ASTM D5369 – 93 R98

Designation: D 5369 – 93 (Reapproved 1998) Standard Practice for Extraction of Solid Waste Samples for Chemical Analysis Using Soxhlet Extraction1 This standard is issued under the fixed designation D 5369; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval. 1. Scope 1.1 This practice describes standard procedures for extract- ing nonvolatile and semivolatile organic compounds from solids such as soils, sediments, sludges, and granular wastes using Soxhlet extraction. 1.1.1 The sample must be suitable for being mixed with the sample drying agent, sodium sulfate or magnesium sulfate, to provide drying of all sample surfaces. 1.2 This practice, when used in conjunction with Test Method D 5368 is applicable to the determination of the total solvent extractable content (TSEC) of a soil, sediment, sludge, or granular solid waste and depends upon the solvent chosen for extraction. 1.3 This practice is limited to solvents having boiling points below the boiling point of water at ambient pressure. 1.4 The solvent extract obtained by this practice may be analyzed for total or specific nonvolatile and semivolatile organic compounds but may require sample clean-up proce- dures prior to specific compound analysis. 1.4.1 This practice provides sample extracts suitable for analysis by various techniques such as gas chromatography with flame ionization detection (GC/FID) or gas chromatogra- phy with mass spectrometric detection (GC/MS). 1.5 This practice is recommended only for solid samples that can pass through a 10-mesh sieve (approximately 2-mm openings), or are less than 2 mm in thickness. 1.6 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appro- priate safety and health practices and determine the applica- bility of regulatory limitations prior to use. For specific precautions see Section 9. 2. Referenced Documents 2.1 ASTM Standards: D 75 Practices for Sampling Aggregates2 D 420 Practice for Investigating and Sampling Soil and Rock for Engineering Purposes3 D 2234 Test Method for Collection of a Gross Sample of Coal4 D 2910 Practice for Concentration and Recovery of Organic Matter from Water by Activated Carbon5 D 3086 Test Method for Organochlorine Pesticides in Wa- ter5 D 3694 Practices for Preparation of Sample Containers and for Preservation of Organic Constituents5 D 3975 Practice for Preparation of Samples for Collabora- tive Testing of Methods for Analysis of Sediments5 D 3976 Practice for Preparation of Sediment Samples for Chemical Analysis5 D 4281 Test Method for Oil and Grease (Fluorocarbon Extractable Substances) by Gravimetric Determination5 D 5368 Test Method for the Gravimetric Determination of Total Solvent Extractable Content (TSEC) of Solid Waste Samples6 E 122 Practice for Choice of Sample Size to Estimate a Measure of Quality for a Lot or Process7 2.2 EPA Document: SW 846 Method 3540 Soxhlet Extraction, Test Methods for Evaluating Solid Waste, Physical/Chemical Methods SW 846, Third Edition8 3. Terminology 3.1 Definitions: 3.1.1 GC—gas chromatography. 3.1.2 GC/MS—gas chromatography with mass spectromet- ric detection. 3.1.3 TSEC—total solvent extractable content. The total concentration by weight (w/w) of organic materials that are extractable from a soil or solid waste by the selected solvent. 4. Summary of Practice 4.1 The sample is mixed with sodium sulfate or magnesium sulfate, placed in an extraction thimble, and extracted using an appropriate solvent in a Soxhlet extractor for a 15 to 20-h period. For additional information, see Test Method D 4281. 1 This practice is under the jurisdiction of ASTM Committee D34 on Waste Management and is the direct responsibility of Subcommittee D34.01.06 on Analytical Methods. Current edition approved March 15, 1993. Published May 1993. 2 Annual Book of ASTM Standards, Vol 04.03. 3 Annual Book of ASTM Standards, Vol 04.08. 4 Annual Book of ASTM Standards, Vol 05.05. 5 Annual Book of ASTM Standards, Vol 11.02. 6 Annual Book of ASTM Standards, Vol 14.02. 7 Annual Book of ASTM Standards, Vol 11.04. 8 Available from the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402. 1 Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States. NOTICE: This standard has either been superceded and replaced by a new version or discontinued. Contact ASTM International (www.astm.org) for the latest information. The time required may be longer or shorter than the stated period, provided the extraction time selected has been demon- strated appropriate for the compounds and matrix of interest. 4.2 The solvent extract may be further processed using sample clean-up techniques and may be analyzed using instru- mental methods for specific nonvolatile or semivolatile organic compounds. This practice does not include sample extract clean-up methods. 