Ultrasound-Assisted Dispersive Liquid–Liquid Microextraction Combined with Low Solvent Consumption for Determination of Polycyclic Aromatic Hydrocarbons in Seawater by GC–MS

Abstract

Ultrasound-assisted dispersive liquid–liquid microextraction (USA-DLLME) with low solvent consumption was demonstrated for gas chromatography-mass spectrometry (GC–MS) determination of 16 typical polycyclic aromatic hydrocarbons (PAHs) in seawater samples. Factors affecting the extraction process, such as extraction and dispersive solvent, phase ratio, temperature, extraction and centrifugation time, were investigated thoroughly and optimized. The linear range was 20–2,000 ng L−1 except for acenaphthylene (Acy) at 10–2,000 ng L−1 and phenanthrene (Phe), fluoranthene (Flu) and pyrene (Py) all at 5–2,000 ng L−1. Enrichment factors (EFs) ranging from 722 to 8,133 were obtained, achieving limits of detection at 1.0–10.0 ng L−1. The method attained good precision (relative standard deviation, RSD) from 3.4 to 14.2% for spiked 50 ng L−1 individual PAHs standards. Method recoveries were in the range 87–124% and 70–127% for spiked samples from simulated seawater and beach seawater, respectively. The proposed USA-DLLME helped to obtain about 1.1–10 times higher EFs in a minimum amount of solvent and in less time than traditional DLLME.