| Strobilurin fungicide is effective against almost all fungal diseases and is the most popular fungicide in the global fungicide market.However,after application,the pesticide will not only remain in the agricultural products directly,but also spread into the air,soil and rivers through migration,transformation and accumulation,and finally cause harm to different levels of organisms through the food chain,thus affecting human health.At present,there are few detection methods for a variety of strobilurin fungicides in fruits,vegetables and surface water,especially for the self-developed Methoxyacrylate fungicides in China.Therefore,it is necessary to establish a rapid,efficient and accurate trace detection method which can simultaneously detect a variety of strobilurin fungicides in a variety of matrices.In this study,9 kinds of common strobilurin fungicides including picoxystrobin,fluoxastrobin,e-metominostrobin,orysastrobin,trifloxystrobin,dimoxystrobin,kresoxim-methyl,pyraclostrobin,azoxystrobin and 5 kinds of strobilurin fungicides independently developed in China including coumoxystrobin,triclopyricarb,fenaminstrobin,pyraoxystrobin,enestroburin were selected as the research objects:(1)QuEChERS-LC-MS/MS method was established for the determination of 14strobilurin fungicides in 11 representative fruit and vegetable crops,including watermelon,apple,grape,mandarin,plum,nectarine,tomato,cucumber,cabbage,pepper and potato.14 strobilurin fungicides showed a good linear relationship in the range of 0.1~100μg/kg,R~2 was greater than 0.9995,the recovery of 5,10,100μg/kg in watermelon,tomato and cucumber substrate was 61.2%~105.3%,LODs was0.01~2.00μg/kg,LOQs was 0.04~6.66μg/kg.The LODs and LOQs of 14 strobilurin fungicides were 0.01~5.11μg/kg and 0.02~17.04μg/kg respectively.(2)A method for the determination of 14 strobilurin fungicides in surface water by SPE-LC-MS/MS was established.14 kinds of strobilurin fungicides showed a good linear relationship in the range of 0.5~200μg/kg,and R~2 was greater than 0.998.Under the concentration of 5,10 and 100 ng/L,the recovery of 14 kinds of strobilurin fungicides was 62.1%~110.0%,LODs was 0.003~0.30 ng/L,and LOQs was 0.01~1.00ng/L.(3)11 kinds of fruits and vegetables were randomly selected from 3 supermarkets and 3 agricultural markets in Beijing.The residual concentration of 14 strobilurin fungicides in 11 kinds of fruits and vegetables ranged from 0.02 to 59.13μg/kg,that of supermarket samples ranged from 0.02 to 59.13μg/kg,and that of agricultural market samples ranged from 0.02 to 17.92μg/kg.The detection rates of fungicides in supermarket and farmer’s market samples were 37.6%and 35.7%,and 9 kinds of strobilurin fungicides were detected in supermarket and farmer’s market samples.The residues of 14 strobilurin fungicides in surface water were analyzed at 10 sites from upstream to downstream along the Qinghe River in Beijing.In 10 river water samples,9 kinds of strobilurin fungicides were detected,and the residual concentration was0.02~4.50 ng/L.(4)The risk of chronic and acute dietary intake of Methoxyacrylate fungicide residues in fruits and vegetables was assessed.Among 11 kinds of fruits and vegetables,the risk of chronic dietary intake(%ADI)of strobilurin fungicides residues was0.0001%~0.0937%,with an average of 0.0132%,far less than 100%;the risk of acute dietary intake(%ARfD)of picoxystrobin and pyraclostrobin in apples,grapes,plums,nectarines and tomatoes was 0.000002%~0.439%,far less than 100%.It indicated that both chronic and acute dietary intake risks were acceptable. |
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