Simultaneous Analysis and Dietary Exposure Risk Assessment of Fomesafen, Clomazone, Clethodim and Its Two Metabolites in Soybean Ecosystem

Kyongjin Pang,Jiye Hu

doi:10.3390/ijerph17061951

Abstract

A commercial formulation, 37% dispersible oil suspension (DOS) (fomesafen, clomazone, and clethodim), is being registered in China to control annual or perennial weeds in soybean fields. In this paper, a liquid chromatography tandem mass spectrometry method with QuEChERS (quick, easy, cheap, effective, rugged, and safe) sample preparation was developed for the simultaneous determination of fomesafen, clomazone, clethodim, and its two metabolites (CSO and CSO2) in soybean, green soybean, and soybean straw samples. The mean recoveries of our developed method for the five analytes in three matrices were ranged from 71% to 116% with relative standard deviations (RSDs) less than 12.6%. The limits of quantification (LOQs) were 0.01 mg/kg in soybean, 0.01 mg/kg in green soybean, and 0.02 mg/kg in soybean straw while the limits of detection (LODs) ranged from 0.018 to 0.125 μg/kg for these five analytes. The highest final residual amount of CSO2 in green soybean samples (0.015 mg/kg) appeared in Anhui, and the highest in soybean straw samples was 0.029 mg/kg in Guangxi, whilst the terminal residues of fomesafen, clomazone, clethodim and CSO were lower than LOQs (0.01 mg/kg) in all samples. Furthermore, these terminal residues were all lower than the maximum residue limits (MRLs) set by China (0.1 mg/kg for fomesafen and clethodim, 0.05 mg/kg for clomazone) at harvest. Additional chronic dietary risk was evaluated using a risk quotients (RQs) method based on Chinese dietary habits. The chronic dietary exposure risk quotients were 4.3 for fomesafen, 0.12 for clomazone, and 19.3 for clethodim, respectively, which were significantly lower than 100. These results demonstrated that the dietary exposure risk of fomesafen, clomazone, and clethodim used in soybean according to good agricultural practices (GAP) was acceptable and would not pose an unacceptable health risk to Chinese consumers. These results not only offer insight with respect to the analytes, but also contribute to environmental protection and food safety.

Highlights

IntroductionThe annual productions of soybean around the world were as high as 13.15 million tons in China, 7.7 million tons in Canada, 114.59 million tons in Brazil and 119.5 million tons in USA [1], respectively
Soybean is one of the most important and widely grown crops in the world
Two UPLC-electro-spray ionization source (ESI)-MS/MS modes of negative and positive ions were compared for the five analytes of fomesafen, clomazone, clethodim, CSO, and CSO2

Summary

Introduction

The annual productions of soybean around the world were as high as 13.15 million tons in China, 7.7 million tons in Canada, 114.59 million tons in Brazil and 119.5 million tons in USA [1], respectively. The huge production, but the corresponding consumption were closely related to the use of pesticides. These pesticides are intentionally toxic towards target and non-target organisms, wherein some pesticides have been suspected to have negative effects in human health risk [2,3]. As a commercial formulation, 37% dispersible oil suspension (DOS) (fomesafen, clomazone, and clethodim) is being registered in China, and it is expected to be widely used in soybean fields to control annual. Public Health 2020, 17, 1951; doi:10.3390/ijerph17061951 www.mdpi.com/journal/ijerph

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