The chemical elements, typically set by physico-chemical properties in solid form, can be divided in essential and toxic. The essential elements are those needed to maintain its normal physiological functions such as Zn, Fe, Co, Mg, Se. The toxic elements are those that have no function in the body such as Cd, Pb, Hg and As. An example, arsenic (As) is widely distributed in the environment being considered by the ATSDR (USA) the most toxic compound to humans. It is linked to several peripheral vascular diseases, heart, anemia and cancer. Inorganic forms, As(III) and As(V), are more toxic, being methylated to methylarsonic acid (MMA) and dimethylarsinic acid (DMA). This methylation is not constant, varying according to age, gender, ethnicity, exposure dose, pregnancy, nutritional status and genetic polymorphism, causing variations in the toxicity of the species. In humans the As-compounds are employed as medicaments for the treatment of leukemia. In animals as growth and antiparasitic drugs and, finally, they can be used as pesticides. Thus, due to their high water solubility, oral exposure is more common. Countries such as Japan, USA, Australia and the European Community are developing policy efforts (laws) and technology to evaluate the concentration of species of compounds in food (imported) and the environment. Thus, due to the increasing demands of domestic and international markets for food safety, it is essential to develop quick and simple methods for routine application in speciation analysis by HPLC-ICP-MS. Abroad, many research groups use the HPLC-ICP-MS for As speciation because it is a versatile tool with high sensitivity and selectivity. Several methods of extraction and quantification of As species in matrices such as liver, kidneys, blood, serum, urine, hair, apple, rice and marine organisms have been developed. However, in Brazil, a important food exporter, there is a deficiency in the speciation analysis of As. Therefore, this project aims to: i) develop and validate a method for separation and quantification of As(III), As(V), DMA, MMA and Arsenobetaína HPLC-ICP-MS; ii) develop a simple extraction of the species for application in routine; iii) apply the method in rice and fish samples commonly consumed in Brazil for food safety; iv) study the As uptake and metabolism of As by rice plants (Oryza sativa L.).
News published in Agência FAPESP Newsletter about the scholarship: