Extraction of Priority Pollutants from Solids

Tests have been conducted to determine the efficiency of and factors affecting extraction of semivolatile organic priority pollutants from solid samples using modified Soxhlet procedures. Test variables included time of solvent contact, particle size of solid matrix, and type of solvent. The results indicated that extraction efficiences varied substantially for different priority pollutants. The most important factor in obtaining maximum recovery seemed to be the contact time during extraction. Particle size had a minor bearing on extraction efficiency. Solvent losses contributed significant errors when using extraction times longer than 24 hours. When proper consideration is given to the extraction efficiencies and to other sources of error, the Soxhlet procedure is useful for providing estimates of the quantities of semivolatile priority pollutants in solids.