title: Direct extraction of tetracyclines from bovine milk using restricted access carbon nanotubes in a column switching liquid chromatography system.
abstract: This paper describes, for the first time, the use of restricted access carbon nanotubes (RACNTs) in the analysis of tetracyclines from milk samples, in a multidimensional liquid chromatographic system. Milk samples were initially acidified and centrifuged, and then the supernatant was directly analyzed in a column switching system in backflush configuration employing an extraction column of RACNTs. The sorbent was able to exclude all the remained proteins in less than 2.0min. The method was linear from 50 to 200μgL-1and the coefficients of determination (r2) were 0.997, 0.992, 0.994 and 0.998 for oxytetracycline (OXI), tetracycline (TC), chlortetracycline (CTC) and doxycycline (DOX), respectively. The analytical range included the maximum residue limits established by the regulatory agency.
authors.affiliation: Laboratory of Toxicant and Drug Analyses, Gabriel Monteiro da Silva St. 700, Federal University of Alfenas - Unifal-MG, 37130-000, Alfenas, MG, Brazil.
authors.forename: Henrique Dipe
authors.initials: HD
authors.lastname: de Faria
authors.affiliation: Laboratory of Toxicant and Drug Analyses, Gabriel Monteiro da Silva St. 700, Federal University of Alfenas - Unifal-MG, 37130-000, Alfenas, MG, Brazil.
authors.forename: Mariana Azevedo
authors.initials: MA
authors.lastname: Rosa
authors.affiliation: Laboratory of Toxicant and Drug Analyses, Gabriel Monteiro da Silva St. 700, Federal University of Alfenas - Unifal-MG, 37130-000, Alfenas, MG, Brazil.
authors.forename: Alberto Thalison
authors.initials: AT
authors.lastname: Silveira
authors.affiliation: Laboratory of Toxicant and Drug Analyses, Gabriel Monteiro da Silva St. 700, Federal University of Alfenas - Unifal-MG, 37130-000, Alfenas, MG, Brazil. Electronic address: eduardocfig@yahoo.com.br.
authors.forename: Eduardo Costa
authors.initials: EC
authors.lastname: Figueiredo
mesh_terms: D000818:Animals; D002853:Chromatography, Liquid; D008892:Milk / Q000737:chemistry; D037742:Nanotubes, Carbon / Q000737:chemistry*; D013754:Tetracyclines / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D037742:Nanotubes, Carbon; D013754:Tetracyclines
keywords: Carbon nanotubes; Chlortetracycline (PubChem CID: 54675777); Column switching; Doxycycline (PubChem CID: 54671203); Liquid chromatography; Milk; Oxytetracycline (PubChem CID: 54675779); Restricted access carbon nanotubes; Restricted access materials; Tetracycline (PubChem CID: 54675776); Tetracyclines