• Detection of banned nitrofuran metabolites in animal plasma samples using UHPLC–MS/MS

      Radovnikovic, Anita; Moloney, Mary; Byrne, Patrick; Danaher, Martin (Elsevier, 2010-12-07)
      The use of nitrofurans as veterinary drugs in food-producing animals has been banned in the EU since the 1990s. Monitoring programs in the EU are based on the detection of protein-bound metabolites after slaughter. An UHPLC–MS/MS method was developed and validated for pre slaughter determination of four nitrofuran metabolites (AHD, AOZ, SEM, AMOZ) in animal plasma (bovine, ovine, equine and porcine). This method is proposed as an alternative method for on-farm surveillance. Plasma samples were derivatised with 2-nitrobenzaldehyde and subsequently extracted with organic solvent. Extracts were concentrated and then analysed by UHPLC–MS/MS. The method was validated according to Commission Decision 2002/657/EC. Inter-species recovery for AHD, AOZ, SEM and AMOZ was 72, 74, 57 and 71%, respectively. Decision limits (CC ) were calculated from within laboratory reproducibility experiments to be 0.070, 0.059, 0.071 and 0.054 gkg−1, respectively. In addition, the assay was applied to incurred plasma samples taken from pigs treated with furazolidone.
    • Residue analyses and exposure assessment of the Irish population to nitrofuran metabolites from different food commodities in 2009–2010

      Radovnikovic, Anita; Conroy, Emma-Rose; Gibney, Mike; O'Mahony, John; Danaher, Martin; Department of Agriculture, Food and the Marine, Ireland; Health Research Board; 07FHRIAFRC5 (Taylor & Francis, 16/09/2013)
      An exposure assessment to nitrofuran residues was performed for three human populations (adults, teenagers and children), based on residue analyses of foods of animal origin (liver, honey, eggs and aquaculture) covering the 2-year period 2009– 2010. The occurrence of nitrofuran metabolites in food on the Irish market was determined for the selected period using the data from Ireland’s National Food Residue Database (NFRD) and from results obtained from the analysis of retail samples (aquaculture and honey). Laboratory analyses of residues were performed by methods validated in accordance with Commission Decision 2002/657/EC regarding performance of the analytical method and interpretation of results. Semicarbazide (SEM) was the contaminant most frequently identified and its content ranged from 0.09 to 1.27 μg kg−1. SEM is currently used as a marker of nitrofuran abuse, but it may also occur from other sources. The presence of nitrofuran metabolite 3-amino-2-oxazolidinone (AOZ) was detected in two aquaculture samples (prawns) at 1.63 and 1.14 μg kg−1, but such a low number of positive cases did not present sufficient data for a full AOZ exposure assessment. Therefore, the evaluation of exposure was focused on SEM-containing food groups only. Exposure assessments were completed using a probabilistic approach that generated 10 iterations. The results of both the upper- and lower-bound exposure assessments demonstrate that SEM exposure for Irish adults, teenagers and children from selected food commodities are well below EFSA-estimated safe levels.