改性纳米二氧化硅的制备及其对痕量钯的吸附性能研究与应用

发布时间：2018-05-30 23:08

本文选题：改性纳米二氧化硅 + 吸附性能　；参考：《湘潭大学》2015年硕士论文

【摘要】：由于纳米二氧化硅的化学活性好、表面积大、吸附容量高,在化学、力学和生物学等方面显示出很高的活性而被广泛关注,在分析检测中常被用作固相萃取剂。但是,在酸性条件下,纳米二氧化硅容易凝聚成团和失去活性。为了克服这个问题,本实验用3-氨丙基三乙氧基硅烷对纳米二氧化硅进行化学修饰,用改性后的纳米二氧化硅作为分离富集材料,以原子吸收光谱法为检测手段,对药品酒石酸唑吡坦和环境水样中的钯进行预富集与测定,由此建立了简便、高效、选择性好、灵敏度高、结果准确的检测痕量钯的新方法。本文的主要研究内容如下:1.全面综述了测定痕量金属元素的意义及方法,对常用的分离富集方法、吸附材料做了简要介绍,重点对纳米二氧化硅的特性、应用以及制备方法进行了较为详细的叙述。2.采用溶胶—凝胶法制备了纳米二氧化硅,再用3-氨丙基三乙氧基硅烷对纳米二氧化硅进行化学修饰,并运用扫描电镜,红外光谱,X-射线衍射对其修饰前后进行表征。以火焰原子吸收光谱法为检测手段,系统研究了在静态条件下改性纳米SiO2对痕量钯的吸附性能,探讨了钯在改性纳米SiO2上的最佳吸附条件和饱和吸附容量。该法应用于地质标准参考物质(批号为GBW07291)中钯的测定,实验证明此方法具有准确,灵敏,简便的特点。3.研究了改性纳米二氧化硅在动态条件下对痕量钯的吸附性能,并结合石墨炉原子吸收光谱法测定酒石酸唑吡坦中痕量钯。实验优化了具体检测条件,并对方法进行了方法学验证。该方法测定痕量钯的线性范围为0.00~400.0 ng/mL,相关系数为0.9992,方法的检出限为1.48 ng/mL,方法回收率在96.4%~101.4%之间,钯对照品溶液(100 ng/mL)的RSD为2.6%(n=7)。该方法操作简便、迅速,具有良好的精密度和准确度,可用于酒石酸唑吡坦中痕量钯的测定。4.自制PTFE微柱,将改性纳米二氧化硅作为固定相填充在其中,接入到在线流动注射的程序中,将流动注射技术与原子吸收光谱仪联用,系统研究了在线条件下改性纳米二氧化硅对痕量钯的吸附性能。方法的线性范围为5~500μg/L;相关系数为0.9987;检测限是0.248μg/L;采样体积为7.5 mL/次;测定100μg/L Pd(II)溶液RSD(n=7)为1.8%;流动注射分析的富集因子为45,采样频率(f)为12/h。该方法应用于不同环境水样中痕量钯的测定,结果满意。
[Abstract]:Because of its good chemical activity, large surface area and high adsorption capacity, nano-silica has been widely concerned because of its high activity in chemistry, mechanics and biology, and is often used as solid phase extraction agent in analysis and detection. However, under acidic conditions, nano silica is easy to agglomerate and lose activity. In order to overcome this problem, 3-aminopropyl triethoxy silane was used to chemically modify the nano-silica. The modified nano-silica was used as the separation and enrichment material, and the atomic absorption spectrometry was used as the detection method. A new method for the determination of trace palladium in zolpidem tartrate and environmental water was established. The method is simple, efficient, selective, sensitive and accurate. The main contents of this paper are as follows: 1. The significance and method of determination of trace metal elements are summarized in this paper. The common separation and enrichment methods and adsorption materials are briefly introduced. The characteristics, applications and preparation methods of nano-silica are described in detail. Nano-silica was prepared by sol-gel method and then chemically modified with 3-aminopropyl triethoxysilane. It was characterized by scanning electron microscope (SEM) and X-ray diffraction (IR). The adsorption of trace palladium (PD) by modified nano SiO2 under static condition was studied by flame atomic absorption spectrometry (FAS). The optimum adsorption conditions and saturated adsorption capacity of PD on modified nano SiO2 were discussed. The method has been applied to the determination of palladium in the geological standard reference material (batch number GBW07291). The experimental results show that the method is accurate, sensitive and simple. The adsorption properties of modified nano-silica for trace palladium under dynamic conditions were studied and the trace palladium in zolpidem tartrate was determined by graphite furnace atomic absorption spectrometry. The test conditions were optimized and the method was validated. The linear range of the method for the determination of trace palladium is 0.004 400.0 ng / mL, the correlation coefficient is 0.9992, the detection limit of the method is 1.48 ng / mL, the recovery of the method is between 96.4% and 101.4%, and the RSD of the palladium reference solution is 2.6 ng / mL. The method is simple, rapid, with good precision and accuracy, and can be used for the determination of trace palladium in zolpidem tartrate. A self-made PTFE microcolumn filled with modified nano-silica as a stationary phase was inserted into the on-line flow injection program, and the flow injection technology was combined with atomic absorption spectrometer (AAS). The adsorption of trace palladium on-line modified nano silica was studied systematically. The linear range of the method is 5 渭 g / L; the correlation coefficient is 0.9987; the detection limit is 0.248 渭 g / L; the sampling volume is 7.5 mL/; the determination of 100 渭 g / L PD II solution is 1.8%; the enrichment factor of flow injection analysis is 45, the sampling frequency is 12% h. The method has been applied to the determination of trace palladium in different environmental water samples with satisfactory results.
【学位授予单位】：湘潭大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ127.2;TB383.1

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