Preparation And Application Of Novel Solid-phase Extraction Material For The Analysis Of Polycyclic Aromatic Hydrocarbon

Solid phase extraction(SPE) is currently the most commonly method of sample preparation. SPE has many merits such as high enrichment factor, rapid extraction procedure, convenient operation, low solvent consumption, and suitable for analysis of trace organic compounds from a variety of medium such as air, water and biological sample. In this paper, several solid phase extraction sorbents were developed and applied to the analysis of polycyclic aromatic hydrocarbons(PAHs) in water samples. Firstly, in the aspect of magnetic solid phase extraction(MSPE), fluorenyl and cholesterol functionalized magnetic nanoparticles(MNPs) were prepared. MNPs were coated with 3-aminopropyltriethoxysilane based on Fe3O4 and further modified. Hydrophobic effect and π-π interaction were contributed to selectively enrichment of PAHs. Otherwise, a new material which named foam metal was introduced to SPE sorbent. In this respect, dopamine and C18 coated nickel foam was prepared respectively, and this is the first time that nickel foam used as SPE sorbent.The contents of this thesis were summarized as follows:1. Fluorenyl functionalized superparamagnetic core/shell MNPs(Fe3O4@Si O2@Flu) were prepared and characterized by transmission electron microscope, X-ray diffraction and infrared spectroscopy. The MNPs having an average diameter of 200 nm were then used as solid-phase extraction sorbent for the determination of 16 priority pollutants PAHs in water samples designated by United States Environmental Protection Agency(U.S. EPA). The main influencing parameters, including sorbent amount, desorption solvent, sample volume and extraction time were optimized. Analyses were performed on gas chromatography-mass spectrometry(GC-MS) using selected ion monitoring(SIM) mode. Method validation proved the feasibility of the developed sorbents for the quantitation of the investigated analytes at trace levels. Limit of detection ranging from 0.5 to 4.0 ng/L were obtained. The repeatability was investigated by evaluating the intra- and inter-day precisions with relative standard deviations(RSDs) lower than 13.1%. Finally, the proposed method was successfully applied for the determination of PAHs in water samples with the recoveries in the range of 96.0-106.7%.2. A MSPE protocol combining a static headspace gas chromatography coupled to mass spectrometry(HS-GC-MS) method has been developed for extraction, and determination of 16 PAHs in drinking water samples. Magnetic nanoparticles were coated with 3-aminopropyltriethoxysilane and modified by cholesterol chloroformate. Transmission electron microscope, vibrating sample magnetometer, Fourier transform infrared spectrometry and X-ray photoelectron spectroscopy were used to characterize the cholesterol-functionalized sorbents, and the main parameters affecting the extraction as well as HS sampling, such as sorbent amount, extraction time, oven temperature and equilibration time have been investigated and established. Combination with HS sampling, the MSPE procedure was simple, fast and environmentally friendly, without need of any organic solvent. Method validation proved the feasibility of the developed sorbents for the quantitation of the investigated analytes at trace levels obtaining the limit of detection(S/N = 3) ranging from 0.20 to 7.8 ng/L. Good values for intra and inter-day precision were obtained(RSDs≤9.9%). The proposed method was successfully applied to drinking water samples.3. polydopamine coated 3D nickel foam(NF-PDA) were prepared and characterized,and applied as sorbent for the extraction of 16 PAHs from water samples. NF-PDA were synthesized by situ oxidative self-polymerization procedure and characterized by using the techniques of scanning electron microscopy, energy dispersive spectrum analysis(EDS) and XPS. Its performance was evaluated by the SPE of 16 PAHs from water samples, followed by GC-MS analysis. The effects of the main experimental parameters(i.e. sorbent amount, desorption solvent, sample volume and extraction time) that could affect the extraction efficiencies were investigated. The results demonstrated that the NF-PDA had an excellent adsorption capability for the compounds. The methodology was validated for river water and wastewater, obtaining recoveries ranging from 89.6 to 97.5% with relative standard deviation values lower than 7.3% and limits of detection in the range 2.3-16.5 ng/L.4. A novel approach based on octadecyl functionalized 3D nickel foam(NF-C18) coupled with SPE and GC-MS was developed for the rapid enrichment and determination of 16 PAHs from water samples. NF-C18 was synthesized by the two-step reactions of in situ silanization and alkylationsitu, and characterized by using the techniques of scanning electron microscopy, FTIR and XPS. The effects of the main experimental parameters(i.e. sorbent amount, desorption solvent, sample volume and extraction time) that could affect the extraction efficiencies were investigated. The results demonstrated that the NF-C18 had an excellent adsorption capability for the compounds. The methodology was validated for river water and wastewater.