title: The occurrence of semicarbazide in the meat and shell of Bangladeshi fresh-water shrimp.
abstract: There is evidence that semicarbazide (SEM), a marker for the banned nitrofuran nitrofurazone, can arise from other, unrelated sources. Recently, Belgium rejected 54 consignments of Bangladeshi freshwater shrimp (Macrobrachium rosenbergii), following a laboratory decision to test meat and exoskeleton combined. To study the possible natural occurrence of SEM in wild shrimp, samples were collected and analysed from 29 sites across Bangladesh. SEM (<1.0 μg/kg) was detected in ∼65% of meat samples. However, SEM concentrations were approximately 100 times higher in the exoskeleton, and were unrelated to sampling location, strongly suggesting natural occurrence. In meat, most SEM was surface-associated. When the shrimp was shelled, some of the epidermal layer (which synthesises new exoskeleton) remained with the shell and some remained with the meat--leading to differing levels of natural SEM on the shrimp surface. This has implications for the use of SEM and the analytical strategy used to control nitrofuran use.
authors.affiliation: Chemical Surveillance Branch, Veterinary Sciences Division, Agri-Food & Biosciences Institute, Stoney Road, Stormont, Belfast BT4 3SD, Northern Ireland, UK. Robert.mccracken@afbini.gov.uk
authors.forename: Robert
authors.initials: R
authors.lastname: McCracken
authors.forename: Bob
authors.initials: B
authors.lastname: Hanna
authors.forename: David
authors.initials: D
authors.lastname: Ennis
authors.forename: Lynne
authors.initials: L
authors.lastname: Cantley
authors.forename: Dermot
authors.initials: D
authors.lastname: Faulkner
authors.forename: D Glenn
authors.initials: DG
authors.lastname: Kennedy
mesh_terms: D000818:Animals; D001459:Bangladesh; D005506:Food Contamination / Q000032:analysis; D008460:Meat / Q000032:analysis*; D033541:Palaemonidae / Q000737:chemistry*; D012663:Semicarbazides / Q000032:analysis*; D012758:Shellfish / Q000032:analysis*
chemical_list: D012663:Semicarbazides; C010059:carbamylhydrazine