Multi-class method for determination of veterinary drug residues and other contaminants in infant formula by ultra performance liquid chromatography–tandem mass spectrometry

Multi-residue determination of 115 veterinary drugs and pharmaceutical residues in milk powder, butter, fish tissue and eggs using liquid chromatography–tandem mass spectrometry

“…These concentrations, although they are higher than LOQ, are very low and far below the MRL established for these benzimidazoles in milk (10μg kg −1 and 100 μg kg −1 ). Several quinolones were detected in milk (ciprofloxacin at7.3μg kg −1 and norfloxacin at 2.2μg kg −1 ) and fish tissue samples (flumequine at 4.6μg kg −1 and enrofloxacin at 4.8 μg kg −1 ).Thiabendazole was detected and quantified at 9.7 μg kg −1 in one butter sample and, finally, caffeine was present in 6 milk powder samples, at concentrations ranging from 2.4 to 32μg kg −1 .There was no compound detected and quantitated that would exceed the MRL established in Regulation37/2010/EC.The obtained results are inagreement with other studies[18, 21, 22,24,29].…”

“…The same applies for ionophorecoccidiostats (monensin, salinomycin and semduramycin) that also presentedlow recoveries in butter samples due to their hydrophobicity, which makes their separation from fatty samples nearly impossible [24].…”

“…Finally, another parameter that affects the chromatographic analysis and needs to be taken into consideration is the composition of the reconstitution solvent of the extract after the evaporation step. The high content of water (about 90%) in the final extract is preferred for the hydrophilic analytes while the high content of organic solvent (about 50%) is more suitable for the hydrophobic analytes [24]. In the present study, the reconstitution solvent consisted of methanol/aqueous solution of formic acid, 0.05% (25:75 v/v) and this choice was made after an extensive optimization performed for most of the analytes.…”

“…Low temperature clean up is a recently reported technique that amplifies the precipitation of proteins and fat from the sample [24,46]. In an effort to obtain even more clear extracts further defatting with hexane followed.…”

Identification in residue analysis based on liquid chromatography with tandem mass spectrometry: Experimental evidence to update performance criteria

“…MS) which is in agreement with reference data of the analyte and meets acceptable criteria for the purpose of the analysis. [27][28][29]. As regulators and laboratories strive to increase the scope of the methods to improve consumer safety, this multiclass-multi-analyte approach is expected to become more widely used in routine monitoring.…”