【作者】 崔月梅；

【导师】 常希俊；

【作者基本信息】 兰州大学 ， 分析化学， 2008， 博士

【摘要】 随着科学技术和工业生产的快速发展,来自生产过程中的重金属元素的消耗和排放与日俱增,造成日趋严重的环境污染,成为影响人民健康水平和社会经济发展的一个主要因素。准确测定地质、生物和环境样品中的痕量元素是分析化学中一项十分重要并具有挑战性的工作;尤其是环境水样中重金属离子的含量需做常规的监测。利用现代原子光谱技术直接测定低浓度的痕量元素一般很困难,原因不仅是方法的灵敏度不够,而且还有来自基体效应的影响。因此,从基体中分离和预富集痕量元素显得十分必要。毫无疑问,固相萃取（SPE）是当今最流行的样品预处理方法,是分离科学中最具活力的分支,广泛应用于环境、药物、临床、食品和化工等领域。在痕量元素的预富集和分离中固相萃取有以下几个主要优点（1）操作简便;（2）高的富集因子:（3）快速相分离;（4）易与不同的检测技术相结合。固相萃取作为一种新型的样品预处理技术,目前在简化样品的处理过程和提高方法的自动化方面,不断地得到深化和发展,并期望通过新的化学吸附剂、尤其是具有特殊性能的吸附剂的发现和使用,实现从复杂基体中预富集和分离被分析物的目的。过去发展了各种各样的吸附剂和样品处理方法,极大地方便了各种样品的预处理过程,扩大了方法的应用范围。当前发展选择性更好的吸附剂和萃取程序仍然是固相萃取研究的活跃领域。因此,本论文重点是以建立重金属的预富集分离与选择性富集及分析为目的,合成了几种新型的吸附材料,并对合成条件以及材料的选择吸附性能开展了系统研究,主要进行了以下几方面的创新性研究工作。1.以APS与CPS为硅烷偶联剂,用对二甲氨基苯甲醛、磺基水杨酸、桑色素、磺胺和氧氟沙星成功修饰了纳米SiO₂和硅胶,将合成的新型固相萃取吸附剂用来富集分离溶液中痕量Cr（Ⅲ）,Cu（Ⅱ）,Fe（Ⅲ）,Pb（Ⅱ）,Ni（Ⅱ）,Cd（Ⅱ）和Zn（Ⅱ）离子,用电感耦合等离子体原子发射光谱进行测定。详细研究了富集分离的条件和性能（富集酸度、洗脱酸度和体积、流速、抗干扰能力、精密度和准确度等）并建立了相应的分析方法,应用于生物样品和水样中痕量金属离子的测定,分析结果满意。与未经处理的纳米SiO₂和硅胶相比,修饰的纳米SiO₂和硅胶在预富集和分离痕量的重金属离子时具有较高的选择性和吸附容量。2.用铜试剂负载活性炭,合成了新型固相萃取吸附剂,用来富集分离溶液中痕量Pb（Ⅱ）和Cr（Ⅲ）离子,用电感耦合等离子体原子发射光谱进行测定。详细研究了富集分离的条件和性能（富集酸度、洗脱酸度和体积、流速、抗干扰能力、精密度和准确度等）并建立了相应的分析方法,应用于生物样品和水样中痕量金属离子的测定,分析结果满意。与未经处理的活性炭相比,修饰的活性炭在预富集和分离痕量的金属离子时具有较高的吸附活性和选择性。3.应用硅胶表面修饰技术,首次将Pb（Ⅱ）作为印迹离子合成了Pb（Ⅱ）印迹聚合物,研究了印迹离子聚合物和非印迹聚合物对Pb（Ⅱ）的分离富集特性,建立了分离富集测定Pb（Ⅱ）的新方法。对照了印迹聚合物和非印迹聚合物对模板离子的吸附选择性,结果表明印迹聚合物对模板离子具有较高的亲和性和选择吸附性能。更多还原

