Detection of ethinyl estradiol and resorcylic acid lactones in poultry meat according to the national residue plan

The aim of this study was the detection of ethinyl estradiol and resorcylic acid lactones (zeranol and taleranol) in poultry meat samples as unauthorized substances included in the Italian national residue plan. The samples were purified by a solid phase extraction using a C18 column combined with alumina, and the analytes were detected by two specific ELISA kits. As they were collected in the frame of official control activities, the method was also validated according to the Commission Decision 2002/657/EC requirements for screening methods with qualitative purpose. Specificity and detection capability were the performance criteria considered for the validation study, and the latter parameter showed a value of 0.5 μg/kg for both the investigated compounds. Such result was well comparable with the data reported by using chromatographic techniques as confirmation methods, and therefore the ELISA kits tested in this study could be used for the screening of large numbers of samples

Investigation of Nonionophoric Coccidiostat Residues in Feed as a Consequence of Carryover

Residues of nonionophoric coccidiostats at carryover concentrations in feedstuffs collected from feed mills or animal farms in central Italy were detected as part of the official controls carried out from 2011 through 2016. The 118 samples were collected on the production line or during feed distribution and storage to determine the sampling sites at major risk of cross-contamination. For determination of nonionophoric coccidiostats, a fast, easy, and cheap method was developed and validated. Feed samples were extracted with acetonitrile-methanol and directly injected for liquid chromatography with tandem mass spectrometry. A total of 24 samples (20.3%) were positive, but only 5 (4.2%) of these samples exceeded the maximum limit set by European legislation. Most of the positive samples were collected from a batch of feed produced immediately following processing of another batch to which the coccidiostat robenidine had been added

Development and Validation of a Method for the Determination of Quinolones in Muscle and Eggs by Liquid Chromatography-Tandem Mass Spectrometry

In this study, the development and validation of a multiresidue method for the detection of 11 quinolones (marbofloxacin, norfloxacin, ciprofloxacin, danofloxacin, lomefloxacin, enrofloxacin, sarafloxacin, difloxacin, oxolinic acid, nalidixic acid, flumequine) in muscle and eggs were reported. The method involved an extraction with a methanol/metaphosphoric acid mixture and a clean up by Oasis hydrophilic-lipophilic balance (HLB) cartridge. The validation was performed according to the Commission Decision 2002/657/EC. Linearity, specificity, decision limit (CCα), detection capability (CCβ), recovery, precision (repeatability and within-laboratory reproducibility), and ruggedness were determined. Depending on the analytes, CCα and CCβ ranged from 113 to 234 μg/kg and from 126 to 282 μg/kg in muscle samples, whereas in eggs, these parameters were between 5.6 and 7.4 μg/kg and between 6.1 and 9.8 μg/kg, respectively. In both the examined matrices, the recovery values were always higher than 90 % and precision, calculated as relative standard deviation, was equal to or lower than 16 % for repeatability and 23 % for within-laboratory reproducibility. The described method can be considered adequate for the simultaneous determination and quantification of quinolones in the tested food matrices

Determination of regulatory ionophore coccidiostat residues in feedstuffs at carry-over levels by liquid chromatography-mass spectrometry

<div><p>In this study samples of feedstuffs were collected from different feed mills and animal farms located in central Italy and analyzed for ionophore coccidiostat residues at carry-over levels by liquid chromatography-mass spectrometry. Since unavoidable cross-contamination of feedstuffs may occur during their production as well as distribution and storage, the collection of samples covered all these different stages. Residues of lasalocid, monensin, salinomycin and maduramicin were detected in 32.4% of samples, both at production and storage level. The maximum content for unavoidable carry-over set by Regulation (EU) No 574/2011 was exceeded in 11.3% of samples. The variability of the results highlighted the different approach of each investigated feed business operator to avoid any cross-contamination in non-target feed. The method developed in this study can be able to detect ionophore coccidiostats at low concentrations consequent to carry-over.</p></div

Validation data.

<p>Validation data.</p

Chromatogram of representative blank feed spiked with 1.25 mg kg^-1 of nigericin.

<p>For each analyte, the most intense product ion was selected.</p

Regulatory limits for ionophore coccidiostats in non-target feed following carry-over.

<p>Regulatory limits for ionophore coccidiostats in non-target feed following carry-over.</p

LC-MS/MS parameters for detection of ionophore coccidiostats in MRM mode.

<p>LC-MS/MS parameters for detection of ionophore coccidiostats in MRM mode.</p

Calibration curve points.

<p>Calibration curve points.</p