title: Direct determination of paclobutrazol residues in pear samples by liquid chromatography-electrospray tandem mass spectrometry.
abstract: A rapid and sensitive liquid chromatography/electrospray ionization/tandem mass spectrometry (LC-ESI-MS-MS) method has been developed for the determination of the plant growth regulator paclobutrazol in pear samples. Extraction was performed with methanol by using a high-speed blender Ultra-Turrax, and 10 microL of pear extract was directly injected in the LC-ESI-MS-MS system without any previous sample treatment. The highest sensitivity of the method was achieved under MS-MS conditions obtaining a limit of detection of 0.7 microg/kg and a quantification limit of 5 microg/kg, with a run time of only 5.5 min. Recoveries for paclobutrazol from spiked pear samples at 0.005, 0.05, and 0.5 mg/kg were around 82-102% with relative standard deviations between 2 and 7%. The method was applied to real treated and untreated samples of pears, using quality control samples as a evaluation of the method reliability. Two MS-MS transitions were selected, one for quantification (294 > 70) and the other for confirmation of the analyte (296 > 70). All the experiments were performed in compliance with good laboratory practices.
authors.affiliation: Analytical Chemistry, Experimental Sciences Department, University Jaume I, E-12071, Castellón, Spain.
authors.forename: Juan V
authors.initials: JV
authors.lastname: Sancho
authors.forename: Oscar J
authors.initials: OJ
authors.lastname: Pozo
authors.forename: Tatiana
authors.initials: T
authors.lastname: Zamora
authors.forename: Susana
authors.initials: S
authors.lastname: Grimalt
authors.forename: Félix
authors.initials: F
authors.lastname: Hernández
mesh_terms: D002851:Chromatography, High Pressure Liquid; D004350:Drug Residues / Q000032:analysis*; D005638:Fruit / Q000737:chemistry*; D031989:Pyrus / Q000737:chemistry*; D011786:Quality Control; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization; D014230:Triazoles / Q000032:analysis*
chemical_list: D014230:Triazoles; C053370:paclobutrazol