Residue and Dietary Risk Assessment of Glyphosate, Glufosinate-Ammonium, and Their Metabolites in Maize and Soybean

Persistent weed growing in herbicide-resistant maize and soybean fields is controlled increasingly by glyphosate (GLY) and glufosinate-ammonium (GLU). There is increasing concern that consumers may be exposed to herbicide residues. A Total of 224 samples involved supervised trials and market sampling were carried out. And the levels of GLY and GLU were determined in maize and soybean samples by UPLC MS/MS method. The residues of GLY and GLU were at a low level in all samples and ranged from <0.04 to 0.29 mg/kg and <0.04 to 0.91 mg/kg, respectively. Deterministic and probabilistic models were used to assess the dietary risk, and the highest risk quotient (RQ) values of GLY and GLU were 2.24 x 10(-4) and 3.27 x 10(-2), respectively. The RQs of GLU are significantly higher than that of GLY. Risk assessment results showed that GLY and GLU residues should not pose serious health risks to Chinese consumers.