Multi-user equipment (MUE) approved in Grant FAPESP project 2014/05151-0: inductively coupled plasma mass spectrometer hyphenated to an high performance liquid chromatography (HPLC-ICP-MS)

Abstract

Arsenic (As) is considered the most toxic xenobiotic according to the Agency for Toxic Substances and Disease Registry in the United States. Concerning the chemical species present in nature, inorganic As (As3+ and As5+) are the most toxic to humans and the methylated forms are less toxic (MMA - monomethyl As -, DMA - dimethyl As - and AsB - arsenobetaine) . When present in the soil, they are absorbed by the rice roots, reaching the grain. This cereal is an important food of Brazilians and almost half the world's population, therefore, a relevant route of exposure. One the one hand, the plant has mechanisms that favor the absorption of As by roots, especially As3+ when cultivated under flooded conditions. On the other hand, also has defense mechanisms such as phytochelatins and efflux of As. It is known that the rice consumed in Brazil has an average concentration of > 222 ng g-1 which about 60 % is inorganic, representing a risk to health when compared to the maximum tolerable value of 10 µg l-1 in potable water. The main producing states are Rio Grande do Sul and Santa Catarina, which uses the cultivation at flooded conditions. Furthermore, there is currently an intense discussion among participants of the Codex Alimentarius about the maximum levels of As in rice, as well as methods of speciation and practices to mitigate this contamination. Therefore, this project aims to develop methods of chemical speciation, risk assessment of the consumption of rice and its derivatives regarding As contamination, to investigate Brazilian cultivars in relation their predilection for As, development of method for trapping volatile As for evaluation of their presence in soils of rice paddies and, finally, to study mitigation through polishing, cooking and (bio)remediation using fungi isolated from the rhizosphere of Brazilian rice. Through this project we hope to evaluate the risk of rice consumption, to reduce the As contamination in the grains aggregating nutritional value and create human resources to work on chemical analysis and food safety. (AU)