title: Degradation kinetics and pathways of spirotetramat in different parts of spinach plant and in the soil.
abstract: Spirotetramat is a new pesticide against a broad spectrum of sucking insects and exhibits a unique property with a two-way systemicity. In order to formulate a scientific rationale for a reasonable spray dose and the safe interval period of 22.4 % spirotetramat suspension concentrate on controlling vegetable pests, we analyzed degradation dynamics and pathways of spirotetramat in different parts of spinach plant (leaf, stalk, and root) and in the soil. We conducted experimental trials under field conditions and adopted a simple and reliable method (dispersive solid phase extraction) combined with liquid chromatography-triple quadrupole tandem mass spectrometry to evaluate the dissipation rates of spirotetramat residue and its metabolites. The results showed that the spirotetramat was degraded into different metabolite residues in different parts of spinach plant (leaf, stalk, and root) and in the soil. Specifically, spirotetramat was degraded into B-keto, B-glu, and B-enol in the leaf; B-glu and B-enol in the stalk; and only B-enol in the root. In the soil where the plants grew, spirotetramat followed a completely different pathway compared to the plant and degraded into B-keto and B-mono. Regardless of different degradation pathways, the dissipation dynamic equations of spirotetramat in different parts of spinach plant and in the soil were all based on the first-order reaction dynamic equations. This work provides guidelines for the safe use of spirotetramat in spinach fields, which would help prevent potential health threats to consumers.
authors.affiliation: Joint International Research Laboratory of Agriculture and Agri-Product Safety, Yangzhou University, Yangzhou, Jiangsu, 225009, Peoples Republic of China. cxj@yzu.edu.cn.|School of Horticulture and Plant Protection, Yangzhou University, Yangzhou, Jiangsu, 225009, China. cxj@yzu.edu.cn.
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Chen
authors.affiliation: Joint International Research Laboratory of Agriculture and Agri-Product Safety, Yangzhou University, Yangzhou, Jiangsu, 225009, Peoples Republic of China.|School of Horticulture and Plant Protection, Yangzhou University, Yangzhou, Jiangsu, 225009, China.
authors.forename: Zhiyuan
authors.initials: Z
authors.lastname: Meng
authors.affiliation: Joint International Research Laboratory of Agriculture and Agri-Product Safety, Yangzhou University, Yangzhou, Jiangsu, 225009, Peoples Republic of China.|Testing Center of Yangzhou University, Yangzhou University, Yangzhou, Jiangsu, China.
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Joint International Research Laboratory of Agriculture and Agri-Product Safety, Yangzhou University, Yangzhou, Jiangsu, 225009, Peoples Republic of China.|School of Horticulture and Plant Protection, Yangzhou University, Yangzhou, Jiangsu, 225009, China.
authors.forename: Haotian
authors.initials: H
authors.lastname: Gu
authors.affiliation: Joint International Research Laboratory of Agriculture and Agri-Product Safety, Yangzhou University, Yangzhou, Jiangsu, 225009, Peoples Republic of China.|School of Horticulture and Plant Protection, Yangzhou University, Yangzhou, Jiangsu, 225009, China.
authors.forename: Yajun
authors.initials: Y
authors.lastname: Ren
authors.affiliation: Joint International Research Laboratory of Agriculture and Agri-Product Safety, Yangzhou University, Yangzhou, Jiangsu, 225009, Peoples Republic of China.|Testing Center of Yangzhou University, Yangzhou University, Yangzhou, Jiangsu, China.
authors.forename: Chunliang
authors.initials: C
authors.lastname: Lu
mesh_terms: D001372:Aza Compounds / Q000378:metabolism* / Q000493:pharmacokinetics; D002853:Chromatography, Liquid; D007306:Insecticides / Q000032:analysis / Q000378:metabolism*; D007700:Kinetics; D013058:Mass Spectrometry; D010573:Pesticide Residues / Q000032:analysis*; D018515:Plant Leaves / Q000737:chemistry / Q000378:metabolism*; D018517:Plant Roots / Q000737:chemistry / Q000378:metabolism*; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis / Q000378:metabolism*; D018724:Spinacia oleracea; D013141:Spiro Compounds / Q000378:metabolism* / Q000493:pharmacokinetics; D014675:Vegetables
chemical_list: D001372:Aza Compounds; D007306:Insecticides; D010573:Pesticide Residues; D012987:Soil; D012989:Soil Pollutants; D013141:Spiro Compounds; C570705:spirotetramat
keywords: Metabolites; Residue; Spinach plant; Spirotetramat