title: Method validation and dissipation kinetics of four herbicides in maize and soil using QuEChERS sample preparation and liquid chromatography tandem mass spectrometry.
abstract: A versatile liquid chromatography tandem mass spectrometry method with modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) sample preparation was developed for the determination of rimsulfuron, mesotrione, fluroxypyr-meptyl, and fluroxypyr. By adjusting the amount of graphitized carbon black, the herbicide analytes could be quantified with satisfactory recoveries in the range of 80-110%. A dissipation kinetics study conducted under open field conditions at two sites during 2014 showed first order equations with half-lives between 0.6d and 3.6d, illustrating an appropriate degree of stability and safety. The dissipation kinetics were different in the different matrices. Although the herbicides had higher initial residues in straw than those in soil, they degraded faster in straw. The terminal residues for the herbicides formulated in two water dispersible granules were all below maximum residue limits. These results not only gave insights about the analytes but also contributed to environmental protection and food safety.
authors.affiliation: Lab of Pesticide Residues and Environmental Toxicology, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, PR China. Electronic address: sevensmiling@gmail.com.
authors.forename: Nannan
authors.initials: N
authors.lastname: Pang
authors.affiliation: Lab of Pesticide Residues and Environmental Toxicology, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, PR China. Electronic address: wtloong@126.com.
authors.forename: Tielong
authors.initials: T
authors.lastname: Wang
authors.affiliation: Lab of Pesticide Residues and Environmental Toxicology, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, PR China. Electronic address: jyhu@ustb.edu.cn.
authors.forename: Jiye
authors.initials: J
authors.lastname: Hu
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D006540:Herbicides / Q000032:analysis* / Q000737:chemistry; D007700:Kinetics; D010573:Pesticide Residues / Q000032:analysis*; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis / Q000737:chemistry*; D053719:Tandem Mass Spectrometry / Q000379:methods*; D003313:Zea mays / Q000737:chemistry*
chemical_list: D006540:Herbicides; D010573:Pesticide Residues; D012987:Soil; D012989:Soil Pollutants
keywords: Dissipation kinetics; Fluroxypyr (PubChem CID: 50465); Fluroxypyr-meptyl (PubChem CID: 54745); Mass spectrometry; Mesotrione (PubChem CID: 175967); Multi-residue analysis; Pesticides; QuEChERS; Rimsulfuron (PubChem CID: 91779)