Alkaline extraction in combination with microwave-assisted extraction followed by solid-phase extraction treatment for polycyclic aromatic hydrocarbons in a sediment sample.

Microwave-assisted extraction using 1M KOH/methanol (alkaline-MAE) in combination with solid-phase extraction treatment was developed and applied to polycyclic aromatic hydrocarbons (PAHs) in a sediment sample. Although various conditions were examined (100 or 150 degrees C for 10 or 30 min), comparable concentrations of PAHs to those obtained by conventional extraction with 1M KOH/methanol at 70 degrees C for 4h were obtained, even at 100 degrees C for 10 min. The concentrations obtained by using MeOH at 150 degrees C for 30 min without KOH were lower (by 1.3-37%) than those obtained by alkaline-MAE at 150 degrees C for 30 min. Since the developed technique can introduce higher concentration of benzo[ghi]perylene relative to those using pressurized liquid extraction (toluene, 150 degrees C, 15 MPa, 10 min, two cycles), the developed alkaline-MAE is a effective technique.