title: Study of factors affecting on the extraction efficiency of polycyclic aromatic hydrocarbons from soils using open-vessel focused microwave-assisted extraction.
abstract: As part of an evaluation of focused microwave-assisted extraction (FMAE) using an open-vessel system, the effects of matrix, moisture content, ageing, and solvent have been studied on the extraction efficiency of polycyclic aromatic hydrocarbons (PAHs) from spiked soils. PAHs were spiked onto three different uncontaminated air dried and originally wet soil matrices with 1- and 20-day ageing periods. Solvents used were hexane-acetone (1:1), cyclohexane-acetone (1:1) and dichloromethane. FMAE only required a small amount of solvent (20 ml) and short extraction time (10 min) in the open cell under 90 W of microwave power. The results revealed that the extraction efficiency strongly depends on the nature of soil matrix; moisture content may enhance the recoveries of PAHs for many cases; and, the influence of the type of solvent is not significant. A comparison between microwave extraction and 16-h Soxhlet extraction has been made on spiked soils. It evidenced that the microwave method under ambient pressure is a suitable alternative to Soxhlet method for the analysis of PAHs in soils. For the evaluation of the developed FMAE method, three reference materials were used. The PAHs recovered from three reference materials were in a good agreement with reference values.
authors.affiliation: Environmental Analysis Laboratory, Department of Chemistry, National Kaohsiung Normal University, 802 Kaohsiung, Taiwan, ROC. shuyy@nknucc.nknu.edu.tw
authors.forename: Youn Yuen
authors.initials: YY
authors.lastname: Shu
authors.forename: Teh Long
authors.initials: TL
authors.lastname: Lai
authors.forename: Huann-shyang
authors.initials: HS
authors.lastname: Lin
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Yang
authors.forename: Chi-Peng
authors.initials: CP
authors.lastname: Chang
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000295:instrumentation / Q000379:methods*; D008872:Microwaves; D011084:Polycyclic Aromatic Hydrocarbons / Q000302:isolation & purification*; D012015:Reference Standards; D015203:Reproducibility of Results; D012987:Soil / Q000032:analysis; D012989:Soil Pollutants / Q000302:isolation & purification; D012997:Solvents / Q000737:chemistry; D013997:Time Factors
chemical_list: D011084:Polycyclic Aromatic Hydrocarbons; D012987:Soil; D012989:Soil Pollutants; D012997:Solvents