Validation of multi-residue method for quantification of antibiotics and nsaids in avian scavengers by using small amounts of plasma in HPLC-MS-TOF.

Abstract

Pharmaceuticals are still considered emerging pollutants a ecting both aquatic and terrestrial ecosystems. Scavenging bird species may be exposed to veterinary drugs when they feed on livestock carcasses provided at supplementary feeding stations, as these are often stocked with ailing and/or recently medicated animals. Because those animals may be a source of several di erent pharmaceutical compounds, analytical methods to evaluate residue levels and exposure potential should enable detection and quantification of asmanydi erent compounds as possible, preferably from small sample volumes. Four di erent extraction methods were tested to conduct HPLC-MS-TOF analysis of some of the most common veterinary drugs used in livestock in Spain. The method deemed most viable was a simple extraction, using methanol and 100 L of plasma, that allowed quantification of seven antibiotics (tetracycline, oxytetracycline, ciprofloxacin, enrofloxacin, nalidixic acid, trimethoprim, sulfadiazine) and five nonsteroidal anti-inflammatory drugs (NSAIDs) (meloxicam, flunixin, carprofen, tolfenamic acid, phenylbutazone). The method was then applied to analysis of 29 Eurasian gri on vulture (Gyps fulvus) nestling samples, wherein enrofloxacin and tolfenamic acid were most commonly detected (69% and 20%, respectively). To our knowledge, this is the first study including NSAIDs in the exposure assessment of di erent classes of veterinary pharmaceuticals in live avian scavengers.