| A subject of great interest in environmental science is the determination of toxic and harmful substance in environment matrix including atmosphere, water and soil. Until now, many analytical methods, such as high-performance liquid chromatography, gas chromatography, capillary electrophoresis, atomic absorption spectrometry and atomic emission spectrometry, were employed in the detection of both inorganic and organic pollutants. Due to the low concentrations of pollutants residued in environmental samples and higher matrix interferences of some complex sample, sample pretreatment processes have to be employed to for the separation, enrichment and purification. Traditional sample pretreatment technologies, such as liquid-liquid extraction and Soxhlet extraction, can't reach the requirement of environmental analysis on account of the complex operations, insufficient accuracy and precision, high dosage of organic solvent, which are easy to cause secondary pollution to environment. Therefore, development of simple, rapid and efficient sample pretreatment technology becomes one of hot topics of environmental science. So far many new sample pretreatment technologies have been developed, such as cloud point extraction, solid phase extraction (SPE), solid phase microextraction (SPME), spercritical fluid extraction (SFE) and so on. Among them, SPE are widely used in pretreatment of environmental and biological sample owing to the high enrichment efficiency, low dosage of organic solvent and easy automation. The choice of adsorbent is one the most important influence factors. Commercial adsorbents including C8, C18, Oasis HLB and graphitized carbon black, etc have shortcomings in adsorptive selection and reusability, which led to the demand of exploring new adsorptive materials. In past years, nanomaterials and biomaterials achieve much attention because of their unique structure and property. For example, some research results have shown that carbon nanotubes and eggshell membrane have a good adsorption for a variety of heavy metal ions and organic contaminants. Hence the thesis focused on the application potential of carbon nanotubes and eggshell membrane selected as the research object. This thesis is mainly composed of six chapters:The first chapter: The development of new adsorptive materials is the studying emphasis of the sample pretreatment technologies. The application of several new SPE adsorbents, such as carbon nanotubes, molecular imprinted polymers, nanoparticles, biosorbent, etc was reviewed in this chapter. The perspeciive and future trends in the use of these materials were also simply demonstrated.The second chapter: Multiwalled carbon nanotubes (MWCNTs) were used as a novel kind of solid-phase extraction adsorbents in this work as well as an analytical method based on MWCNTs SPE combined with high-performance liquid chromatography (HPLC) was established for the determination of polycyclic aromatic hydrocarbons (PAHs), some of which belong to typical persistent organic pollutants (POPs). Several conditions that probably affected the extraction efficiency including the eluent volume, sample flow rate, sample pH and the sample volume were optimized in detail. It indicated that the highest enrichment efficiency was obtained for ten PAHs when 5 mL acetonitrile was selected as eluent, and the optimal flow rate, pH, and volume of water sample were 4 mL min-1, pH3-10, 500 mL respectively. Subsequently, the correlation parameters of this method were determined at the optimal conditions. Experimental results showed that the linear ranges were 0.04-100μg L-1, relative standard deviations (RSD) were 1.7-4.8% and the detection limits (LOD) were 0.005-0.058μg L-1, Finally, the established method was applied in the determination of real environmental water samples such as tap water, river water and domestic wastewater. The recoveries of PAHs spiked in environmental water samples ranged from 78.7 to 118.1%. It was concluded that MWCNTs packed cartridge coupled with HPLC was an excellent alternative for the routine analysis of PAHs at trace level.The third chapter: The potential of eggshell membrane (ESM) as a novel SPE bio-adsorbent was investigated in the present chapter. The ESM with a unique structure of intricate lattice network composed of protein fibers showed a predominant ability to capture linear alkylbenzene sulfonates (LAS) as a model of organic micro pollutants by the electrostatic interactions between positively charged ESM surfaces derived from the protonation of amines and amides functional groups in its structure under acidic media and negatively charged LAS. A new method based on the combination of ESM-SPE system and HPLC was established for detecting LAS in environmental water samples. The optimal SPE conditions were obtained through investigating in detail. As the results of experiment, the sample flow rate was 2 mL min-1, the pH of sample solution was6, the content of NaCl was 1% (w/v), the eluent was 5 mL methol, the sonication time was 2min and sample volume was 500 mL. Under the optimal conditions, the linear range, RSD and LOD of the proposed method were 0.2-100μg L-1, 1.0-8.2% and 0.010-0.027μg L-1, respectively. Then the method was adapted for determining the real water sample including tap water and river water. A