胶东地域环境中痕量贵金属元素的分析研究

Jiaodong peninsula abounds in fruit, such as apple, cherry, etc, and its inshore is important seafood aquaculture. Meanwhile, there are many gold mine in this region, where gold reserves accounted for one quarter of the national total number. However, the scientific research has not been reported for the influence of the gold, silver and platinum group metals in jiaodong region environment. We plan to make the jiaodong region as the object of investigation, and collect representative samples in this region, such as the soil and fruit on land, the sea water, algae, shellfish and sediment in inshore. Afterwards, we want to develop novel analytical methods for trace precious metals detection based on multiple sample pre-treatment technology combined with the total reflection X-ray fluorescence analysis (TXRF) and the thin layer-XRF analysis technology, which has been established by our group. We focus on the functional modification of graphene oxide and carbon nanotubes nanomaterials, and find out the suitable method for the enrichment and separation of trace metals in the sample above. At the same time, dispersive liquid-liquid microextraction (DLLME) method which is for separation and enrichment and electrodeposition technology are used to detect precious metals in the complex system such as the seawater. Thin layer-XRF analysis method is applied for the determination of multiple of trace metal elements in samples. The rich data of precious metal’s distributions in typical Jiaodong environment area could be obtained and it will lay a foundation for further research of the ecological impact to the environment with precious metal elements in jiaodong region.

胶东半岛盛产苹果、大樱桃等果品，近海也是重要的海产品养殖生产区，同时金矿密集，黄金矿藏占全国1/4，但金、银和铂族贵金属元素对于胶东地域环境的影响问题尚未见系统研究报道。本课题拟以胶东地域为考察对象，从陆地到近海环境中选择如土壤、水果，和近海中海水、海藻、贝类及海底沉积物等有代表性的样品，在课题组已建立的全反射X射线荧光分析（TXRF）和薄样技术-XRF分析技术基础上，综合多种样品前处理技术，建立痕量贵金属元素分析方法。以氧化石墨烯、碳纳米管等纳米材料为重点，进行功能化改性，找出适合上述样品中痕量贵金属分离富集的方法；同时试验分散液相微萃取（DLLME）手段用于分离富集和电沉积技术用于海水等复杂体系中贵金属的分离富集，应用薄样技术-XRF分析方法，测定样品中多种痕量贵金属元素。以期获得关于胶东典型区域环境中贵金属分布的丰富数据，为进一步研究胶东地区贵金属元素对环境生态影响打下基础。

胶东地区金矿遍布，贵金属元素对环境影响问题值得关注，本项目以该地域环境样品为主要对象，以分离富集方法为重点，研究痕量贵金属为主的分析问题，主要工作为：.①.建立样品采集和以微波消解为主预处理方法，基本做到待测元素无污染和无损失。.②.选择以纳米材料为主的数种材料为基础，进行功能化改性，经过材料表征后，开展富集分离金等贵金属元素试验，结合薄样-XRF分析和ICP-MS 等方法测定，取得较好效果。主要有：制备2-氨基-5-巯基-1,3,4噻二唑和L-半胱氨酸修饰硅胶，用于分离富集痕量金，富集倍数分别为125，100，检出限均为0.017 µg/mL；合成L-半胱氨酸修饰氧化石墨烯用于分离富集金元素，检出限0.035 µg/mL；利用三乙烯四胺合成三维石墨烯，以海水为基体进行金和钯吸附，性能较好；制备了巯基改性的石墨烯/多壁碳纳米管气凝胶（SH-GNAs）用于金的分离富集，吸附最接近二级动力学模型。.③.结合薄样-XRF测定技术，采用分散液液微萃取（DLLME）分离富集痕量贵金属，以TMK作为络合剂，建立了痕量金的检测方法，检出限为0.04 μg•L-1 ，富集倍数为124；双硫腙作络合剂对痕量银的检测，富集倍数136；PAN为络合剂同时检测金与钯，富集倍数分别为143、136。.④.开展了电沉积技术分离富集微量金属元素实验，以水样为基体的铜离子沉积率在1.26 %～2.06 %之间，随后实验了微量金的分离富集可行性。 .⑤.材料改性应用于多种离子检测方法研究，主要是：双金属纳米粒子/L-半胱氨酸改性氧化石墨烯传感器测定痕量Fe(III)；聚邻苯二胺改性氧化石墨烯负载铋金属电化学传感器测定痕量Pb(II)；基于碳纳米管/二硫化钼纳米片复合材料电化学传感器检测Cu2+；合成巯基修饰的金掺杂氧化石墨烯建立电化学传感器，检测亚硝酸盐。结果令人满意。.⑥.改进课题组的ED-XRF仪，采用薄样技术和内标法结合测定，成功应用于上述多项实验，检测部分实际样品中贵金属含量，获得有价值的数据。.部分成果发表在正式学术期刊上，SCI收录5篇。.