1,720,996 research outputs found
Residues of ß-lactam antibiotics in bovine milk: confirmatory analysis by liquid chromatography tandem mass spectrometry after microbial assay screening
No full textA procedure for the simultaneous determination of the
residues of seven -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 -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
53samples 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 6240550g l1. Amoxicillin was found in three
samples at concentrations ranging from 8.50.1 to
53.72.3g l1. Cephapirin was found in two samples
at 5.70.1 and 6.40.3 g l1
Prevalence of molecules of b-lactam antibiotics in bovine milk in Lombardia and Emilia Romagna (Italy)
No full textGli autori riportano i risultati di una indagine preliminare sui livelli
di contaminazione di latte e carne prodotti con il sistema biologico o con i metodi tradizionali
da parte di pesticidi organoclorurati, policlorobifenili, piombo, cadmio e
micotossine. I residui di pesticidi e policlorobifenili sia nel latte che nella carne biologici
o convenzionali sono inferiori a limiti di legge e solo poche molecole sono
state osservate in un numero limitato di campioni. I residui di cadmio e piombo sono
pure molto bassi e non presentano differenze tra prodotti biologici e tradizionali. Il
contenuto di aflatossina M1 nel latte biologico è significativamente maggiore di quello
riscontrato nel latte convenzionale. Un quarto circa dei campioni (29 di tipo biologico
e 7 di tipo convenzionale) supera il limite di 50 ppt previsto per il latte vaccino
dal Regolamento CE 466/2001. La contaminazione da aflatossina M1 nel latte
sembra essere un problema di azienda
Residues of b-lactam antibiotics in bovine milk: HPLC-MS/MS confirmatory analysis after microbial assay screening
No full textThe analysis to detect antimicrobial residues in milk are usually performed in two steps: first, a microbiological method, based on the inibition of microbial growth, is used as a screening tool.
Second the samples found positive are confirmed by a chernical method. A confirmatory method has to be able to detect which molecule is present in the sample and to quantitate it. HPLC-UV is
the technique usually adopted as a confirmatory method. The use of this technique has some limitations. We developed a very fast chernical method based on HPLC-MS/MS. This method is able to
process a great number of samples per day, giving an error-proof confirmation and with a very high sensitivity. The method has been validated and tested on 27 bovine milk samples found
positive by a microbioiogical method at the IZSLER of Brescia
Prevalence of molecules of ß-lactam antibiotics in bovine milk in Lombardia and Emilia Romagna
No full text
- …
