水中典型药物与重金属的络合行为

发布时间：2018-01-19 00:12

本文关键词： 抗生素重金属离子电位滴定酸解离常数络合常数　出处：《东南大学》2016年硕士论文　论文类型：学位论文

【摘要】：在自然水体中,抗生素和重金属的复合污染引起的毒理学效应不容忽视。研究抗生素与重金属络合反应的机理,可以更好地解释抗生素与重金属离子络合对复合污染影响,有利于抗生素与重金属复合污染的防治及污染物质去除。本文采用电位滴定法,研究了三种典型抗生素(四环素TC、环丙沙星CIP和磺胺甲恶唑SMZ)与三种典型重金属离子(Cu2+、pb2+和Cd2+)在水中的络合行为。通过电位滴定实验,计算得出三种典型抗生素的酸解离常数(pKa)及数值,TC的三个酸解离常数分别为pKal=3.38,pKa2=7.54,pKa3=9.36;CIP的两个酸解离常数分别为pKal=6.21,pKa2=8.57;SMZ的两个酸解离常数分别为pKal=1.63,pKa2=6.01。TC存在四种物质状态,分别为H3TC+、H2TC0、HTC-和TC2-；CIP存在三种物质状态,分别为CIP+、CIP0和CIP；SMZ存在三种物质化学状态,分别为SMZ+、SMZ0和SMZ-。另外,通过电位滴定实验,计算得出三种典型抗生素与三种重金属离子的络合物质种类及对应的络合常数(1ogK)。TC-Me络合物质主要为MeHTC+和MeTC0；CIP-Me络合物质主要为MeCIP2+、MeCIP22+和MeCIP2+；SMZ-Me络合物质主要为MeSMZ+。对于三种抗生素,在抗生素-重金属配比(1：1)下,重金属离子(Cu2+、Pb2+和Cd2+)与抗生素的络合能力大小顺序为Cu2+＞pb2+＞Cd2+。对于同一重金属(Cu2+、Pb2+和Cd2+),在抗生素-重金属配比(1：1)下,当水体中3.0pH7.0时,抗生素与重金属络合能力大小顺序为CIPTCSMZ；当水体7.0pH9.0时,抗生素与重金属络合能力大小顺序为TCCIP。以抗生素-Cu体系为例,通过XANES及ATR-FTIR的谱图联合分析,推测抗生素-Me体系络合物质的络合位置。结果表明,TC-Me主要通过C2位上的O、C3位上的O和C11位上的O进行络合；CIP-Me主要通过3位上羧基(-COOH)和4位上的羰基(C=O)进行络合；SMZ-Me主要通过磺胺氧(S=O)和N1位上的N进行络合。
[Abstract]:In natural water, the toxicological effects caused by the compound pollution of antibiotics and heavy metals can not be ignored. The mechanism of complex reaction between antibiotics and heavy metals can not be ignored. The complex effect of antibiotics and heavy metal ions on complex pollution can be better explained, which is beneficial to the prevention and treatment of antibiotic and heavy metal complex pollution and the removal of pollutants. In this paper, potentiometric titration method is used. Three typical antibiotics (tetracycline TC, ciprofloxacin CIP and sulfamethoxazole SMZ) and three typical heavy metal ions (Cu2) were studied. By potentiometric titration experiments, the acid dissociation constants of three typical antibiotics (pKaA) and their values were calculated. The three acid dissociation constants of TC are pKalan3.38, pKa2, 7.54, pKa3O9.36, respectively. The two acid-dissociation constants of CIP were respectively pKalan6.21 and pKa2O8.57; The two acid dissociation constants of SMZ are: pKalan 1.63, pKa2O6.01.TC, H3TC, H2TC0, HTC- and TC2-; There are three kinds of material states in CIP, namely CIP CIP0 and CIP. There are three chemical states in SMZ, namely SMZ, SMZ0 and SMZ-0.In addition, potentiometric titration experiments are carried out. The results show that MeHTC and MeTC0 are the main complexing substances of three typical antibiotics and their corresponding complexing constants: MeHTC and MeTC0. The main compounds of CIP-Me complex are MeCIP2, MeCIP22 and MeCIP2. SMZ-Me complex is mainly MeSMZ. For three antibiotics, heavy metal ion (Cu2) was obtained under the ratio of antibiotics to heavy metals (1: 1). The order of complexation ability of Pb2 and Cd2 with antibiotics was Cu2 > pb2 > Cd2. For the same heavy metal, Cu2, Pb2 and Cd2). Under the ratio of antibiotics to heavy metals (1: 1), when pH was 3.0 pH 7.0, the order of complexation ability between antibiotics and heavy metals was CIPTCSMZ; When the pH of water was 7.0 pH 9.0, the order of complexation ability between antibiotics and heavy metals was TCCIP.The antibiotic Cu system was taken as an example. By the combined analysis of XANES and ATR-FTIR spectra, the complexation sites of antibiotics -Me system were inferred. The results showed that TC-Me mainly passed through O on C2 site. O at C3 and O at C11 are complexed; CIP-Me is mainly complexed by 3 carboxyl-COOH) and 4-carboxyl-Con-(-); SMZ-Me is mainly complexed with N on the N1 site by sulfamethoxy.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X131.2

【相似文献】