title: Determination of imidacloprid, metalaxyl, myclobutanil, propham, and thiabendazole in fruits and vegetables by liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry.
abstract: Imidacloprid, metalaxyl, myclobutanil, propham, and thiabendazole have been simultaneously determined in strawberries, oranges, potatoes, pears, and melons by matrix solid-phase dispersion (MSPD) followed by liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry (LC-APCI-MS) in positive-ion mode. The samples were homogenized with C8 bonded silica as MSPD sorbent, placed in a glass column, and eluted with dichloromethane. Chromatographic separation of the compounds was achieved on a reversed-phase LC column using a methanol-ammonium formate (50 mmol L(-1)) gradient as a mobile phase. Samples were screened by monitoring the protonated molecular ion at m/z 256 for imidacloprid, 280 for metalaxyl, 289 for myclobutanil, and 202 for thiabendazole, and the main fragment at m/z 138 for propham. Positive samples were confirmed by multiple-ion monitoring. The repeatability (<20%) and recovery (>57%) of the method were good, and limits of detection (<0.05 mg kg(-1)) were adequate.
authors.affiliation: Laboratori de Bromatologia i Toxicologia, Facultat de Farmàcia, Universitat de Valencia, Spain.
authors.forename: X
authors.initials: X
authors.lastname: Pous
authors.forename: M J
authors.initials: MJ
authors.lastname: Ruíz
authors.forename: Y
authors.initials: Y
authors.lastname: Picó
authors.forename: G
authors.initials: G
authors.lastname: Font
mesh_terms: D000969:Antinematodal Agents / Q000032:analysis; D002219:Carbamates / Q000032:analysis; D002853:Chromatography, Liquid; D005638:Fruit / Q000737:chemistry*; D006540:Herbicides / Q000032:analysis; D007093:Imidazoles / Q000032:analysis; D007306:Insecticides / Q000032:analysis; D013058:Mass Spectrometry; D000073943:Neonicotinoids; D009574:Nitro Compounds; D010575:Pesticides / Q000032:analysis*; D048448:Phenylcarbamates; D012680:Sensitivity and Specificity; D013827:Thiabendazole / Q000032:analysis; D014675:Vegetables / Q000737:chemistry*
chemical_list: D000969:Antinematodal Agents; D002219:Carbamates; D006540:Herbicides; D007093:Imidazoles; D007306:Insecticides; D000073943:Neonicotinoids; D009574:Nitro Compounds; D010575:Pesticides; D048448:Phenylcarbamates; C082359:imidacloprid; D013827:Thiabendazole; C100175:propham