【Abstract】 With the rapid development in science and technology and proceeding industrialization,the consumption and draining of heavy metals and organic substance are increasing daily.The pollution caused by heavy metals and poisonous organic substance become more severe,which is also a dominant factor for jeopardizing the public health and preventing social economical development of our country.The accurate determination of trace element in geological,biological and environmental samples is an important and challenging task in analytical chemistry;especially heavy metals are often routinely monitored in environmental water.Direct determination of trace elements at low concentrations by modern atomic spectrometric techniques is often difficult,not only because of the insufficient sensitivity of the methods,but because of matrix effects.For this reason,the preliminary separation and preconcentration of trace elements from matrix is often required.There can be no doubt that solid-phase extraction（SPE）is today the most popular sample preparation method.It is a very active area in the field of separation science （such as environmental,pharmaceutical,clinical,food and industrial chemistry,etc.）. SPE has several major advantages in separation and preconcentration of trace elements,including（i）simple to operate;（ii）high preconcentration factor;（iii）rapid phase separation;（ⅳ）and the ability to combine with different detection techniques. The methodology continues to evolve,through changes in format more than principle, in response to the desire to simplify the sampling process or facilitate automation. Advances are expected in sorbent chemistry,particularly class-specific sorbents for the isolation and clean-up of target analytes in complex matrices.Over time,various sampling formats and sorbents have been developed to facilitate the convenient processing of different sample types and to extend the scope of the method.At present, SPE is still an active area of research to develop new and more selective sorbents or procedures.The synthesis of new adsorption materials and their adsorption selectivity characteristics for trace heavy metals have been investigated systematically.The more detailed novelty of this research can be categorized as following:（1）Nanometer SiO₂ and silica gel was modified with p-dimethylaminobenzaldehyde（p-DMABD）,5-sulfosalicylic acid（SSA）,morin sulfanilamide and ofloxacinand under the silane coupling agent（APS,CPS）and used for preconcentration and separation of trace amounts of metal ions from solution samples prior to their determination by inductively coupled plasma optical emission spectrometry（ICP-OES）.The separation/preconcentration conditions of analytes, which include the effects of the pH,the sample flow rate and volume,the elution condition,detection limits and precision and the interfering ions on the recovery of the analytes were investigated in detail.The accuracy of the proposed each method was checked by analyzing standard reference material with satisfactory results. Compared with untreated nanometer SiO₂ and silica gel,the modified nanometer SiO₂ and silica gel show the higher selectivity and adsorption capacities for pre-concentration and separation of trace heavy ions.（2）The new adsorbent was prepared using diethyldithiocarbamate（DDTC） Impregnated activated carbon（AC）followed by activating agent of NaOH.The modified activated carbon with diethyldithiocarbamate（DDTC）was used as an adsorbent for the solid-phase extraction（SPE）of trace amounts of Pb（Ⅱ）and Cr（Ⅲ） from solution samples prior to their determination by inductively coupled plasma optical emission spectrometry（ICP-OES）.The separation/pre-concentration conditions of analytes,which include the effects of the pH,the sample flow rate and volume,the elution condition,detection limits and precision and the interfering ions on the recovery of the analytes were investigated in detail.The accuracy of the proposed each method was checked by analyzing standard reference material with satisfactory results.Compared with untreated activated carbon,the modified activated carbon show the higher activation of adsorption and selectivity for pre-concentration and separation of trace heavy ions.（3）The imprinted and non-imprinted copolymers for Pb（Ⅱ）was obtained by a surface imprinting technique for selective solid-phase extraction（SPE）of Pb（Ⅱ）and prior to its determination by ICP-OES.The separation/pre-concentration conditions of analytes,which include the effects of the pH,the sample flow rate and volume,the elution condition,detection limits and precision and the interfering ions on the recovery of the analytes were investigated in detail with reliable and satisfactory results.The substrate selectivity of imprinted polymer and non-imprinted polymer was investigated.The results showed that the imprinted polymer exhibited much higher affinity for Pb（Ⅱ）.更多还原