5. Significance and Use 5.1 This practice provides a general procedure for the solvent extraction of organics from soils, sediments, sludges, and fine-grained solid wastes. It may be used as the initial step in the solvent extraction of organic constituents from waste materials for the purpose of quantifying extractable organic compounds. When the appropriate extraction solvent is used, the procedure can be applied to the determination of the total solvent extractable content (TSEC) of the sample. The extrac- tion of nonvolatile or semivolatile organic compounds from the above solid waste should use solvents listed in Table 1 or SW846 Method 3540. 5.2 The detection limit, linear concentration range, and sensitivity of the method for specific organic compound analysis will depend upon the method used for instrumental analysis and will also depend upon the sample clean-up and solvent concentration methods used. Typical detection limits that can be achieved for GC or GC/MS are in the parts per million and sub-parts per million range. 5.2.1 The method detection limit can be adjusted by varying the volume of extract used and by additional sample clean-up prior to analysis. 5.3 Soxhlet extraction has an advantage when analyzing solid waste and soil/waste mixtures which form emulsions with more rigorous solvent mixing extraction techniques. 6. Interferences 6.1 Solvents, reagents, glassware, and other sample process- ing hardware may yield discrete artifacts or elevated baselines which cause misinterpretation of follow-up analyses. All of these materials must be demonstrated to be free of interference under the conditions of the follow-up analysis. Specific selec- tion of reagents or the purification of solvents by distillation in all glass systems, or both, are required when organic compo- nent analysis follows extraction. 6.1.1 Glassware should be cleaned by washing with deter- gent or non-chromate cleaning solution, rinsing first with tap water, then reagent water, then redistilled acetone, and finally with pesticide quality solvent (that is, the solvent used for extraction). If the type and size of glassware permits, it may be cleaned by heating in a muffle furnace at 400°C for 15 to 30 min. Alternatively, glassware may be oven dried at 103°C for at least 1 h, after solvent rinsing and draining. Volumetric glassware should not be heated in a muffle furnace. 6.1.2 Plastics, except PTFE-fluorocarbon, can be a source of serious interference, especially when specific organic constitu- ents are of analytical interest. Their use must be avoided. Samples should be collected in glass bottles with PTFE- fluorocarbon-lined caps. Alternatively, caps may be lined with precleaned aluminum foil when the pH of the sample is near neutral and the salt content of the sample is low. To minimize the possibility of contamination of containers after cleaning, these items should be cleaned immediately prior to use and TABLE 1 Selected Applications of Soxhlet Extraction for Extraction of Organic Constituents from Solid Matrices Sample Matrix Solvent Compounds or Constituents Extraction Time, h(cycles) Reference (1) Sediment 1,1,1-trichloro-1,2,2-trifluoroethane (Freon) oil and grease 4 (80) (1)A Plumb (1983) (2) Sludges and similar materials 1,1,1-trichloro-1,2,2-trifluoroethane (Freon) oil and grease 4 (80) (2) Standard Methods (3) Sludges from sewage hexane then methanol total organic C oil, grease, fats 24 (3) Strachan (1983) (4) Municipal wastewater suspended solids and activated carbon hexane/dichloromethane semivolatile priority pollutants 24 (480) (4) Harrold (1982) (5) Soil and housedust acetone/hexane(1:1) organochlorine insecticides 5 (60) (5) EPA (1980) (6) Sediment dichloromethane phenols 8 (6) Goldberg (1980) (7) Soil a) acetone/n-hexane(1:1) aldrin, dieldrin 12 (554) (7) Chiba (1968) b) acetonitrile aldrin, dieldrin 14 (47) c) 2-propanol/n-hexane(1:1) aldrin, dieldrin 18 (108) (8) Soil chloroform/methanol(1:1) (other solvents also studied) dieldrin 8 (160) (8) Saha (1969) (9) Airborne particulates methanol (cyclohexane also studied) gross organics 2 (9) Hill (1977) (10) Airborne particulates benzene selected PAHs 4–6 (10) Pierce (1975) (11) Airborne particulates numerous solvents studied selected PAHs 6 (11) Stanley (1967) (12) Coke oven aerosol particulates benzene selected PAHs 2 (18–20) (12) Broddin (1977) (13) Artificial aerosol particulates methanol/benzene methanol/benzene methanol/benzene selected PAHs selected phthalates selected aliphatics 8 (80) 16 (160) 2 (20) (13) Cautreels (1976) methanol selected nitrogen aromatics 4 (40) benzene selected nitrogen aromatics 2 (20) (14) Activated carbon chloroform chloroform/ethanol phenols gross organics 44 (440) (14) Pahl (1973) (15) Buelow (1973) (15) Glass fiber filters 26 solvents and 24 binary mixtures total organic carbon 6 (16) Grosjean (1975) (16) Surface