title: Residue level, persistence and safety of spirodiclofen-pyridaben mixture in citrus fruits.
abstract: A sample pretreatment method was established to analyze the residues of spirodiclofen-pyridaben mixture in citrus fruits using ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS). A mixed formulation of 27% spirodiclofen-pyridaben suspension concentrates was sprayed on citrus in field conditions at 1- or 1.5-fold recommended dose. The dissipation of spirodiclofen-pyridaben mixture in whole citrus follows the first-order dynamic equation with half-lives of 4.56-13.1d at three locations. Residues of spirodiclofen-pyridaben mixture are mainly distributed in peel, followed by whole citrus and pulp. Risk assessment showed that spirodiclofen exerts much higher chronic risk than acute risk, while pyridaben exerts relatively lower chronic risk than acute risk. However, both chronic and acute risks of this mixed pesticide in citrus fruits are relatively low to humans irrespective of dosages, frequency of applications, and pre-harvest intervals. The residue dynamics information will support label-claim for use of this mixed pesticide in citrus fruits.
authors.affiliation: Laboratory of Quality & Safety Risk Assessment for Citrus Products (Chongqing), Ministry of Agriculture, Citrus Research Institute, Southwest University, Chongqing 400712, China; College of Horticulture and Landscape Architecture, Southwest University, Chongqing 400715, China.
authors.forename: Dali
authors.initials: D
authors.lastname: Sun
authors.affiliation: Laboratory of Quality & Safety Risk Assessment for Citrus Products (Chongqing), Ministry of Agriculture, Citrus Research Institute, Southwest University, Chongqing 400712, China.
authors.forename: Yanmei
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Laboratory of Quality & Safety Risk Assessment for Citrus Products (Chongqing), Ministry of Agriculture, Citrus Research Institute, Southwest University, Chongqing 400712, China; National Citrus Engineering Research Center, Citrus Research Institute, Southwest University, Chongqing 400712, China.
authors.forename: Junxiao
authors.initials: J
authors.lastname: Pang
authors.affiliation: College of Horticulture and Landscape Architecture, Southwest University, Chongqing 400715, China.
authors.forename: Zhiqin
authors.initials: Z
authors.lastname: Zhou
authors.affiliation: Laboratory of Quality & Safety Risk Assessment for Citrus Products (Chongqing), Ministry of Agriculture, Citrus Research Institute, Southwest University, Chongqing 400712, China; National Citrus Engineering Research Center, Citrus Research Institute, Southwest University, Chongqing 400712, China. Electronic address: jiaobining@cric.cn.
authors.forename: Bining
authors.initials: B
authors.lastname: Jiao
mesh_terms: D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000737:chemistry; D002957:Citrus / Q000737:chemistry*; D005638:Fruit / Q000737:chemistry*; D011724:Pyridazines / Q000737:chemistry*; D018570:Risk Assessment; D013141:Spiro Compounds / Q000737:chemistry*
chemical_list: D011724:Pyridazines; D013141:Spiro Compounds; C428725:pyridaben; C508135:spirodiclofen; D015107:4-Butyrolactone
keywords: Mixed pesticide; Pyridaben; Residue behavior; Risk assessment; Spirodiclofen