Characterization of Ionophores in Poultry Litter and Litter Amended Soils Using Liquid Chromatograph Tandem Mass Sepctrometer.

Ionophores have been used as antimicrobials and anticoccidants at sub-therapeutic levels for many decades in poultry feed. They exhibit the highest toxicity among antimicrobials and may be introduced into the environment when poultry litter containing the residues are land applied. Recently, there has been an increasing concern about their persistence and potential impacts in the environment, including continued toxicity in soil amended with poultry manure. To answer these questions, it is important to characterize ionophores in the environment and examine their persistence in agricultural systems. Thus this project will deal with multi-scale investigation of the presence and magnitude of ionophores in poultry litter and litter-amended soil to determine if ionophores are an emerging soil contaminant. We will present optimization results for a highly sensitive method, using liquid chromatograph tandem mass spectrometer (LC-MS/MS), for quantification of ionophores in litters and litter amended soils.