Bitter gourd has the highest azoxystrobinon residue after open field application on four cucurbit vegetables.

Gang Guo,Xiaohan Li,Fengmao Liu,Yanli Bian,Yulin Gao

doi:10.1371/journal.pone.0203967

Abstract

The goal of this study was to select a representative cucurbit vegetable crop that contained the highest residue levels of the pesticide azoxystrobinon. To do this, we used open field application of azoxystrobinon in four cucurbit crops (cucumber, zucchini, bitter gourd, and loofah) in Beijing, Shandong, and Anhui. Liquid chromatograph-mass spectrometry/mass spectrometry (LC-MS/MS) with selected reaction monitoring was used to determine azoxystrobinon levels in each of the selected cucurbit vegetables. The azoxystrobinon limit of detection was 0.005 mg kg-1 for all samples. Recoveries of azoxystrobinon ranged from 94.2% to 107.1% at spiked levels of 0.005–0.5 mg kg-1. In field trials, the half-life of azoxystrobinon in each of the four cucurbit crops was within the range of 1.4–3.1 d. Based on these results, we recommend that bitter gourd is selected as a representative cucurbit vegetable for future studies of azoxystrobinon. The obtained residual data were also assessed for their dietary risk and results indicated that there is no chronic dietary risk in any of the four, selected cucurbit vegetables. The recommended maximum residue limit (MRL) of azoxystrobinon in this subgroup was 0.2 mg/kg.

Highlights

Cucumber (Cucumis sativus L.), zucchini (Cucurbita pepo Linn), bitter gourd (Momordica charantia L.), and loofah (Luffa cylindrica (L.) Roem.) are cultivated in many parts of the world and are especially prevalent in China
Pesticide manufacturers are not willing to spend the time and money to register their products for such crops and there are relatively few pesticide products registered for such small crops
The identification and quantification of azoxystrobin was based on high- performance liquid chromatography using electrospray ionization-tandem mass spectrometry retention periods

Summary

Introduction

Cucumber (Cucumis sativus L.), zucchini (Cucurbita pepo Linn), bitter gourd (Momordica charantia L.), and loofah (Luffa cylindrica (L.) Roem.) are cultivated in many parts of the world and are especially prevalent in China. Despite their prevalence, zucchini, bitter gourd, and loofah are all regarded as minor crops. They typically form many small, specialty crops that cover a small and scattered cultivating area and use a limited amount of pesticides Given these metrics, pesticide manufacturers are not willing to spend the time and money to register their products for such crops and there are relatively few pesticide products registered for such small crops.

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