Organophosphorus pesticide residues in market foods in Shaanxi area, China

The aim of this study was to investigate the organophosphorus (OP) pesticide residues in market foods (cereals, vegetables, and fruits) in the Shaanxi area of China. The concentrations of eight OP pesticides were determined by gas chromatography with flame photometric detection (GC-FPD). In 18 of 200 samples, five OP pesticides, including dichlorvos, dimethoate, parathion-methyl, pirimiphos-methyl and parathion, were found in concentrations ranging from 0.004 to 0.257 mg/kg. The mean levels of dimethoate in fruits and parathion in vegetables exceeded the maximum residue limits (MRLs) allowed by the Ministry of Health, of China. Other detectable OP pesticide residues levels were below their MRLs. Demeton, diazinon and sumithion were not found in any sample. The results provide important information on the current contamination status of a key agricultural area in China, and point to the need for urgent action to control the use of some excessively applied and potentially persistent OP pesticides, such as dimethoate and parathion.