sediments methanol then dichloromethane total oil hydrocarbon 48 (160) (17) Sporstol (1985) (17) Bottom sediment hexane/acetone/isooctane chlorinated benzenes 18 (18) Onuska (1985) (18) Environmental particulates benzene chlorinated dioxins 16 (19) Lamparski (1980) (19) Soils hexane/acetone/methanol DDT 12 (20) Nash (1972) A The boldface numbers in parentheses refer to the list of references at the end of this practice. D 5369 2 NOTICE: This standard has either been superceded and replaced by a new version or discontinued. Contact ASTM International (www.astm.org) for the latest information. capped. A glassware rinse should be performed with the extraction solvent immediately prior to use. 6.2 A blank Soxhlet extraction and analysis should be performed in order to determine the solvent, drying agent, and apparatus background. If necessary, the glass (or paper) thimble and glass wool should be leached with solvent prior to use in order to minimize contamination. Method blanks should be less than 20 % of the concentration of the minimum needed reportable concentration. A method blank(s) must be reported with method data. 6.3 A relatively high TSEC background (>20 % of the minimum TSEC of interest) can result from solubility of sodium sulfate or other drying agent in the extraction solvent. This will preclude the application of the method for TSEC determinations. 6.4 Impurities in the extracting solvent can be a source of interference or TSEC background. Solvent blanks should be analyzed with each new bottle of solvent. Whenever a high TSEC background, or interfering compounds, are traced to the solvent, a new source of solvent should be obtained. Alterna- tively, impurities can often be removed by distillation in glass. 6.5 If organic compound interferences are found in the anhydrous sodium sulfate or magnesium sulfate, the drying agent may be rinsed with pure extraction solvent, or alterna- tively, Soxhlet extracted, followed by oven drying. 6.6 Inorganic constituents extractable from the waste by the extraction solvent will result in a positive interference in the determination of TSEC. This potential for interference must be determined by the analyst on a case-by-case basis. 6.7 When specific organic compound analysis is of interest, matrix interferences may be caused by compounds that are coextracted from the sample (but are not of interest). The extent of such matrix interferences will vary considerably depending on the sample and the specific instrumental analysis method used. Matrix interferences may be reduced by a judicious choice of extracting solvent, or alternatively, by using a clean-up technique on the extract following Soxhlet extrac- tion. 7. Selection of the Extraction Solvent 7.1 The selection of solvent for extraction will depend upon many factors, including the following (see Table 1 for selected applications): 7.1.1 Boiling point of the solvent. 7.1.2 Boiling point of the compounds or class of compounds of interest. 7.1.3 Tendency of the solvent and matrix to form emulsions. 7.1.4 Solvent strength (that is, polarity, solubility of com- pounds of interest). 7.1.5 Safety of solvent use (that is, toxicity, flammability). 7.1.6 Purity of solvent. 7.1.7 Solvent compatibility with analytical instrumentation. 7.2 The analyst should demonstrate a recovery using a spiking procedure in the matrix of interest before using this procedure. 7.3 Because the extraction is carried out at temperatures approaching the boiling point of the solvent for the entire extraction period, the analyst must ensure that heat-labile and more volatile solutes that may be of interest are stable and recoverable by the method. Low-boiling fractions can also be lost in the solvent evaporation steps where Kuderna-Danish solvent concentration is performed or where TSEC is deter- mined gravimetrically after solvent evaporation. 7.4 The rate and extraction efficiency of the Soxhlet extrac- tion process are not only a function of the solubility of the constituents of interest in solvent versus the matrix, but are also related to the dissolution process. This depends upon the ease of penetration of the solvent into the solid sample matrix. Fine particles are extracted more easily than large particles because of the increased surface area they provide. Therefore the particle nature of the sample must be evaluated and docu- mented. 7.5 In many cases where the extraction efficiency of the constituent of interest during the extraction period is less than 100 %, the efficiency of the solvent extraction process is highly dependent upon the control of conditions during the Soxhlet extraction process. Extraction efficiency will depend upon the combined effect of the specific solvent used, the temperature at which extraction occurs, the cycle time for the Soxhlet appa- ratus, and the total extraction time. Therefore the rate and duration of extraction must be closely controlled. 