title: Development and validation of an LC-APCI-MS-MS analytical method for the determination of streptomycin and dihydrostreptomycin residues in milk.
abstract: An analytical method for the quantification and identity confirmation of streptomycin and dihydrostreptomycin residues in pasteurized milk using liquid chromatography (LC)-atmospheric pressure chemical ionization (APCI)-tandem mass spectrometry (MS-MS) was developed and validated. Method validation was performed according to the recommendations of the international agencies European Community and IUPAC, and the following parameters were evaluated: analytical curve, linearity, sensitivity, precision (intra- and inter-day repeatability), accuracy, and the limit of detection (LOD) and limit of quantification (LOQ). Simple sample preparation was followed by the LC-APCI-MS-MS analysis. The method presented adequate linearity with correlation coefficients above 0.99 for both analytes in the dynamic range of 50-400 microg/kg, and average accuracies between 84-110%. The LOD and LOQ were, respectively, 25 microg/kg and 50 microg/kg for both analytes. Method selectivity was verified by the absence of interfering peaks in the retention regions of the analytes and the internal standard when a blank sample was tested. The results qualified the method for the quantification and confirmation of the analytes in milk at concentrations inferior to the established maximum residue limits (200 microg/kg).
authors.affiliation: School of Food Engineering, Department of Food Science, University of Campinas, P.O. Box 6121, 13084-971 Campinas, SP, Brazil. renata29269@hotmail.com
authors.forename: Renata Cabrera
authors.initials: RC
authors.lastname: de Oliveira
authors.forename: Jonas Augusto Rizzato
authors.initials: JA
authors.lastname: Paschoal
authors.forename: Marcela
authors.initials: M
authors.lastname: Sismotto
authors.forename: Flávia Pereira da Silva
authors.initials: FP
authors.lastname: Airoldi
authors.forename: Felix Guillermo Reyes
authors.initials: FG
authors.lastname: Reyes
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis; D002417:Cattle; D002853:Chromatography, Liquid / Q000379:methods*; D004096:Dihydrostreptomycin Sulfate / Q000032:analysis*; D004350:Drug Residues / Q000032:analysis*; D008892:Milk / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013307:Streptomycin / Q000032:analysis*; D053719:Tandem Mass Spectrometry / Q000379:methods
chemical_list: D000900:Anti-Bacterial Agents; D004096:Dihydrostreptomycin Sulfate; D013307:Streptomycin