【作者】 刘佳；

【导师】 常希俊；

【作者基本信息】 兰州大学 ， 分析化学， 2013， 硕士

【摘要】 当今社会环境问题、食品安全、医药安全等问题日益严峻,严重影响着人们的生活质量,如何更为有效的进行环境、食品等领域的检测与监管,已经成为每个分析化学工作者的重大责任。在这些有害物质中,金属离子的污染不容忽视,由于金属离子种类繁多、价态多样以及易于变化的特点,使得检测工作的难度大大增加。在众多检测金属离子的方法中,固相萃取(SPE)以其操作简便、选择性高以及重现性好等优势,成为进行预富集分离检测的主要方法之一。传统单一的固相吸附材料在效率、选择特异性上存在不足,经过修饰改性的材料,因其引入了O、S、N、P等元素,使得分离富集的效率大大提升,已在金属离子分离富集检测方面有了诸多令人满意的科研成果。本文通过对活性炭、硅藻土等进行修饰改性,合成新型固相萃取的吸附剂材料,并对痕量的金属离子进行分离富集的研究。1.用钙试剂(铬蓝黑R)负载改性活性炭制备出新型固相萃取吸附剂材料并将其应用于分离富集环境样品中痕量的Cr(Ⅲ)与Pb(Ⅱ)。通过静态和动态吸附试验优化各种实验条件,对最佳富集酸度、振荡时间、洗脱条件、吸附容量、方法的检出限和精密度以及实际样品的分析进行考察,得到了令人满意的结果。2.合成了糠醛修饰的硅藻土新型固相萃取吸附剂,用于富集分离环境样品中痕量Cu(Ⅱ),并通过电感耦合等离子体原子发射光谱(ICP-AES)测定。结果表明,在pH为4时吸附材料可以实现对二价铜离子的定量吸附,吸附容量为25.13mgg-1,检出限为0.19ng mL-1,富集因子为150。3.将多壁碳纳米管用铜试剂(BZO)负载改性后用于分析检测液体样品中痕量的Cr(Ⅲ)、Cu(Ⅱ)、Fe(Ⅲ)和Pb(Ⅱ)离子。实验结果表明,该方法对Cr(Ⅲ), Cu(Ⅱ)、Fe(Ⅲ)和Pb(Ⅱ)离子的检出限分别为0.65、0.77、0.40以及0.45ng mL-1,相对标准偏差小于3.5%(n=8),得到了满意的分析结果。更多还原

【Abstract】 In today’s society, environmental issues, food and drugs safety have become a serious problem, which affected the quality of people’s life badly and how to detect and supervise the environment and food have become a major responsibility of each analytical chemistry workers. In those harmful substances, metal ions pollution can’t be ignored because metal ions possess many species, valence states and are easy to change, which increased the difficulty of the detection work. Solid phase extraction (SPE) has become the major method to the separation and preconcentration of metal ions because of its advantage of simple operation, high selectivity and good reproducibility detection of metal ions among so many other methords. The traditional solid phase adsorption materials is present problems in efficiency and the choice of specific, but the modified materials which introduced O, S, N, P and other elements, enhanced the efficiency of separation and preconcentration greatly and with satisfactory achievements in scientific research on metal ions. This paper shows that modified activated carbon or diatomite so as to form novel solid-phase extraction materials and do some research on trace metal ions’separation and preconcentration.1Calcium reagent (Eriochrome Blue Black R) loaded and modified activated carbon to produce a new SPE sorbent material and apply to the separation and enrichment of trace Cr(Ⅲ) and Pb (Ⅱ) in environmental samples.Through static and dynamic adsorption experiments to examine the optimization of experimental conditions of the optimum preconcentration acidity, oscillation time, adsorption capacity, elution conditions, the detection limit and precision as well as the analysis of real samples and the satisfactory result was obtained.2The synthesis of a new type of solid phase extraction adsorbent by using furfural modified diatomite, which was used to measure trace Cu (Ⅱ) in environmental samples and was detected by inductively coupled plasma atomic emission spectrometry (ICP-AES). The results show that, at pH4, this adsorption material can achieve quantitative adsorption of Cu (Ⅱ) and its adsorption capacity is25.13mg g"1, the detection limit is0.19ng mL-1, enrichment factor is150.3Multi-walled carbon nanotubes were loaded by copper reagent (BZO) to adsorb and analysis trace Cr (Ⅲ), Cu (Ⅱ), Fe (Ⅲ) and Pb (Ⅱ) in liquid samples. The experimental results show that this method can analysis trace Cr (Ⅲ), Cu (Ⅱ), Fe (Ⅲ) and Pb (Ⅱ) and the detection limit was0.65,0.77,0.40and0.45ng mL-1, respectively, the relative standard deviation is less than3.5%(n=8), the results were satisfactively.更多还原