【作者】 谢发之；

【导师】 谢增鸿；

【作者基本信息】 福州大学 ， 分析化学， 2004， 硕士

【摘要】 在过去的二十年中，利用固相萃取技术从环境样品中萃取分离富集痕量重金属离子越来越受到人们的重视，应用日益广泛。在固相萃取技术的研究中,固萃剂是影响分析灵敏度和选择性的重要因素，所以对新型固萃剂的探索和研究十分活跃。 本文共分为四章。其中第一章为文献综述，在大量文献调研的基础上，介绍固相萃取试剂的研究进展及其对金属离子的固相萃取原理，最后对重金属离子固萃剂的研究进行了展望。在第二章中，合成了基于硅胶的以硫代乙酰胺为螯合功能基团的固萃剂TASG。利用紫外漫反射光谱，拉曼光谱和元素分析对合成的TASG进行了表征，考察了TASG的物理化学性能。采用FAAS作为检测手段，系统地研究了TASG在静态和动态条件下对重金属离子Pb(II)、Cu(II)、Cd(II)的吸附性能。定量回收Pb(II)、Cu(II)、Cd(II)的最佳pH范围分别为：4.0～8.0；2.0～7.0；5.0～10.0。Pb(II)、Cd(II) 可以分别被3.0mol.L－1和0.1mol.L-1的盐酸溶液或硝酸溶液洗脱；Cu(II) 可以被2.5％的硫脲溶液洗脱。TASG对Pb(II)、Cu(II)、Cd(II)的吸附容量分别为19.76 mg.g-1，16.35mg.g-1和12.50 mg.g-1；Pb(II)的预富集因子为300，Cu(II)、Cd(II)为200。用于实际水样中上述离子的分离富集与测定，结果满意。在第三章中，合成了基于硅胶的以3,4,5-三羟基苯甲酸为螯合功能基团的固萃剂GASG。利用紫外漫反射光谱，红外漫反射光谱和元素分析对合成的GASG进行了表征，考察了GASG的物理化学性能。采用FAAS作为检测手段，系统研究GASG在静态和动态条件下对重金属离子Pb(II)、Cu(II)、Cd(II)、Ni(II)的吸附性能。定量回收Pb(II)、Cd(II)、Cu(II)、Ni(II)的最佳pH范围分别为：3.0～7.0；6.0～10.0；4.0～10.0；6.0～10.0。Pb(II)、Cd(II)、Cu(II)可以被0.05mol.L-1的盐酸溶液或硝酸溶液洗脱；Ni(II) 可以被0.1mol.L-1的盐酸溶液或硝酸溶液洗脱。GASG对Pb(II)、Cu(II)、Cd(II)、Ni(II)的吸附容量分别为12.63 mg.g-1，15.38mg.g-1，6.09mg.g-1和4.50 mg.g-1；Cu(II)、Pb(II)、Ni(II)的预富集因子为200， Cd(II)为100。将其应用于实际水样中Pb(II)、Cu(II)、Cd(II)、Ni(II)萃取富集，取得较好结果。在第四章中，设计了一种手动控制进样速度的快速萃取分离富集Pb(II)离子的固相萃取装置。该装置由5ml一次性注射器、接口和萃取分离富集微柱组成，以巯基葡聚糖凝胶为固萃剂，系统研究了Pb(II)在该萃取装置上的萃取性能，根<WP=3>据与其他金属离子吸附性能的差异，在选定的pH条件下(pH=3.30)，5ml样品液30秒内注射过柱，5ml2mol/L的盐酸溶液以相同的流速注射洗脱，可以实现了对Pb(II)的选择性分离富集，Pb(II)的平均回收率可以达到96.95％，RSD=3.33％（n＝22），预富集因子约为200。应用于蔬菜中铅的快速分离与富集，取得较好的结果。更多还原

【Abstract】 In the past twenty years,the use of solid phase extraction techniques has become increasingly popular for separation and preconcentration of trace elemens in environmental samples. The choice of solid-phase extractant is the decisive factor that affects analytical sensitivity and selectivity. This dissertation consists of the following four chapters. In the first chapter, the recent development of solid phase extractant and its principle on separation and preconcentration of trace elements were reviewed, in addition, its future development was also discussed. In chapter two, a new chelating matrix TASG was prepared with thioacetamide anchored in silica gel modified withγ-aminopropyltriethoxysilane. By diffuse reflectance UV-VIS spectroscopy, raman spectroscopy,elemental analysis, its characteristics was investigated,and used for the separation and preconcentration of Pb(II),Cu(II) and Cd(II) through batch method and column method prior to their determination by flame atomic absorption spectrometry(FAAS). The optimum pH ranges for quantitative sorption are 4.0～8.0,2.0～7.0 and 5.0～10.0 for Pb(II),Cu(II) and Cd(II), respectively. Pb(II) and Cd(II) can be desorbed with 3mol.L－1 and 0.1mol.L-1 HCl/HNO3 ,and Cu(II) can be desorbed with 2.5% thiourea. The sorption capacity of the matrix has been found to be 19.76 ,16.35 and 12.50 mg.g-1 for Pb(II),Cu(II) and Cd(II), respectively, with the preconcentration factor of ~300 for Pb(II) and ~200 for Cu(II) and Cd(II).The FAAS was used to determine these metal ions in water sampls after their enrichment with the present matrix. In chapter three, a new chelating matrix GASG has been prepared by immobilizing 3,4,5-trihydroxybenzoic acid(gallic acid) on silica gel.After characterizing the matrix with diffuse reflectance UV-VIS spectroscopy,diffuse reflectance infrared fourier transformation (DRIFT) and elemental analysis,it has been used to separation and preconcentration of Pb(II),Cu(II),Cd(II) and Ni(II) through batch method and column method prior to their determination by flame atomic absorption spectrometry. The optimum pH ranges for quantitative sorption are 3.0～7.0,6.0～10.0,4.0～10.0 and 6.0～10.0 for Pb(II), Cd(II),Cu(II) and Ni(II), <WP=5>respectively. All the heavy meatals can be desorbed with 0.05mol.L-1HCl/HNO3 but 0.1mol.L-1HCl/HNO3 for Ni(II). The sorption capacity for these heavy metal ions is in range of 4.50-15.30mg.g-1 of the present chelating matrix.Preconcentrtion factors of 200,200,200 and 100 for Pb(II),Cu(II), Ni(II) and Cd(II),respectively. In water samples all these heavy metal ions were enriched with GASG and determinated with FAAS. The satisified results were obtained.In chapter four, a new solid phase extractor which was composed of a 5ml single-use syringe, an interface and a micro-colume was designed for separation and concentration of Pb(II). The flow rates of samples were controlled manually by a single-use syringe. 5ml sample solution (pH=3.30) was injected into the micro-column filled with SDG and through the micro-column in 30 seconds, and then the adsorbed Pb(II) was eluted by 5ml 2mol/LHCl at the same flow rate.The average recovery of Pb(II) up to 96.95% ,RSD＝3.33％（n＝22）, pre-concentration factor of 200 for Pb(II) was obtained.It can be applied to separation and concentration of a large volume of sample solution contained trace amount of Pb(II) . It was satisfied to be applied to separate and enrich trace amount of Pb(II) in vegetables prior to its determination by FAAS.更多还原