title: Determination of mepiquat chloride residues in cotton and soil by liquid chromatography/mass spectrometry.
abstract: A liquid chromatographic/mass spectrometric (LC/MS) method is reported for the determination of the onium-type plant growth regulator mepiquat chloride in cotton and soil. The pesticide was extracted from the sample with ethanol and water containing 2% NH4Cl. The extract was cleaned up on a solid-phase extraction C18 column, and the pesticide was determined by LC/MS. The average recoveries were 85.9-93.8, 81.3-91.7, and 78.1-94.7%, with corresponding relative standard deviations of 3.4-9.6, 3.7-12.3, and 4.0-9.8%, from soil, cotton leaves, and cotton seeds, respectively. A coefficient of determination of R2 = 0.9964 was obtained for the analyte calibration graph, from 0.05 to 100 microg/mL. Decision limits, CCalpha, and detection capability, CCbeta, were calculated. Electrospray ionization LC/MS in the positive-ion mode (ESI+) was used to detect mepiquat chloride in extracts of soil, cotton leaves, and cotton seeds. The ion at m/z 114 in the mass spectrum was monitored.
authors.affiliation: Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Key Laboratory of Pesticide Chemistry and Application Technology, Ministry of Agriculture, Beijing, People's Republic of China.
authors.forename: Xin-Gang
authors.initials: XG
authors.lastname: Liu
authors.forename: Feng-Shou
authors.initials: FS
authors.lastname: Dong
authors.forename: Shuo
authors.initials: S
authors.lastname: Li
authors.forename: Yong-Quan
authors.initials: YQ
authors.lastname: Zheng
mesh_terms: D002851:Chromatography, High Pressure Liquid; D004784:Environmental Monitoring; D003368:Gossypium / Q000737:chemistry*; D007202:Indicators and Reagents; D013058:Mass Spectrometry; D010573:Pesticide Residues / Q000032:analysis; D010880:Piperidines / Q000032:analysis*; D010937:Plant Growth Regulators / Q000032:analysis*; D018515:Plant Leaves / Q000737:chemistry; D012015:Reference Standards; D012639:Seeds / Q000737:chemistry; D012987:Soil / Q000032:analysis*; D012996:Solutions
chemical_list: D007202:Indicators and Reagents; D010573:Pesticide Residues; D010880:Piperidines; D010937:Plant Growth Regulators; D012987:Soil; D012996:Solutions; C049449:mepiquat