title: Gas chromatographic determination of pesticide residues in malt, spent grains, wort, and beer with electron capture detection and mass spectrometry.
abstract: A method for the simultaneous determination of 9 pesticides (dinitroanilines, organophosphorus, triazoles, and pyrimidines) in several products (malt, spent grains, wort, and beer) of the beer industry is reported. Solid samples (malt and spent grains) are extracted by homogenization with a water-hexane mixture, and the pesticides are partitioned with dichloromethane. Liquid samples (wort and beer) are extracted by sonication with a hexane-dichloromethane mixture. Determination of pesticide residues was made by capillary gas chromatography with an electron capture detector (ECD). Confirmation of the compounds was performed by gas chromatography/ion trap mass spectrometry in the selected ion monitoring mode. Detection limits for GC-ECD varied from 0.2 to 5.5 pg for trifluralin and malathion, respectively. Recoveries of the pesticides from spiked samples ranged from 81.2 to 113.7% with a relative standard deviation between 3.4-7.5%. The method presents good linearity over the studied range (0.005-2 microg/mL). The proposed method is rapid and reliable and can be useful for routine monitoring during brewing.
authors.affiliation: University of Murcia, Campus Universitario de Espinardo, School of Chemistry, Department of Agricultural Chemistry, Geology, and Pedology, E-30100, Murcia, Spain.
authors.forename: Nuria
authors.initials: N
authors.lastname: Vela
authors.forename: Gabriel
authors.initials: G
authors.lastname: Pérez
authors.forename: Ginés
authors.initials: G
authors.lastname: Navarro
authors.forename: Simón
authors.initials: S
authors.lastname: Navarro
mesh_terms: D001515:Beer; D002849:Chromatography, Gas / Q000379:methods*; D002523:Edible Grain / Q000737:chemistry; D004583:Electrons; D006586:Hexanes / Q000737:chemistry; D008294:Malathion / Q000737:chemistry; D013058:Mass Spectrometry / Q000379:methods*; D008752:Methylene Chloride / Q000737:chemistry; D008956:Models, Chemical; D010573:Pesticide Residues / Q000032:analysis* / Q000737:chemistry; D010575:Pesticides / Q000737:chemistry*; D015203:Reproducibility of Results; D012997:Solvents; D014274:Trifluralin / Q000737:chemistry
chemical_list: D006586:Hexanes; D010573:Pesticide Residues; D010575:Pesticides; D012997:Solvents; D008752:Methylene Chloride; D014274:Trifluralin; D008294:Malathion