title: Determination of avoparcin in animal tissues and milk using LC-ESI-MS/MS and tandem-SPE.
abstract: A highly sensitive and selective method using LC-ESI-MS/MS and tandem-SPE was developed to detect trace amounts of avoparcin (AV) antibiotics in animal tissues and milk. Data acquisition using MS/MS was achieved by applying multiple reaction monitoring of the product ions of [M + 3H](3+) and the major product ions of AV-alpha and -beta at m/z 637 --> 86/113/130 and m/z 649 --> 86/113/130 in ESI(+) mode. The calculated instrumental LODs were 3 ng/mL. The sample preparation was described that the extraction using 5% TFA and the tandem-SPE with an ion-exchange (SAX) and InertSep C18-A cartridge clean-up enable us to determine AV in samples. Ion suppression was decreased by concentration rates of each sample solution. These SPE concentration levels could be used to detect quantities of 5 ppb (milk), 10 ppb (beef), and 25 ppb (chicken muscle and liver). The matrix matching calibration graphs obtained for both AV-alpha (r >0.996) and -beta (r >0.998) from animal tissues and milk were linear over the calibration ranges. AV recovery from samples was higher than 73.3% and the RSD was less than 12.0% (n = 5).
authors.affiliation: Department of Physical and Analytical Chemistry, School of Pharmacy, Kinjo Gakuin University, Moriyama-ku, Nagoya, Japan. kinoue@kinjo-u.ac.jp
authors.forename: Koichi
authors.initials: K
authors.lastname: Inoue
authors.forename: Yasuomi
authors.initials: Y
authors.lastname: Mizuno
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Yoshimi
authors.forename: Mari
authors.initials: M
authors.lastname: Nunome
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Hino
authors.forename: Kaname
authors.initials: K
authors.lastname: Tsutsumiuchi
authors.forename: Hisao
authors.initials: H
authors.lastname: Oka
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis*; D002853:Chromatography, Liquid / Q000379:methods*; D006020:Glycopeptides / Q000032:analysis*; D008892:Milk / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D000900:Anti-Bacterial Agents; D006020:Glycopeptides; C016249:avoparcin