Nuclear analytical methods for trace elements and their species

我的研究主要集中在核分析、生物分析和形态形成方法的基本发展，以确定环境和毒理学感兴趣的元素的总浓度和物种特定浓度。我们开发了仪器、预浓集和放射化学中子活化分析(NAA)方法，使用短寿命和中等寿命的核素，以高精度、准确性、特异度和快速的方式测量痕量和超痕量元素的总浓度。我们还开发了特殊的分离和纯化方法来表征不同种类的元素，然后使用NAA进行测定。我们提出的研究计划由六个不同的项目组成。其中一个项目涉及确定达尔豪西大学Slowpoke-2反应堆中子通量和其他参数的特性，以开发基于k0-NAA的方法。另一个项目是评估反符合和符合-符合伽马射线光谱分析在检测短期和中期核素方面的优势。第三个项目涉及开发一种利用绿色化学通过浊点萃取从水样中同时预富集金属络合物的方法。离子交换、高效液相色谱、溶剂萃取和蒸馏方法与NAA相结合，是同时测定水样和海洋样品中各种形态的砷、锑和硒的基础。在另一个项目中，我们正在开发溶剂萃取、凝胶过滤、高效液相、反相萃取色谱以及与NAA联用的酯化反应，以分离和表征海洋鱼类和哺乳动物中潜在有毒的可提取有机卤素。我们还调查饮用水和食物中天然存在的放射性物质。我们开发了许多分析方法来研究牛奶中的各种碘。我们的研究项目提供核分析、环境、营养和毒物化学方面的本科生和研究生、博士后和来访科学家的培训。

The main focus of my research lies in the fundamental development of nuclear analytical, bioanalytical and speciation methods for the determination of total as well as species-specific concentrations of elements of environmental and toxicological interest. We develop instrumental, preconcentration and radiochemical neutron activation analysis (NAA) methods for measuring total concentrations at the trace and ultra-trace levels of elements with high precision, accuracy, specificity, and rapidity using short- and medium-lived nuclides. We also develop special separation and purification methods for the characterization of various species of elements followed by their determination using NAA. Our proposed research program consists of six different projects. One of these projects involves the characterization of the Dalhousie University SLOWPOKE-2 reactor neutron flux and other parameters for the development of k0-NAA based methods. Another project is designed to evaluate the analytical advantages of anti-coincidence and coincidence-coincidence gamma-ray spectrometry for the detection of short- and medium-lived nuclides. A third project deals with the development of a method for the simultaneous preconcentration of metal chelates from aqueous samples by cloud point extraction using green chemistry. A combination of ion exchange, liquid chromatography, solvent extraction, and distillation methods in conjunction with NAA is the basis for the simultaneous determination of various species of arsenic, antimony and selenium in aqueous and marine samples. In another project, we are developing solvent extraction, gel filtration, liquid chromatography, reversed-phase extraction chromatography, and esterification coupled to NAA for the separation and characterization of potentially toxic extractable organohalogens in marine fish and mammals. We also investigate naturally occurring radioactive materials in drinking water and foods. We develop a number of analytical methods for studying various species of iodine in milk. Our research program provides training of undergraduate and graduate students, postdoctorates, and visiting scientists in nuclear analytical, environmental, nutritional and toxicological chemistry.