comparison study with ESM, C8 and C18 as adsorbents for LAS demonstrated that the recoveries of ESM-based bioadsorbent (94.2-116.0%) were advantageous over C8 (38.0-110.4%) and C18 (29.7-82.7). This work provides a natural biomaterial-based SPE format for monitoring organic analytes in real environmental samples. This research enlarges the application area of ESM by pioneering a new aspect as SPE adsorbent with important theoretical significance and wide application prospects, which provides an effective method for extracting and detecting means. Besides, the satisfactory results showing a good removal efficiency of LAS in water matrix.The fourth chapter: Sudan dyes including Sudan I, Sudan II, Sudan III and Sudan IV were chosen as target compounds in order to discuss the applied potential of ESM as adsorbent in static SPE method. The experimental conditions such as eluent, the flow rate, pH and volume of water sample were optimized at first and the results indicated that the optimal conditions were 40 min, 100 r min-1, 1 mL ethanol, pH7, and 250mL, respectively. It was shown that the linear ranges were 0.02-160μg L-1, RSDs were 1.5-3.4%, LODs were 0.34-0.305μg L-1 under the optimal SPE conditions. Good results with spiked recoveries in the range of 89.7-115.5% were achieved from the determination of environmental water samples and food samples. The conclusion of this chapter expands the application domains of ESM as SPE adsorbents, and gives a new direction for other sample pretreatments.The fifth chapter: A solid phase extraction (SPE) format with eggshell membrane (ESM) as a functionalized bio-platform for hemimicelle/admicelle as adsorbent for enriching polycyclic aromatic hydrocarbons (PAHs) was firstly investigated. It was demonstrated that ESM templating of the mixed hemimicelle/admicelle of linear alkylbenzene sulfonates (LAS) can be used as SPE adsorbent for enriching PAHs as a model of organic pollutants in environmental aqueous samples. In the batch experiment, adsorption kinetics related to the four homologues of LAS under acidic condition showed that the time needed to attain equilibrium was independent of the length of the hydrophobic chain at low concentration levels. The adsorption isotherms of anionic surfactant LAS on ESM demonstrated a typical three-region model, suggesting the surfactants self-assembly behavior was similar to that of surfactant on inorganic oxides. This proved the formation of hemimicelle, hemimicelle and admimicelle mixture as well as admimicelle. It was revealed through further investigation that the best enrichment efficiencies of PAHs were obtained at a certain LAS concentration (0.5 mmol L-1. Subsequently, several influencing factors including sample pH, flow rate, volume and the kind and volume of eluent were studied and optimized. On the basis of optimal determining conditions of the target PAHs, the linear ranges were0.02-6μg L-1, RSDs were 0.6-3.8%, and the LODs were 0.1-8.6 ng L-1 respectively. The system showed a good PAHs enrichment ability of ESM biomaterial templating of hemimicelle/admicelle with high sensitivity, and could be successfully used for the detection of PAHs in environmental water samples. A comparison study with hemimicelle/admicelle and C18 as adsorbents for PAHs demonstrated that ESM-based hemimicelle/admicelle adsorbent was advantageous over C18 for tap and river water samples. The research developed a new fabrication for the hemimicelle/admicelle adsorbent, and will plays an important role in research of environmental behavior and separation/enrichment of non-polar organic pollutants.The sixth chapter: This chapter initially discussed the adsorption mechanism of aromatic compounds onto the ESM in aqueous solution, focusing on the formation of anionic surfactant hemimicelle/admicelle on the surface of ESM and its effect on the adsorption behavior of aromatic compounds. As well, three candidates of PAH compounds, naphthalene, phenanthrene and pyrene, were chosen as model compounds for the research of competitive adsorption. Experimental results showed that self-assembly behavior of surfactant have the following influences on the adsorption of aromatic compounds: 1, the highest adsorption capacity of ESM was obtained when the LAS formed the saturated monolayer of mix micelles, while the adsorption amount of phenol and naphthalene showed a current with the declining current with the increase of LAS concentration. The possible reason maybe was due to the easy ionization of phenolic compounds, which introduced negative charge on the surface of ESM. The phenomenon could lead to the competitive adsorption between anionic surfactant LAS and phenolic compounds. 2, the hemimicelle/admicelle had higher adsorption amounts of naphthyl compounds than the phenyl compounds. The results of competitive adsorption between naphthalene, phenanthrene and pyrene also indicated that the adsorption amount decreased in the order of pyrene> phenanthrene > naphthalene. Besides, the adsorption amount declined significantly when phenanthrene and pyrene co-existed. Based on the results, it was concluded that hydrophobic interaction between aromatic compounds and hemimicelle/admicelle on the ESM template was the primary adsorption mechanism.
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