‘Hot spots’ of veterinary residues found in corned beef case
The Official Analyst certified against the consignment of 54,000 cans (340g each) of Brazilian corned beef sampled at import for excess albendazole.
A laboratory acting for the importer reported data below the maximum residue limit (MRL), including a finding of the parent drug which is not included in the residue definition.
This is due to albendazole being extensively metabolized and metabolites are responsible for the activity of the medicine.
A technical appeal to the Government Chemist was made against the findings of the official analyst.
Hot spots present sampling issue?
The Government Chemist said results of the referee analysis overlapped with official findings and the consignment was rejected.
The analysis did not reveal presence of the parent drug but identified hot spots of albendazole marker residues pointing to issues with how samples are taken from consignments.
“The Government Chemist referee analysis upheld the finding of albendazole (as its sulphoxide) in excess of the permitted MRL in the consignment which was subsequently re-dispatched from the UK.
“The law, including case law, on the matter is reviewed showing that a finding of excess veterinary residue in some parts of a consignment means that the whole consignment can be taken to be unsafe and must be re-dispatched or destroyed.”
Analysis was done on two portions of the homogenised corned beef analysed by the labs previously involved, two unopened cans from the original sampling exercise and four randomly chosen from the second sampling exercise (two from each production date).
It consisted of acetonitrile extraction, liquid/liquid partitioning (acetonitrile/hexane) and solid phase extraction clean-up followed by liquid chromatography separation and tandem mass spectrometry detection and quantification (LC-MS/MS).
Isotopically labelled albendazole D3 and albendazole sulphoxide D3 were used as internal standards.
Of the 134 RASFF notifications for veterinary residues from January 2014 to June 2015, six were for albendazole residues – five for corned beef and one for frozen minced beef from Brazil.
Limits and analysis findings
Albendazole is one of the benzimidazole anthelmintics and is used in ruminants with a MRL in muscle, fat and other tissue.
Limits are set for residues in meat to 100 micrograms per kilogram (μg kg−1) as the sum of albendazole sulphoxide, albendazole sulphone, and albendazole 2-amino sulphone, expressed as albendazole.
The official lab reported 245 ± 65 μg kg−1 albendazole sulphoxide expressed as albendazole (no albendazole, albendazole sulphone, or albendazole 2-amino sulphone was detected).
A lab for the consignment owner reported an albendazole concentration of 80 μg kg−1 and albendazole sulphoxide 82 μg kg−1, equivalent to 77 μg kg−1 as the residue definition, as the albendazole concentration is not taken into account.
“One of the laboratories involved in the case reported finding the parent compound, albendazole, which is not included in the residue definition. We recommend that the residue definition should be reconsidered to include albendazole as well as its metabolites.
“Given the presence of hot spots of residues reported herein we recommend further research on sampling leading to practical guidance for sampling officers.”
Source: Food Additives & Contaminants: Part A
DOI: 10.1080/19440049.2016.1243807
“Resolution of a disputed albendazole result in the UK Official Control System - time for more guidance?”
Authors: Michael Walker, Kirstin Gray, Christopher Hopley, Christopher Mussell, Louise Clifford, Jayanie Meinerikandathevan, Leonardo Firpo, Joanna Topping and Daniel Santacruz
