U, and Zn—by neutron activation analysis with radiochemical separation are summarized. Separation techniques include direct combustion, distillation, precipitation, ion exchange, and solvent extraction. The evaluation of the radiochemical neutron activation analysis for the determination of mercury in coal used by the Bureau of Mines in its mercury round-robin program is discussed. Neutron activation analysis has played an important role in recent programs to evaluate and test analysis methods and to develop standards for trace elements in coal carried out by the National Bureau of Standards and the Environmental Protection Agency. 

For the purposes of this chapter, the solvent extraction of coal is limited to those investigations and test methods that are separate form the high-temperature treatment of coal with solvents in which the production of liquid products (liquefaction) is the goal. 

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