title: A liquid-liquid extraction procedure followed by a low temperature purification step for the analysis of macrocyclic lactones in milk by liquid chromatography-tandem mass spectrometry and fluorescence detection.
abstract: In this work a method is proposed and demonstrated for the analysis of the macrocyclic lactones abamectin, doramectin, eprinomectin, ivermectin and moxidectin in bovine milk by liquid chromatography coupled to mass spectrometry (LC-MS/MS) and liquid chromatography with fluorescence detection (LC-FL). The method is based on liquid-liquid extraction followed by a low temperature purification (LLE-LTP) step. Moreover, the proposed method was validated according to the Commission Decision 2002/657/EC, using LC-MS/MS and LC-FL for confirmatory and quantitative analysis, respectively. For LC-MS/MS the recovery rates observed ranged from 101.2 to 141.6% with coefficient of variation from 2.6 to 19.8%. For LC-FL the recovery rates observed ranged from 100.2 to 105% and coefficient of variations from 2.9 to 8.8%. Matrix effects were negligible due to the low temperature purification step. The quantification limits were far below the maximum limits established by regulations of all countries consulted. The proposed method proved to be simple, easy, and adequate for high-throughput analysis of a large number of samples per day at low cost.
authors.affiliation: Programa de Pós-Graduação em Biologia Celular e Molecular, Centro de Biotecnologia do Estado do Rio Grande do Sul, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil. grubensam@yahoo.com
authors.forename: Gabriel
authors.initials: G
authors.lastname: Rübensam
authors.forename: Fabiano
authors.initials: F
authors.lastname: Barreto
authors.forename: Rodrigo Barcellos
authors.initials: RB
authors.lastname: Hoff
authors.forename: Tarso Ledur
authors.initials: TL
authors.lastname: Kist
authors.forename: Tânia Mara
authors.initials: TM
authors.lastname: Pizzolato
mesh_terms: D000818:Animals; D002417:Cattle; D002853:Chromatography, Liquid / Q000191:economics / Q000379:methods; D005453:Fluorescence; D007783:Lactones / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D059625:Liquid-Liquid Extraction / Q000191:economics / Q000379:methods*; D047028:Macrocyclic Compounds / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D008892:Milk / Q000737:chemistry*; D012680:Sensitivity and Specificity; D053719:Tandem Mass Spectrometry / Q000191:economics / Q000379:methods*
chemical_list: D007783:Lactones; D047028:Macrocyclic Compounds