Raw, inhibitors free milk was spiked with penicillin G, ampicillin, cloxacillin, and ceftiofur at the levels 1 × MRL, 1.5 × MRL, and 2 × MRL, and oxytetracycline at the levels 100 ppb (MRL), 500 ppb and 700 ppb. The samples were stored at 4 ± 2 C and -18 ± 2 C and were tested every day and week, respectively. The analyses were performed using microbiological diffusion test Delvotest SP-NT and receptor assay CHARM ROSA MRL BL/TET for the detection of β-lactams and tetracyclines. In cooled samples antibiotics were detected up to 72 h. After this time, the samples were acidulated and not suitable for investigations. In frozen samples, depending on type and concentration of antibiotics, these substances were detected from one week (penicillin G - 4 ppb) to 35 weeks (ampicillin and ceftiofur).
If the inline PDF is not rendering correctly, you can download the PDF file here.
1. Berendsen B.J.A., Elbers I.J.W., Stolker A.A.M.: Determination of the stability of antibiotics in matrix and reference solutions using a straightforward procedure applying mass spectrometric detection. Food Addit Cont 2011, 28, 1637-1666.
2. Commission Regulation (EU) No 37/2010 of 22 December 2009 on pharmalogically active substances and their classification regarding maximum residue limits in foodstuffs of animal origin. OJ L 15, 20.1.2010, p. 1.
3. Freitas A., Barbosa J., Ramos F.: Determination of amoxicillin stability in chicken meat by liquid chromatography-tandem mass spectrometry. Food Anal Methods 2012, 5, 471-479.
4. Honikel K.O., Schmidt U., Woltersdorf W., Leistner L.: Effect of storage and processing on tetracycline residues in meat and bones. J Assoc Off Anal Chem 1978, 61, 1222-1227.
5. Khaskheli M., Malik R.S., Arain M.A., Soomro A.H., Arain H.H.: Detection of β-lactam antibiotic residues in market milk. Pakistan J Nutr 2008, 7, 682-685.
6. Nisha A.R.: Antibiotic residues-a global health hazard. Vet World 2008, 1, 375-377.
7. O’Brien J.J., Campbell N., Conaghan T.: Effect of cooling and cold storage on biologically active antibiotic residues in meat. J Hyg Comb 1981, 87, 511-523.
8. Okerman L., Van Hende J., De Zutter L.: Stability of frozen stock solutions of beta-lactam antibiotics, cephalosporins, tetracyclines and quinolones used in antibiotic residue screening and antibiotic susceptibility testing. Anal Chim Acta 2007, 586, 284-288.
9. Papapanagniotou E.P., Fletorius D.J., Psomas E.I.: Effect of various heat treatment and cold storage on sulphamethazine residues stability in incurred piglet muscle and raw milk samples. Anal Chim Acta 2005, 529, 305-309.
10. Pavlov A., Lashev L., Rusev V.: Studies on the residue levels of tobramycin in stored poultry products. Trakia J Sci 2005, 3, 20-22.
11. Podhorniak L.Y., Leake S., Schenk F.J.: Stability of tetracycline antibiotics in raw milk under laboratory storage conditions. J Food Protect 1999, 62, 547-548.
12. Riediker S., Rytz A., Stadler R.H.: Cold-temperature stability of five β-lactam antibiotics in bovine milk and milk extracts prepared for liquid chromatography-electroscopy ionization tandem mass spectrometry analysis. J Chromatogr A 2004, 1054, 359-363.
13. Schenk F.J., Friedman S.L.: The effect of storage at 4 C on the stability of ampicillin residues in raw milk. Food Addit Contam 2000, 17, 675-677.
14. Verdon E., Fuselier R., Hartaud-Pessel D., Couëdor P., Cadieu N., Laurentie M.: Stability of penicillin antibiotic in meat during storage. Ampicillin. J Chromatogr A 2000, 882, 135-143.