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.

Determination of 16 polycyclic aromatic hydrocarbons in seawater using molecularly imprinted solid-phase extraction coupled with gas chromatography-mass spectrometry

“…Sixteen standard PAHs, i.e., naphthalene (Nap), acenaphthylene (Acy), acenaphthene (Ace), fluorene ( The related information such as structures and physicochemical properties of the 16 PAHs can be found in our previous work [9]. Stock solutions at the concentration of 10 mg L À 1 were prepared in acetonitrile, and working solutions were prepared daily by appropriate dilution of the stock solutions with seawater before use.…”

“…By monitoring the temporal amount of PAHs in the solutions, the procedures of the dynamic adsorption test were performed as follows: 50 mg of MIPs were dissolved in 10 mL of seawater spiked with 2 mg L À 1 individual PAH standards, and then the mixture was continuously oscillated in a thermostatically controlled water bath at room temperature for 1-24 h; the polymers were removed centrifugally, and then the 5 mL of supernatant was extracted by using dispersive liquid-liquid microextraction (DLLME) procedure [9,33,34] into a 10 mL glass-centrifuge tube; and then the analytes were located in the bottom of the tube, 1 mL of which was sampled for GC-MS analysis. For each adsorbent, these experiments were repeated at least triplicates.…”

“…However, because of the complexity of matrix and low content of PAHs, high efficiency clean-up and enrichment procedures are required prior to analysis [6][7][8]. Various pretreatment processes for the extraction and concentration of PAHs from water samples have been increasingly developed, such as liquid-phase microextraction (LPME) [9], solid-phase extraction (SPE) [10,11], stirring bar sorptive extraction (SBSE) [12], and solid-phase microextraction (SPME) [13]. SPE, due to its advantages [10,14], has been widely employed for concentration of PAHs in water samples [10,11,15,16].…”

Recent Advances in Dispersive Liquid - Liquid Microextraction for Organic Compounds Analysis in Environmental Water: A Review

“…A simple and rapid ultrasound-assisted DLLME (UA-DLLME) technique has been developed for diverse organic pollutants [96][97][98][99]. Compared to the conventional DLLME, an ultrasound-assisted process was applied to accelerate the formation of the fine cloudy solution.…”

“…The linear ranges obtained for all analytes were 0.01-2.0 μg mL -1 with LODs ranged from 0.14 to 0.81 μg L -1 . Lately, the UA-DLLME was also further developed by Chen and co-workers [99,100]. Sixteen PAHs in seawater samples were excellently separated and determined by UA-DLLME combined with little solvent consumption by GC-MS [99], and five sulfonamides were successfully detected in several environmental water samples by UA-DLLME coupled with capillary electrophoresis (CE) with the aid of experimental design [100].…”