title: Simplified multiresidue method for determination of pesticide residues in lettuce by gas chromatography with nitrogen-phosphorus detection.
abstract: A rapid and simple method has been developed for simultaneous determination of different classes of pesticide in different varieties of lettuce (Lactuca sativum). Lettuce samples were extracted by homogenization with acetone and partitioned into ethyl acetate-cyclohexane. Subsequent sample clean-up was not needed. Pesticide residues were determined by capillary gas chromatography with nitrogen-phosphorus detection (NPD). Confirmatory analysis of the pesticides was performed by capillary gas chromatography coupled with mass spectrometry in selected-ion-monitoring (SIM) mode. Recovery at two levels of fortification (ca. 0.05 and 0.20 mg kg(-1)) ranged from 63.9 to 118.6%, and relative standard deviations were below 9.5%. The proposed method was used to determine pesticide levels in different types of lettuce grown in soil from experimental fields.
authors: Instituto Murciano de Investigación y Desarrollo Agrario y Alimentario, C/ Mayor s/n, La Alberca, 30150 Murcia, Spain. jose.fenoll@carm.es
authors: José
authors: J
authors: Fenoll
authors: Pilar
authors: P
authors: Hellín
authors: Josefa
authors: J
authors: López
authors: Alberto
authors: A
authors: González
authors: Pilar
authors: P
authors: Flores
mesh_terms: D002849:Chromatography, Gas / Q000379:methods*; D018545:Lactuca / Q000737:chemistry*; D013058:Mass Spectrometry; D009584:Nitrogen; D010573:Pesticide Residues / Q000032:analysis*; D010758:Phosphorus; D012015:Reference Standards; D012680:Sensitivity and Specificity
chemical_list: D010573:Pesticide Residues; D010758:Phosphorus; D009584:Nitrogen