8. Apparatus 8.1 Soxhlet extraction apparatus consisting of Soxhlet ex- tractor, Allihn condenser, and 500-mL round-bottom boiling flask. 8.1.1 Allihn Condenser, bottom standard taper joint 45/50. 8.1.2 Boiling Flask, flat bottom, standard taper joint 24/40. 8.1.3 Soxhlet Extractor, 85-mL, top standard taper joint 45/50, bottom standard taper joint 24/40. 8.2 Glass or Paper Thimble or Glass Wool to retain sample in Soxhlet extraction device. It should drain freely and may require cleaning before use. To clean the thimbles, pre-extract them with the solvent to be used for sample extraction. 8.3 Boiling Chips, Glass Beads, or PTFE-fluorocarbon Boiling Stones, approximately 10/40 mesh. Boiling chips or glass beads can be cleaned by heating to 400°C for 30 min. Alternatively, Soxhlet extract with the same solvent as will be used for sample extraction. 8.4 Heating Source, capable of heating Soxhlet apparatus to achieve 10 solvent cycles per hour. Most commercially avail- able heating mantles are adequate. 8.5 Kuderna-Danish Concentrator, fitted with graduated evaporative concentrator tube. 8.5.1 Kuderna-Danish Concentrator Receiving Vessel, graduated 10-mL. A ground glass stopper is used to prevent evaporation of extracts. 8.5.2 Kuderna-Danish Evaporative Flask, 500-mL, at- tached to the concentrator tube with springs. 8.5.3 Kuderna-Danish Evaporative Flask, 40-mL, attached to the concentrator tube with springs. 8.5.4 Kuderna-Danish Snyder Column, three-ball macro. 8.5.5 Kuderna-Danish Snyder Column, two-ball micro. 8.6 Water Bath for Kuderna-Danish, heated with concentric ring cover, capable of temperature control (62°C). The bath must be used in a hood. 8.7 Chromatographic Column: borosilicate, 20-mm inside diameter, approximately 400 mm D 5369 3 NOTICE: This standard has either been superceded and replaced by a new version or discontinued. Contact ASTM International (www.astm.org) for the latest information. long, with coarse fritted plate on bottom and an appropriate solid phase. 8.8 Impermeable Sheet of PTFE-fluorocarbon-Coated Flex- ible Material, approximately 2 ft2, for sample mixing, quarter- ing, and preparation. 8.9 Stainless Steel Utensils Coated With PTFE- fluorocarbon, or other appropriate material for sample handling and mixing (that is, spatula, trowel, scoop, etc.). 8.10 Stainless Steel or Brass Sieve, 10 mesh. 9. Reagents and Materials 9.1 Purity of Reagents—Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, all reagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society where such specifications are available.9 Other grades may be used, pro- vided it is first ascertained that the reagent is of sufficiently high purity to permit its use without lessening the accuracy of the determination. 9.2 The extraction solvent of choice should be appropriate for the matrix and compounds of interest. This choice is dependent upon the chemical properties of the organic con- stituents of interest and the matrix being extracted. Literature references for solvents that have been used for Soxhlet extractions are provided in Table 1. 9.3 When specific organic compounds are to be analyzed, pesticide grade solvents (distilled in glass) are recommended. In general, the solvent blank for TSEC or for the specific compound of interest should be less than 20 % of the lowest reportable concentration required for the analysis. 9.4 Sodium Sulfate (Na2SO4), or Magnesium Sulfate (MgSO4), reagent grade, granular, anhydrous, prepared by heating at 400°C for a minimum of 4 h in a shallow tray to eliminate interfering organics. 10. Precautions 10.1 Some solvents (for example, benzene, chloroform, and carbon tetrachloride) are suspected human carcinogens and must be handled accordingly. 10.2 Explosive peroxides tend to form in ether solvents. A convenient means of testing for their presence is with E.M. Quant test paper.10 10.3 The use of fume hoods with volatile and toxic solvents is mandatory. 10.4 Flammable solvents must be kept from heat, sparks, or flames. Avoid buildup of vapors and eliminate all sources of ignition, especially nonexplosion-proof electrical apparatus and heaters. Keep containers closed. Use with adequate venti- lation. Store bulk solvents in safety cabinets. Remove only a one-day supply and keep it in a hood. 10.5 Avoid prolonged breathing of vapor or spray mist and avoid prolonged or repeated skin contact with any organic solvent. Consult Materials Safety Data Sheets for handling instructions and precautions. 10.6 Samples containing odorous, known or suspected vola- tile materials must be processed in a fume hood. 10.7 Samples known or suspected of containing toxic or hazardous materials must be handled in a fume hood. Safety information relative to the hand