title: An improved dispersive solid-phase extraction clean-up method for the gas chromatography-negative chemical ionisation tandem mass spectrometric determination of multiclass pesticide residues in edible oils.
abstract: An improved sample preparation using dispersive solid-phase extraction clean-up was proposed for the trace level determination of 35 multiclass pesticide residues (organochlorine, organophosphorus and synthetic pyrethroids) in edible oils. Quantification of the analytes was carried out by gas chromatography-mass spectrometry in negative chemical ionisation mode (GC-NCI-MS/MS). The limit of detection and limit of quantification of residues were in the range of 0.01-1ng/g and 0.05-2ng/g, respectively. The analytes showed recoveries between 62% and 110%, and the matrix effect was observed to be less than 25% for most of the pesticides. Crude edible oil samples showed endosulfan isomers, p,p'-DDD, α-cypermethrin, chlorpyrifos, and diazinon residues in the range of 0.56-2.14ng/g. However, no pesticide residues in the detection range of the method were observed in refined oils.
authors.affiliation: National Centre for Mass Spectrometry, Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500007, Andhra Pradesh, India.
authors.forename: Pragney
authors.initials: P
authors.lastname: Deme
authors.forename: Tirupathi
authors.initials: T
authors.lastname: Azmeera
authors.forename: B L A
authors.initials: BL
authors.lastname: Prabhavathi Devi
authors.forename: Padmaja R
authors.initials: PR
authors.lastname: Jonnalagadda
authors.forename: R B N
authors.initials: RB
authors.lastname: Prasad
authors.forename: U V R
authors.initials: UV
authors.lastname: Vijaya Sarathi
mesh_terms: D005506:Food Contamination / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006843:Hydrocarbons, Chlorinated / Q000032:analysis / Q000302:isolation & purification; D009943:Organophosphorus Compounds / Q000032:analysis / Q000302:isolation & purification; D010573:Pesticide Residues / Q000032:analysis* / Q000302:isolation & purification*; D010938:Plant Oils / Q000032:analysis*; D052616:Solid Phase Extraction / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods
chemical_list: D006843:Hydrocarbons, Chlorinated; D009943:Organophosphorus Compounds; D010573:Pesticide Residues; D010938:Plant Oils
keywords: Dispersive solid-phase extraction; Edible oils; Gas chromatography; Negative chemical ionisation; Pesticides; Tandem mass spectrometry