Multiresidue analysis of pesticides and dietary risk assessment of Coix seed by UPLC-MS/MS

The Coix seed is a plant known for both its medicinal and nutritional properties. However, research on controlling diseases and pests affecting Coix seeds remains limited. In this study, a multi-residue analysis and dietary risk assessment method for 28 fungicides in Coix seed was developed using UPLC-MS/MS combined with an enhanced QuEChERS approach. Pesticide residues were analyzed in various types of Coix seed, with three pesticides being detected in the samples. Azoxystrobin had the highest detection rate at 8.8 %, followed by prothioconazole at 7.4 %, and thiophanate-methyl at 1.5 %. The detection rates for big Coix seed (ACS), small Coix seed (BCS), glutinous Coix seed (CCS), and red Coix seed (DCS) were found to be 12.5 %, 27.5 %, 6.7 % and 19.2 % respectively. Importantly, all pesticide residue concentrations were below maximum residue levels (MRL). Dietary risk assessments indicated that the risk posed by pesticide residues is low and unlikely to pose a threat to human health in the short term. This study provides technological recommendations to improve the scientific and rational monitoring and management of pesticide applications.