Adsorption of sulfonamide antimicrobial agents to clay minerals
Adsorption of sulfonamide antimicrobial agents to clay minerals
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DOI：
10.1021/es050644c
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发表时间：
2005-12-15
影响因子：
11.4
通讯作者：
Pedersen, JA
中科院分区：
文献类型：
--
作者：
Gao, JA;Pedersen, JA
研究了三种磺胺类抗菌剂在粘土矿物上的吸附随pH值、离子强度和可交换阳离子类型的变化规律。磺胺抗菌吸附表现出明显的pH值依赖性与山梨酸盐形态和粘土性质一致。磺胺类抗菌剂没有插入蒙脱石，表面电荷密度影响吸附确定吸附域的大小。吸附边缘数据最适合的模型，包括条款的阳离子和不带电的物种。不带电的磺胺二甲嘧啶吸附蒙脱石是相对不敏感的pH值，离子强度，和类型的可交换阳离子，而高岭石是高度敏感的离子强度。阳离子磺胺二甲嘧啶的吸附蒙脱石超过了1-2个数量级的中性物种，但不重要的高岭石在pH值的检查。阳离子交换似乎有助于阳离子磺酰胺类吸附蒙脱石。阴离子磺胺二甲嘧啶吸附可忽略不计。磺酰胺R基团的性质影响阳离子和中性物质的吸附程度。我们的研究结果强调了在预测这些抗菌剂的运输时考虑磺酰胺形态和粘土表面电荷密度的重要性。
Adsorption of three sulfonamide antimicrobials to clay minerals was investigated as a function of pH, ionic strength, and type of exchangeable cation. Sulfonamide antimicrobial adsorption exhibited pronounced pH dependence consistent with sorbate speciation and clay properties. Sulfonamide antimicrobials did not intercalate into montmorillonite, and surface charge density influenced sorption by determining adsorption domain size. Adsorption edge data were best fit to a model including terms for the cationic and uncharged species. Adsorption of uncharged sulfamethazine to montmorillonite was relatively insensitive to pH, ionic strength, and type of exchangeable cation, while that to kaolinite was highly sensitive to ionic strength. Adsorption of cationic sulfamethazine to montmorillonite exceeded that of the neutral species by 1-2 orders of magnitude, but was unimportant for kaolinite at the pH values examined. Cation exchange appeared to contribute to sorption of cationic sulfonamide species to montmorillonite. Anionic sulfamethazine adsorption was negligible. The nature of the sulfonamide R group influenced the degree of adsorption of cationic and neutral species. Our results highlight the importance of considering sulfonamide speciation and clay surface charge density in predicting the transport of these antimicrobials.