Evaluation of some screening tests for detection of β-lactams residues in milk production chain

Abstract

Despite of useful information on important factors of screening tests for the detection of drug residues in milk, the choice of a suitable test is still difficult. The aim of this study was to evaluate three different tests, including Copan, maximum residue limit (MRL) β- lactam and lactic coagulation test for routine screening of milk containing β-lactam antibiotics. Blank milk samples were added with different concentrations of three β- lactams, including penicillin, amoxicillin, ampicillin, and examined then by all three tests. Both Copan milk and MRL β-lactam tests were easy to use and sensitive to mentioned β- lactams at or below the MRLs established by European Union, but lactic coagulation test was not able to detect them at or even exceeding the safe level of MRLs. Copan test was also easier to interpret and less expensive while the results of MRL β-lactam were obtained in a short time. Depend on purpose, both Copan and MRL β-lactam tests can be applied as a screening test for the detection of β-lactams in raw milk.