Determination and Dietary Intake Risk Assessment of 35 Pesticide Residues in Cowpea (Vigna Unguiculata L. Walp) from Hainan Province, China

Abstract

The presence of pesticide residues in cowpea raises serious health concerns. In this study, a novel, sensitive, high-performance method was developed to simultaneously analyse the residues of 35 pesticides in cowpea samples from growing areas in Hainan provinces of China, from November in 2018 and June in 2021, using modified QuEChERS sample pretreatment coupled with gas chromatography-tandem mass spectrometry (GC-MS/MS). The limits of detection (LOD) and quantification (LOQ) values of 35 pesticides in the cowpea matrix ranged from 0.3 µg/kg to 2.5 µg/kg and 1.0 µg/kg to 8.0 µg/kg, respectively. Twenty-seven different pesticides were detected, and twelve of them were banned pesticides on legumes in China. Residues for ten pesticides in 17.1% of the samples exceeded their MRLs with the highest exceedance of 380%, 80.8% of samples contained one or more pesticide residues, and the most frequently detected pesticide was chlorfenapyr with a detection rate of 46.3%. In addition, the pesticide triazophos was detected through different years and regions. Furthermore, the chronic dietary exposure risk (%ADI) of the detected pesticides showed less than 100% in Chinese people of different age groups, which was evaluated by the national estimated acceptable daily intake.