Send to

Choose Destination
Food Addit Contam. 2003 Jun;20(6):528-34.

Residues of beta-lactam antibiotics in bovine milk: confirmatory analysis by liquid chromatography tandem mass spectrometry after microbial assay screening.

Author information

Dipartimento di Produzioni Animali, Biotecnologie Veterinarie, Qualità e Sicurezza degli Alimenti, Sezione Sicurezza degli Alimenti, Università degli Studi di Parma, Via del taglio 8 I-43100, Parma, Italy.


A procedure for the simultaneous determination of the residues of seven beta-lactam antibiotics (penicillin G, ampicillin, oxacillin, amoxicillin, dicloxacillin, cephalexin, cephapirin) in bovine raw milk using tandem liquid chromatography mass spectrometry (LC-MS/MS) is described. The antibiotics were extracted by an acetic acid solution after centrifugation and filtration. The beta-lactams were separated using reversed-phase liquid chromatography. A triple quadrupole mass spectrometer was used in positive-ion mode as a detector via a Turbo Ionspray interface for electrospray ionization (ESI). The limits of detection and quantitation of the method were below the legal tolerances, except for ampicillin. The method was used to confirm 53 samples found positive by a microbial method (Delvotest SP) at the Istituto Zooprofilattico Sperimentale per la Lombardia e l'Emilia Romagna of Brescia during 2001. Penicillin G was found in 26 samples at concentrations ranging from less than 4 to 6240+/-550 microg x l(-1). Amoxicillin was found in three samples at concentrations ranging from 8.5+/-0.1 to 53.7+/-2.3 microg x l(-1). Cephapirin was found in two samples at 5.7+/-0.1 and 6.4+/-0.3 microg x l(-1).

[Indexed for MEDLINE]

Supplemental Content

Loading ...
Support Center