Fenitrothion determination in wheat flour

Abstract

Fenitrothion is an organophophorus insecticide of moderate toxicity to mammals, which is used in agriculture to control insects on some cultures and on stored grains. ANVISA/ Brazilian Ministry of Health established the fenitrothion maximum limit residue (MLR) of 1.0mg/kg in wheat. The aim of this investigation was to verify this compound residues in white wheat flour to comply the São Paulo State Health Programme “Programa Paulista 2006”. For this purpose a survey of fenitrothion residues was carried out in 62 flour samples from varied market sites and bakeries of São Paulo State, collected by Sanitary Surveillance Service from April to June 2006. Fenitrothion residues were determined by means of gas chromatography with flame photometric detection (GC-FPD). Recovery studies were performed at two different levels, 0.05 e 0.50mg/kg, and the mean recoveries on the established levels were between 93% - 113% and 78% - 91%, respectively. The limit of detection was estimated as 0.02mg/kg, and the limit of quantification was 0.05mg/kg. The data showed values of fenitrothion lower than the established MRL to wheat (1.0mg/kg), which corroborate the needs to establish MRL for processed products, such as wheat flour. MRLs are the basis for calculating the daily dietary consumption of pesticides. They also provide factual data for estimating the daily pesticide residue intake by a person that consumes its usual diet (Acceptable Daily Intake).