title: High-performance liquid chromatography-based determination of nicarbazin excretion in waterfowl.
abstract: A method for the high-performance liquid chromatography (HPLC) determination of nicarbazin uptake and excretion in ducks is presented. The method uses few clean-up steps and provides a rapid assessment of nicarbazin excretion by measuring the analyte 4,4'-dinitrocarbanalide (DNC). During method development the effect of extraction volume, number of extractions, mobile phase composition, column temperature, and injection volume were varied to optimize sensitivity and achieve as short a run time as possible. For our purposes, a 2 x 5.0 ml 1:1 dimethyl formamide (DMF):acetonitrile (ACN) extraction injected (40 ml) into an HPLC system equipped with a Keystone octadecylsilyl (ODS) C18 column and a UV variable wavelength detector (lambda=347 nm) with a mobile phase of 60:40 (v/v) ACN-H2O, at a flow-rate of 1.0 ml/min at a column temperature of 35 degrees C provided adequate resolution and an acceptable total run time. Studies conducted during method development for inter-day recovery efficiencies for 0.46, 1.8 and 88.5 microg fortified samples (n=3) had mean recoveries of 91, 94 and 97% and intra-day (n=3) recoveries at the same fortification levels of 103, 94, and 92%. The method has been used successfully in excretion studies of nicarbazin in ducks.
authors.affiliation: National Wildlife Research Center, USDA/APHIS, 4101 La Porte Avenue, Fort Collins, CO 99801 USA.
authors.forename: Randal S
authors.initials: RS
authors.lastname: Stahl
authors.forename: John J
authors.initials: JJ
authors.lastname: Johnston
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003049:Coccidiostats / Q000032:analysis*; D004372:Ducks; D009528:Nicarbazin / Q000032:analysis*; D015203:Reproducibility of Results
chemical_list: D003049:Coccidiostats; D009528:Nicarbazin