Study On The Analytical Methethods Of Cu(Ⅱ), Cd(Ⅱ) In Water And Sudan Ⅱ In Chili Powder By Solid Phase Extraction With Nanofiber

The diameter of Electrospinning nanofibers is between10-900nm, with a great specific surface area, high porosity, strong adsorption, strong ability to penetrate and so on. In view of its special physical, chemical, and electrical and other characteristics, it has become a hot research field of the current science and technology. It is widely used in cosmetics, filtration and protective materials, composites, nano-electronics, nano-chemistry, sensors, environmental testing, the pharmaceutical, biotechnology and other fields. At present, the using of electrospinning nanofibers as chemical analysis of enriched material is a new development direction. This paper reported to use polystyrene electrospinning nanofibers nano-scale, weak polar and fiber network criss-crossing, to solid-phase extraction for concentrating low-enriched polar substances. Compared with other traditional extraction methods, the use of material consumption, organic solvents and the pollution to environment characteristics is low. The thesis includes two parts: In chapter I:Application research of solid phase extraction with nanofiber on determination Cu2+、Cd2+in waterElectrospinning polystyrene nanofiber is used as solid phase micro-extraction material. Using1-(2-Pyridylazo)-2-naphthol as chelating agent and the methanol as eluent, trace Cu2+、Cd2+in water is concentrated with the fiber and analysed by graphite furnace atomic absorption. At pH7.5, the adsorption capacities of the fiber for Cu2+and Cd2+are2.5μg/mg,1.7μg/mg, respectively. The linear ranges of Cu2+and Cd2+are2.0-50μg/L and0.2-6μg/L with the correlation coefficient of0.9993and0.9995, respectively. The limits of detection (LODs) are0.5and0.02μg/L, respectively. The analysis methods of Cu2+and Cd2+can be applied to the huaihe river water, the mineral water and the tap water. With this method, the range contents of Cu+and Cd2+in the three water samples are2.25-3.83μg/L and0.10-0.16μg/L. The methods are suitable for the requirement of determination water. Under optimum conditions,4μg/L、16μg/L Cu2+and0.2μg/L、4μg/L Cd2+are added to the huai river water, mineral water and tap water. The recoveries of spiked samples are83.0%-88.8%,80.0%-90.0%with the RSDs of0.57%-4.56%,0.81%-5.79%. In chapter II:Application research of nanofiber for determination of Sudan Ⅱ in chili powder with linear scan polarographyAn electrospinning polystyrene nanofiber is used for materials of solid phase extraction (SPE). By using10%acetone aqueous solution as carrier liquid and acetone as eluent, trace Sudan Ⅱ in chili powder are enriched. Sudan Ⅱ shows a sensitive reduction peak at-0.93V on its linear scan polarogram in a buffer solution of borax-NaOH buffer solution (pH11.5) with acetone selected as a co-solvent to dissolve it. The peak current is linearly proportional to the concentration of sudanⅡ in the range of2×10-2to2×10-1mg/L with coefficient of0.9947. The detection limit is3×10-3mg/L. This method is applied to the determination of sudan Ⅱ in chili powder with the spiked recoveries are78.0%-85.7%.