title: Dispersive solid-phase extraction followed by liquid chromatography-tandem mass spectrometry for the multi-residue analysis of pesticides in raw bovine milk.
abstract: A fast multi-residue method based on dispersive solid-phase extraction (DSPE) followed by liquid chromatography-tandem mass spectrometry was developed for the simultaneous determination of 44 pesticides in raw bovine milk. Raw bovine milk samples did not percolate through SPE cartridges usually applied for pesticide extraction from homogenized pasteurized milk samples. Therefore, a DSPE technique was implemented and validated for the first time in this work. Graphitized non-porous carbon and C18 modified silica materials were tested both in combination with magnesium sulfate and bonded silica with ethylenediamine-N-propyl phase. The efficiency of the DSPE process was studied at several concentration levels obtaining the higher recoveries with C18 material. The method performance was also assessed and the limits of quantification reached the ng g(-1) level, complying with the most recent maximum residue levels. The DSPE method was also shown to be suited to both the fatty and skimmed fractions issued from raw milk. Finally, the extraction method was successfully applied to the analysis of raw milk samples collected in 23 farms of dairy cattle from NW Spain (Galicia).
authors.affiliation: INGACAL (Galician Institute for Food Quality)-CIAM (Agrarian and Agronomic Research Centre), Laboratory of Food/Feed Safety and Organic Contaminants, Apartado 10, E-15080 A Coruña, Spain. thierry.dagnac@xunta.es
authors.forename: Thierry
authors.initials: T
authors.lastname: Dagnac
authors.forename: Maria
authors.initials: M
authors.lastname: Garcia-Chao
authors.forename: Paula
authors.initials: P
authors.lastname: Pulleiro
authors.forename: Carmen
authors.initials: C
authors.lastname: Garcia-Jares
authors.forename: Maria
authors.initials: M
authors.lastname: Llompart
mesh_terms: D000818:Animals; D002417:Cattle; D005506:Food Contamination; D008892:Milk / Q000737:chemistry*; D010573:Pesticide Residues / Q000737:chemistry*; D012680:Sensitivity and Specificity; D052616:Solid Phase Extraction / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D010573:Pesticide Residues