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 extraction of nonvolatile or semivolatile organic compounds from the above solid waste should use solvents listed in Table 1 or SW846 Method 3540.
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.
The method detection limit can be adjusted by varying the volume of extract used and by additional sample clean-up prior to analysis.
Soxhlet extraction has an advantage when analyzing solid waste and soil/waste mixtures which form emulsions with more rigorous solvent mixing extraction techniques.
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) |