Determination of White Phosphorus Residues in Ducks: An Atomic Emission Detection/Compound-Independent Calibration-Based Method of Generating Residue Data for Risk Assessment and Environmental Monitoring

Abstract

Analysis of phosphorus concentrations in the gizzards of ducks harvested from munitions sites is necessary to ascertain if acute phosphorus toxicity was the cause of death and to estimate potential secondary hazards to predators and scavengers, such as eagles that readily consume the dead ducks. Gas chromatography/atomic emission detection analysis permitted compound-independent quantification of white phosphorus standards following analysis of the stable phosphorus-containing compound triethyl phosphate. The white phosphorus standards were then used to quantify white phosphorus residues in duck gizzard extracts by gas chromatography/flame photometric detection analysis. For gizzards containing less than 0.01 μg of phosphorus, quantification was based on a three-point calibration curve. For gizzards containing 0.01 μg or more of white phosphorus, single-point calibration was used. Mean recoveries for phosphorus-fortified (0.03−3000 μg) gizzards ranged from 73 to 91%. The method limit of detection was 0.013 μg of phosphorus. This method was successfully applied to the quantification of white phosphorus in ducks collected from Eagle River Flats, AK. Potential applications to risk assessment and environmental monitoring are also discussed.