Transfer And Cumulation Of Veterinary Tetracycline Antibiotics In Cycle Agriculture And Tecnology Of Interdiction

Antibiotics has been used in aquculture to treat specific diseases therapeutically and subtheraputically for increased feed efficiency or disease prevention for a long term,. Some antibiotics, however, are not absorbed very well by the animal and are passed in the urine or in manure. As manure is spread on fields as fertilizer, so are the antibiotics, which lead to the soil, especially agricultural soil has become a huge repository of veterinary antibiotics. That leading to concerns that these compounds may have a undesirable impact on human health and environment. Up to several hundreds milligram per kilogram of single antibiotic has been detected in agricultural soil, considering the collection characteristics of soil for various pollutants, the cumulative concentration of many antibiotics will be very alarming. Though antibiotics of veterinary origins have been widely detected in agricultural environment, there are little knowledge about the impact of these emerging environmental pollutants on the environment, especially the bio-cumulative characteristics of these antibiotics in crops and the impact on human health are poorly understood. It is necessary to conduct a further study on the transportation, degradation, bio-cumulating and the impact on the environment and human health of these emerging environmental pollutantsIn this article, four tetracycline antibiotics, the most extensively used antibiotics through the global, were selected as the study object. A sensitive analytical method was developed for determining selected antibiotics in plants, runoff water, soil and swine manure using high performance liquid chromatography tandem electrospray ionization-mass spectrome -try with multiple reactions monitoring (MRM) and high-performance liquid chromatogra -phy with ultra -violate detection. And the uptake of selected antibiotics by vegetables were studied. The tech -nology and measurement to prevent the antibiotics from uptaking by vegetables were investi -gated and the transfer, degradation and leaching of selected anti -biotics in the field after man -ure was fertilized to the agricultural soil were investigated too.On the whole, in this study we focused on:1. The methods for determination of selected antibiotics in the environment. A sensitive analytical method was developed for determining selected antibiotics (four compounds inclu -ding tetracycline, oxytetracycline, cholortetra -cycline and doxycline) in plants, water, soil and manure. Compounds in the water were enriched through solid phase extraction (SPE) with an Oasis HLB cartridge, for plant, soil and manure, compounds were extracted using oscillator and clean up by SPE. The extract -ed antibiotics were analyzed using high-performance liquid chromatography-electrospray ionization tandem mass spectrometry with multiple reaction monitoring (MRM). Good recov -eries rates and limits of quantification (LOQ) of target antibiotics in vegetables, water, soil and manure were obtained. The recoveries of four tetracyclins were between 64% and 92.7% with RSD<10.5% (n=5) in plant samples and between 68% and 93.4% with RSD<7.5% (n=5) in water samples.For oxytetracyline, tetracycline, chloro -tetracycline and doxytetracyline, the limit of quantification(LOQ) was 1,2,3,1μg/kg in radish and 0.025,0.013,0.062,0.015μg/L in water, respectively.2. The uptake of antibiotics by vegetables:The experiment results showed that the selected four antibiotics were uptook by Chinese white radish and pachoi. The concen -tration of antibiotics in plant tissue increased with increasing of antibiotics in manure amended soil and showed in significant positive correlation. When the antibiotics in soil were increased from 40 mg/m2 to 100 mg/m2 land, the concentration of four antibiotics were increased by 67% (tetracycline),105%(oxytetracycline), 71%(chlorotetracycline),83%(doxycline) in har- vested stems and leaves of pachoi and were increased by 58% (tetracycline),41% (oxytetracycline),88%(chlorotetracycline),24%(doxycline) in harvested radish tissues.The different plant shows different cumulative characteristic for antibiotics. The concen-tration of all four selected antibiotics in pachoi tissues were higher than that in radish tissues, the uptake of antibiotics by plants not only depends on the physical and chemical proerity but also on the plant species. The soil prosperity have an effect on the uptake of antibio -tics by plant. The antibiotics in sandy soil are more easily uptook by plant than red soil.3. The transfer and degradation of selected antibiotics in agricultural field:the organic fertilizer sources of tetracycline antibiotics can be degraded in in the sub -tropical environment, the half-lives of four tetracyclines in farmland were between 15.8 day and 20.6 days and show -ed easier to degrade under the natural and climate conditions and in the soil were investigated. The vertical migration of four selected anti -biotics have been observed in the soil of region where this experiment was conduct -ed. After fertilization 50 days, between 22 and 52μg/kg of tetracycline antibiotics were detected in subsurface (20-40 cm) soil. Antibiotics in agricultural soil can migrate with runoff and leachate. The peak concentration of four antibiotics in runoff were 0.2648μg/L (TC),0.3257μg/L (OTC),0.3708μg/L (CTC) and 0.2392μg/L (DOXY), and the peak concentration of four antibiotics in leachate were 0.1694μg/L (TC),0.2468μg/L (OTC),0.2302μg/L (CTC) and 0.2123μg/L (DOXY).4. Antibiotics transfer in cycle agricultural production blocking:The effects of aerobic composting and different conditioning materials on the degradation of antibiotics in man -ure were investigated. The results showed that aerobic composting can accelerate the de -gradation of antibiotics in manure. After 35 days composting, the removal efficiency for four antibiotics of different treatments followed the:the rice straw + manure> sawdust + manure> SSP + manure> pure pig manure composting. Mixed use of organic manure and superphosphate can significantly reduce the antibiotics transfer to the plants, when 2 kilo -grams manure mixed with 45 grams superphosphate were applied to soil, the residues of antibiotics in crops can be reduced by 25% minimumly and 61% maxi -mumly.For some crops, fertilizer before planting can reduce residues of antibiotics in crops.