title: Analysis by LC/ESI-MS of iophenoxic acid derivatives and evaluation as markers of oral baits to deliver pharmaceuticals to wildlife.
abstract: Iophenoxic acid and its derivatives (methyl, ethyl, and propyl) are organic chemicals used as markers in baiting campaigns to deliver vaccines, pharmaceuticals, contraceptives or poisons to wildlife. In this study we develop a method of detection of IPA derivatives by LC/ESI-MS (using butyl-IPA as internal standard) obtaining a limit of detection and quantification in wild boar (Sus scrofa) serum of 0.037 microg/ml and 0.123 microg/ml, respectively. The average recovery of IPA derivatives was 88% at levels >0.2 microg/ml, with coefficients of variation <15%. Wild boars in captivity were orally treated with 5 mg/kg b.w. (three adults) or 15 mg/kg b.w (two piglets and three adults) of methyl-, ethyl- and propyl-IPA and the serum levels of these were monitored during 18 months after dosing. Ethyl- and propyl-IPA were detected up to 18 months after a single oral dose in wild boar, especially at 15 mg/kg. Methyl-IPA was detected until 9 months after dosing. Half-lives of methyl-, ethyl- and propyl-IPA were (mean+/-SD) 41+/-5, 183+/-85 and 165+/-45 days, respectively. One control piglet not exposed to IPA, but housed in the same facility than treated animals showed detectable IPA levels in serum. Piglets born from mothers exposed to marked baits also showed detectable IPA levels in serum. The high persistence of Et- and Pr-IPA must be considered in the field trials, because the presence of the product at low levels in one animal may not reflect a real ingestion of the marked bait.
authors.affiliation: Instituto de Investigación en Recursos Cinegéticos, IREC (CSIC-UCLM-JCCM), Ronda de Toledo s/n, 13071 Ciudad Real, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Ballesteros
authors.forename: Pablo R
authors.initials: PR
authors.lastname: Camarero
authors.forename: Carles
authors.initials: C
authors.lastname: Cristòfol
authors.forename: Joaquín
authors.initials: J
authors.lastname: Vicente
authors.forename: Christian
authors.initials: C
authors.lastname: Gortazar
authors.forename: José
authors.initials: J
authors.lastname: de la Fuente
authors.forename: Rafael
authors.initials: R
authors.lastname: Mateo
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000835:Animals, Wild / Q000097:blood; D015415:Biomarkers / Q000032:analysis; D016503:Drug Delivery Systems; D005260:Female; D007480:Iopanoic Acid / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000032:analysis; D008297:Male; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D034421:Sus scrofa / Q000097:blood*; D019155:Veterinary Drugs / Q000008:administration & dosage / Q000032:analysis*
chemical_list: D015415:Biomarkers; D019155:Veterinary Drugs; C008160:iophenoxic acid; D007480:Iopanoic Acid