Trace element analysis and speciation of selenium, arsenic and gold in biological materials

Methods for determination and speciation of inorganic and organic selenium in complex matrices involving, inductively-coupled plasma mass spectrometry (ICP-MS), inductively-coupled plasma atomic emission spectrometry (ICP-AES) and high performance liquid chromatography (HPLC) were developed. Selenium species were separated and detected by mixed-mode weak anion exchange and reversed-phase stationary phases with ICP-MS and ICP-AES detection. Selenium-containing nutritional supplements, wheat flour and selenized yeast, were analyzed and the major selenium species were identified and quantified by HPLC-ICP-MS equipped with a dynamic reaction cell (DRC). The quantification response factors for different selenium and sulfur compounds, analyzed by DRC-ICP-MS and ICP-AES were determined. Possible reasons for the obtained results were discussed. The effects of arsenic and selenium added simultaneously to the growth media of Helianthus annus (sunflowers), red sunflowers and Eichhornia crassipes (water hyacinths) were determined with respect to accumulation and metabolism. Total selenium and arsenic in shoots and roots was determined. Quantification of the selenium and arsenic species in E. crassipes by HPLC-ICP-MS and HPLC-ICP-AES was also performed. An accurate and reliable method was developed for the determination of functionalized gold nanoparticles in hepatocarcinoma cell tissues and rat brain material by ICP-MS. A comparison between the gold accumulated in cell and brain tissues treated with neutral, positive and negative functionalized gold nanoparticles was performed