Optimization of two different dispersive liquid-liquid microextraction methods followed by gas chromatography-mass spectrometry determination for polycyclic aromatic hydrocarbons (PAHs) analysis in water.
Novel sample preparation methods termed "up-and-down shaker-assisted dispersive liquid-liquid microextraction (UDSA-DLLME)" and "water with low concentration of surfactant in dispersed solvent-assisted emulsion dispersive liquid-liquid microextraction (WLSEME)" coupled with gas chromatography-mass spectrometry (GC-MS) have been developed for the analysis of 11 polycyclic aromatic hydrocarbons (PAHs) in aqueous samples. For UDSA-DLLME, an up-and-down shaker-assisted emulsification was employed. Extraction was complete in 3min. Only 14 μL of 1-heptanol was required, without a dispersive solvent. Under the optimum conditions, the linear range was 0.08-100 µg L(-1), and the LODs were in the range 0.022-0.060 µg L(-1). The enrichment factors (EFs) ranged from 392 to 766. Relative recoveries were between 84% and 113% for river, lake, and field water. In WLSEME, 9 μL of 1-nonanol as extraction solvent and 240 μL of 1 mg L(-1) Triton X-100 as surfactant were mixed in a microsyringe to form a cloudy emulsified solution, which was then injected into the samples. Compared with other surfactant-assisted emulsion methods, WLSEME uses much less surfactant. The linear range was 0.08-100 µg L(-1), and the LODs were 0.022-0.13 µg L(-1). The EFs ranged from 388 to 649. The relative recoveries were 86-114% for all three water specimens.
Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan.
Wan-Chi
WC
Tseng
Department and Graduate Institute of Forensic Medicine, National Taiwan University, Taipei 10002, Taiwan. Electronic address: paishanchen@ntu.edu.tw.
Pai-Shan
PS
Chen
Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan. Electronic address: sdhuang@mx.nthu.edu.tw.
Shang-Da
SD
Huang
D004655:Emulsions / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D057230:Limit of Detection; D059627:Liquid Phase Microextraction / Q000379:methods*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis*; D012997:Solvents; D013501:Surface-Active Agents / Q000737:chemistry; D014867:Water / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis*
D004655:Emulsions; D011084:Polycyclic Aromatic Hydrocarbons; D012997:Solvents; D013501:Surface-Active Agents; D014874:Water Pollutants, Chemical; D014867:Water
Gas chromatography−mass spectrometry (GC−MS); Polycyclic aromatic hydrocarbons (PAHs); Up-and-down shaker-assisted dispersive liquid–liquid microextraction (UDSA−DLLME); Water with low concentration of surfactant dispersive liquid–liquid microextraction (WLSEME)