Abstract
This study investigated how two factors, extraction solvent and time, affected extraction efficiencies of ultrasonic extraction (UE) for polycyclic aromatic hydrocarbons (PAHs). The initial extraction has great impact on the final extraction efficiencies of PAHs, and further affects the quantitative analysis of PAHs. In this study, the former factor inspected parameters of type of extraction solvent, composition of solvent, and solvent dosage, while the latter concerned UE duration per cycle and number of UE cycles. Results showed that single solvents, n-hexane, dichloromethane (DCM), and acetone, provided average recovery rates of 53.76%+/- 63.21% (average value +/- standard deviation), 37.81%+/- 19.48%, and 67.66%+/- 60.76%, respectively, for the total PAHs targeted. However, binary solvents, n-hexane/DCM (1: 1), DCM/acetone (1: 1), and acetone/n-hexane (1: 5), yielded average recovery rates of 112.08%+/- 39.23%, 82.56%+/- 48.78%, and 52.77%+/- 30.45%, respectively, for the total target PAHs. The three single solvents yielded average recovery rates of 0-22.32% for 3-ring PAHs, 6.01-41.76% for 4-ring PAHs, and 46.53-85.71% for 5- and 6-ring PAHs, while the three binary solvents provided 29.64-31.00%, 19.65-40.62%, and 28.38-49.78% for the three types of PAHs, respectively. The other three parameters supplied with similar recovery rates for these types of PAHs. When applying n-hexane/DCM(1: 1) as PAH extraction from real airborne particulate matter, the three types of PAHs occupied 9.31%, 21.40%, and 69.29% over total PAHs, respectively.