Sequestration of Manure-Applied Sulfadiazine Residues in Soils
Sequestration of Manure-Applied Sulfadiazine Residues in Soils
复制标题
DOI：
10.1021/es8026538
复制
发表时间：
2009-03-15
影响因子：
11.4
通讯作者：
Amelung, W.
中科院分区：
文献类型：
--
作者：
Foerster, M.;Laabs, V.;Amelung, W.
这是不是总的，但（生物）可及浓度的兽药，决定了它们在环境中的毒性，我们阐明了（生物）可及性的变化，粪肥应用磺胺嘧啶（SDZ）在土壤中的接触时间增加。用IT标记的SDZ对育肥猪进行药物处理，并将受污染的粪便（新鲜和老化）修改为2种土壤类型（Cambisol，Luvisol），并在10 ℃下在黑暗中孵育218天。通过用0.01 M CaCl（2）（CaCl（2）级分）、甲醇（MeOH级分）和最后乙腈/水（残余级分，在150 ℃下微波提取）的顺序提取来接近不同生物可利用性的抗生素残留物。在每个馏分中，对总放射性、SDZ及其主要代谢产物进行定量。结果表明，在施用新鲜肥料后的前2-4周内，SDZ和较小程度的4-羟基磺胺嘧啶（4-OH-SDZ）都迅速从N-乙酰磺胺嘧啶（N-ac-SDZ）重新形成，即，N-乙酰化代谢物在土壤中不会螯合到显著的程度。然而，水和甲醇提取的SDZ和4-OH-SDZ也迅速消散（DT（50）6.0-32天）的新鲜粪便处理与两种土壤类型相似的速率常数。然而，在残余馏分中，这两种化合物的浓度随时间增加。我们得出结论，残留部分包括SDZ及其羟基化代谢产物的螯合池。在那里，它们被捕获，并可能在土壤中持续数年。因此，将残留部分纳入归趋研究中，可得出SDZ的消散半衰期，超过先前报告的磺胺类药物的消散半衰期约100倍。
It is not the total but the (bio)accessible concentration of veterinary medicines that determines their toxicity in the environment We elucidate the changes in (bio)accessibility of manure-applied sulfadiazine (SDZ) with increasing contact time in soil. Fattening pigs were medicated with IT-labeled SDZ, and the contaminated manure (fresh and aged) was amended to 2 soil types (Cambisol, Luvisol) and incubated for 218 days at 10 degrees C in the dark. Antibiotic residues of different bioaccessibility were approached by sequential extractions with 0.01 M CaCl(2) (CaCl(2) fraction), methanol (MeOH fraction) and finally acetonitrile/water (residual fraction, microwave extraction at 150 degrees C). In each fraction, total radioactivity, SDZ, and its major metabolites were quantified. The results showed that both SDZ and,to a lesser extent 4-hydroxysulfadiazine (4-OH-SDZ) were rapidly reformed from N-acetylsulfadiazine(N-ac-SDZ) during the first 2-4 weeks after fresh manure application, i.e., the N-acetylated metabolite does not sequester in soil to a significant extent. Yet, the water and methanol extractable SDZ and 4-OH-SDZ also dissipated rapidly (DT(50) 6.0-32 days) for the fresh manure treatment with similar rate constants for both soil types. In the residual fractions, however, the concentrations of both compounds increased with time. We conclude that the residual fraction comprises the sequestered pool of SDZ and its hydroxylated metabolite. There they are entrapped and may persist in soil for several years. Including the residual fraction into fate studies thus yields dissipation half-lives of SDZ which exceed those previously reported for sulfonamides by a factor of about 100.