Cooling assisted headspace microextraction by packed sorbent coupled to HPLC for the determination of volatile polycyclic aromatic hydrocarbons in soil.

A headspace microextraction by packed sorbent technique (HS-MEPS) was developed that is assisted by cooling the extraction phase and, in the same time, heating the sample matrix. The innovated cooling assisted HS-MEPS system was optimized for the extraction and HPLC determination of volatile polycyclic aromatic hydrocarbons (PAHs) in solid samples. Amino ethyl-functionalized SBA-15 was used as a nanoporous sorbent for packing the conical hub of the MEPS syringe. For efficient extraction of PAHs, several parameters such as the nature and mass of sorbent, eluent type, elution volume, extraction temperature and number of draw-eject cycles of the syringe were studied and optimized. Under the optimal experimental conditions, only 2 mg of the sorbent was sufficient by applying a temperature of 0 °C to the sorbent while the sample was heated up to 150 °C. Linear calibration curves (R > 0.95) were obtained for all the studied PAHs and their quantitation limits were in the range of 0.042-0.25 ng g. The method was successfully applied to the extraction and HPLC analysis of PAHs in some polluted soil samples.