title: Multiresidue determination of carbamate, organochlorine, organophosphorus, and dicarboximide pesticides in lettuce by GC/MS.
abstract: An extraction method based on matrix solid-phase dispersion was developed to determine pirimicarb, methyl parathion, malathion, procymidone, alpha-endosulfan and beta-endosulfan in lettuce using gas chromatography-mass spectrometry. The best results were obtained using 4.0 g of lettuce, 2.0 g of silica as dispersant sorbent, 0.1 g of activated carbon as clean up sorbent and acetonitrile as eluting solvent. The method was validated using lettuce samples fortified with pesticides at six different concentration levels (0.1 to 2.0 mg/kg). Average recoveries (7 replicates) ranged from 50 to 120%, with relative standard deviations between 0.6 and 8.0%. Detection and quantification limits for lettuce ranged from 0.01 to 0.02 mg/kg and 0.04 to 0.10 mg/kg, respectively.
authors.affiliation: Departamento de Química, Universidade Federal de Sergipe, São Cristóvão, Brazil.
authors.forename: Rogério Luiz
authors.initials: RL
authors.lastname: Da Silva
authors.forename: Claudia Pereira
authors.initials: CP
authors.lastname: Da Silva
authors.forename: Sandro
authors.initials: S
authors.lastname: Navickiene
mesh_terms: D000097:Acetonitriles / Q000737:chemistry; D001643:Bridged Bicyclo Compounds / Q000032:analysis; D002219:Carbamates / Q000032:analysis*; D004726:Endosulfan / Q000032:analysis; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006843:Hydrocarbons, Chlorinated / Q000032:analysis*; D018545:Lactuca / Q000737:chemistry*; D008294:Malathion / Q000032:analysis; D008743:Methyl Parathion / Q000032:analysis; D009943:Organophosphorus Compounds / Q000032:analysis*; D010573:Pesticide Residues / Q000032:analysis*; D011743:Pyrimidines / Q000032:analysis; D052616:Solid Phase Extraction / Q000379:methods; D012997:Solvents / Q000737:chemistry
chemical_list: D000097:Acetonitriles; D001643:Bridged Bicyclo Compounds; D002219:Carbamates; D006843:Hydrocarbons, Chlorinated; D009943:Organophosphorus Compounds; D010573:Pesticide Residues; D011743:Pyrimidines; D012997:Solvents; C011994:pirimicarb; D008743:Methyl Parathion; C035988:procymidone; D004726:Endosulfan; D008294:Malathion; C032159:acetonitrile