TITLE:
Determination of Paraquat in Several Commercially Available Types of Rice
AUTHORS:
Thais Lopes Lima, Maria Aparecida Nicoletti, Camila Munhoz, Gabriel Ramos De Abreu, Julia Zaccarelli Magalhães, Esther Lopes Ricci Ricci, Paula A. Faria Waziry, Júlia Nathalia Alves da Costa, Ana Carolina Nascimento Antônio, André Rinaldi Fukushima
KEYWORDS:
Paraquat, Herbicide, Rice
JOURNAL NAME:
Food and Nutrition Sciences,
Vol.9 No.12,
December
24,
2018
ABSTRACT: Introduction: Paraquat (1,1’-dimethyl-4,4’-bipyridine-dichloride) is a herbicide used to combat weeds and improve crop productivity. Its acute toxicity can cause fatal poisoning in humans and animals and several studies have shown a strong correlation between paraquat and Parkinson’s disease. Objective: To determine the concentration of paraquat in different types of rice in Brazil. Method: Paraquat quantification is based on a complexation reaction with sodium dithionite, which generates a blueish color compound, whose absorbance was read in a spectrophotometer at the 600 nm wavelength. Results: Five samples were found to be above the maximum allowed limit, while one sample had a concentration in the upper allowed limit. The method employed did not allow quantification of black rice. Conclusion: There is a need for identification of the type of pesticide used in each examined crop as well as their respective dates of remission in order to improve the safety of agricultural practices.