title: Analysis of alternariol and alternariol monomethyl ether on flavedo and albedo tissues of tangerines (Citrus reticulata) with symptoms of alternaria brown spot.
abstract: A method was developed for the quantification of alternariol and alternariol monomethyl ether on tangerines with and without symptoms of Alternaria brown spot disease. The method employs solid-phase extraction for cleanup, followed by high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) for detection. This method was validated on flavedo (exocarp or epicarp, exterior yellow peel) and on albedo tissue (mesocarp, interior white peel). An excellent linearity over a range of 0.50-20.0 mg/kg was achieved, with r2 >or= 0.997. The limits of detection (LOD) and quantification (LOQ) were fewer than 0.13 and 0.50 microg/kg, respectively. The relative standard deviations (RSDs) were <or=14.4% during the validation. The levels of these mycotoxins on flavedo of fruits with symptoms vary from 2.54 +/- 0.24 to 17.40 +/- 1.05 mug/kg. Surprisingly, neither alternariol nor altenariol monomethyl ether was detected on albedo tissues, suggesting that flavedo works as a barrier for such substances.
authors.affiliation: Laboratório de Espectrometria de Massas, Departamento de Química, Universidade Federal de São Carlos-UFSCar, Rodovia Washington Luiz, São Carlos, São Paulo, Brazil.
authors.forename: Rodrigo F
authors.initials: RF
authors.lastname: Magnani
authors.forename: Gezimar D
authors.initials: GD
authors.lastname: De Souza
authors.forename: Edson
authors.initials: E
authors.lastname: Rodrigues-Filho
mesh_terms: D000528:Alternaria; D002851:Chromatography, High Pressure Liquid; D002957:Citrus / Q000737:chemistry*; D005638:Fruit / Q000737:chemistry*; D007783:Lactones / Q000032:analysis*; D013058:Mass Spectrometry; D009183:Mycotoxins / Q000032:analysis; D010935:Plant Diseases / Q000382:microbiology*
chemical_list: D007783:Lactones; D009183:Mycotoxins; C005197:alternariol; C018206:alternariol monomethyl ether