Selection of an efficient extraction method for the determination of polycyclic aromatic hydrocarbons in contaminated soil and sediment

Extraction with N-methyl-2-pyrrolidinone (NMP) in a microwave oven at 130°C for one hour was significantly the most efficient method for the extraction of PAHs from extraction sludge and wet harbour sediment. It was also one of the most efficient methods for extraction from air-dried industrial soil. During the first step of a two-step extraction, at least 99.8% of the PAHs were extracted with NMP. Extraction with NMP in a microwave oven was compared to extraction with acetone, methanol, ethanol, a methanol/toluene mixture, hydrolysis with KOH and tetra methyl ammonium hydroxide combined with ultrasonic treatment, rotary tumbling, Soxhlet extraction and extraction in a microwave oven. The second best method was extraction with a 4:1 (v/v) mixture of acetone and water in a microwave oven at 100°C for one hour.