Location: Contaminant Fate and Transport ResearchTitle: Development of an efficient extraction method for oxytetracycline in animal manure for high performance liquid chromatography analysis Author
Submitted to: Journal of Environmental Science and Health
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/16/2010
Publication Date: 8/27/2010
Citation: Yuan, S., Wang, Q., Yates, S.R., Petterson, N.G. 2010. Development of an efficient extraction method for oxytetracycline in animal manure for high performance liquid chromatography analysis. Journal of Environmental Science and Health. 45(7):612-620. Interpretive Summary: Veterinary antibiotics are widely administrated to animals in modern confined animal feeding operations to treat infectious disease, protect animal health, and improve feed efficiency. Research has found that veterinary antibiotics enter the environment and, through leaching and runoff, may contaminate water bodies. Tetracyclines are a major veterinary antibiotic family with activities against bacterial diseases. In order to study the environmental fate and transport of oxytetracycline related to animal feeding operations, efficient methods are needed to extract this compound from steer manure. This paper reports on an extraction method that has recoveries that ranged from about 85 to 105 % of the material applied to the sample. The high recovery rate indicates that the extraction method is efficient and should be a useful methodology for the research community. Furthermore, the result from this study provides important information that will help researchers, and regulators to study various factors affecting antibiotic fate in and around animal feed lots.
Technical Abstract: Oxytetracycline (2-(amino-hydroxy-methylidene)-4-dimethylamino-5,6,10,11,12a-pentahydroxy-6-methyl-4,4a,5,5a-tetrahydrotetracene- 1,3,12-trione) is a majormember of the tetracycline antibiotics family ofwhich are widely administered to animals in concentrated animal feeding operations for purposes of therapeutical treatment and health protection. With the disposal of animal manure as fertilizer into agricultural land, tetracyclines enter the environment. However, tetracyclines chelate with multivalent cations and proteins, resulting in low extraction efficiencies from animal manure for tetracycline residue analysis. In this study an efficient extraction method for oxytetracycline from steer manure using methanol/water solution amended with chelating organic acid was developed for the analysis of high performance liquid chromatography. The effect of species and amount of amendment acids, shaking time, methanol/water ratio, manure weight, and repeated times of extraction was investigated. It was optimized to amend 2.5 g citric acid and 1.1 g oxalic acid with 10.0 g manure sample in a 50-ml centrifuge tube and extract with 15 ml methanol/water (9:1 in volume) by vigorously shaking for 30 min in a reciprocating shaker. After centrifugation at 11,000 rpm, supernatant is collected. Sample was extracted for a total of 3 times. The developed extraction method was further applied to extract oxytetracycline from fresh and aged cow manure, swine and poultry manure, and soil. Satisfactory recoveries ranging from (84.1 ± 2.4) % to (102.0 ± 3.1)% were obtained, demonstrating that the optimized extraction method is robust for oxytetracycline from different manure sample matrixes.