金属离子与8-羟基喹啉类试剂络合物极谱波性质及表面活性剂的作用研究

【作者】 张妮娜；

【导师】 谷学新；

【作者基本信息】 首都师范大学 ， 分析化学， 2003， 硕士

【摘要】 本文研究了金属离子Pd（Ⅱ）、Pb（Ⅱ）、V（Ⅴ）和U（Ⅵ），与8-羟基喹啉类试剂形成的络合物吸附波的极谱行为及表面活性剂对极谱波的影响，主要内容如下： 1．在Na₂CO₃—NaHCO₃（pH 8.6）缓冲溶液中，钯（Ⅱ）与8-羟基喹啉-5-磺酸（8-OXSA）形成的络合物在有阴离子表面活性剂十二烷基硫酸钠（SDS）存在时，于-0.72V（vs．SCE）处有一个二阶导数极谱波，与没有十二烷基硫酸钠存在时相比，峰电流增敏约30倍，钯（Ⅱ）在7.5×10^-9～2.8×10^-6mol/L范围内，i_p″与钯（Ⅱ）的浓度呈线性关系，检出限为2.8×10^-9mol/L，方法用于催化剂和工业废水中钯的测定，结果满意。对极谱波的性质做了初步的讨论，钯（Ⅱ）-8-羟基喹啉-5-磺酸形成的络合物的峰电流具有吸附特性，为不可逆电极反应过程，其电子转移数（n）、电子转移系数（α）及饱和吸附量（Γ_s）分别为2、0.46和2.2×10^-9mol/cm²，钯（Ⅱ）与8-羟基喹啉-5-磺酸的络合比为1：2，稳定常数（K）为8.73×10⁷。加入阴离子表面活性剂十二烷基硫酸钠未形成三元络合物，催化电流是由与SDS共吸附在电极表面上的超氧阴离子自由基氧化了络合物的电极反应中间体所产生的。 2．在H₃BO₄-NaOH（pH9）介质中，当有十二烷基苯磺酸钠（SDBS）存在时，铅（Ⅱ）-8-羟基喹啉（8-OX）配合物于-0.55V（vs.SCE）处有一灵敏的二阶导数极谱波，与没有SDBS存在时相比，灵敏度提高了9倍。峰电流I_p与Pb（Ⅱ）的浓度在1-60ng/mL范围内呈线性关系。回归方程为i_p=0.24+0.090×[Pb²⁺]（ng/mL），r=0.9964，检出限为0.01ng/mL。对极谱波的性质做了初步的讨论，加入阴离子表面活性剂SDBS未形成三元络合物，铅（Ⅱ）与8-羟基喹啉的络合比为1：2，稳定常数（K）为3.5×10¹³。铅（Ⅱ）-8-羟基喹啉形成的络合物的峰电流具有吸附特性，表面活性剂的增敏作用与溶液中的溶解氧具有密切关系。 3．钒（Ⅴ）在pH4.3的邻苯二甲酸氢钾介质中，当有7-碘-8-羟基喹啉-5-磺酸（Ferron）和SDBS存在时，于-0.60V（vs.SCE）处产生一灵敏的二阶导数极谱波，与没有SDBS存在时相比，峰电流增敏14.5倍。峰电流I_p与钒（V）的浓度在0．51 范围内呈线性关系。回归方程为iJ0．027川．031X Nk」h 厂 回归系数 r＝0．9991。钒（V）的检出限为 0．lug／ttiL，方法可用于人发和水样中微量钒的直接测定，结果满意。此外还对极谱波与氧峰电流的相关性做了初步的讨论。 4．铀（＼／l）在PH46的邻苯二甲酸氢钾介质中，当有卜碘十－羟基喳琳卡－磺酸和SDBS存在时，于十．48V（vs石CE）处产生一良好的极谱波，与没有SDBS存在时相比，灵敏度提高了7倍。峰电流I。与铀仰)的浓度在8－100＂g／ffiL、100—600ng／mL及 600l 三个范围内呈线性关系，检出限为0．sng／ttiL。此外还对极谱波与氧峰电流的相关性做了初步的讨论。 文末总结了实验中所发现的具有表面活性剂增敏效果的金属离子－8－羟基睦咐类试剂体系，并对上述体系中增敏作用的一些共性进行了讨论。更多还原

【Abstract】 The polarographic behaviors of metal ion-8-hydroxyquinaldine complex and the enhancement effect of the anionic surfactant of mentioned were investigated. The main points were summarized as follows:1. In the buffer solution of Na2CO3-NaHCO3(pH 8.6), a sensitive oscillopolarographic method for the determination of trace palladium based on the complex adsorptive current of the palladium (II)-8-hydroxyquinoline-5-sulfonic acid (8-OXSA) system with a anionic surfactant, sodium dodecyl sulfate (SDS), was developed. With SDS the current response was increased about 30 times compared to that obtained without SDS and the peak potential was at -0.72V (vs. SCE). Under the optimum experimental conditions the peak current was directly proportional to the concentration of Palladium in the range from 0.8 ng/mL to 300ng/mL and the detection limit was 2.8+10"9mol/L (0.3ng/mL). The method was applied to determination of palladium in catalyst and industrial waste water with satisfactory results. The experiment results demonstrated that the peak current of Pd(II)-8-OXSA behaved an adsorptive character and an irreversible process of electrode reaction, the number of electron (n), the transfer coefficient (a) and the amount of saturated adsorption (fs) were 2, 0.46 and 2. 2+10-9mol/cm2, respectively. It was shown that Pd(II) formed a complex with 8-OXSA with the mole ratio of 1:2, the conditional stability constant was calculated to be 8. 73+107. Ternary complex does not form after adding SDS. Because SDS and superoxide anion radical adsorbed on the electrode surface, the reactive intermediate of Pd(I) -8-OXSA was oxidied by superoxide anion radical and the peak current of the complex was enhanced.2. In the medium of H3BO3-NaOH at pH9 containing sodium dodecyl benzene sulfonate(SDBS), a sensitive peak current of lead(II)-8-hydroxy- quinoline complex was observed at -0.55V (vs SCE) . With SDBS the current response was increased about 9 times compared to that obtained without SDBS. Under the optimum experimental conditions, there is an excellent linearity between peak of current and concentration of lead(II) in the range from 1 ng/mL to 60ng/mL. Thedetection limit is 0.01ng/mL. The linear regression equation is ip=0.24+0.090x[Pb2+] (ng/mL), r=0.9964. Ternary complex does not form after adding SDS. It was shown that lead (II) formed a complex with 8-OX with the mole ratio of 1:2, the conditional stability constant was calculated to be 3.5+1013. The experiment results demonstrated that the peak current of complex behaved an adsorptive character and the enhancement effect of the anionic surfactant is directly related to the superoxide anion radical in the solution.3. In potassium hydrogen phthalate medium at pH4.3 containing Perron and SDBS, a sensitivy current of vanadium ( V ) in second derivative oscillopolarography was observed at -0.60 V (vs. SCE). With SDBS the current response was increased about 14.5 times compared to that obtained without SDBS. The peak current was directly proportional to the concentration of vanadium (V) in the range from 0.5ng/mL to 120ng/mL and the linear regression equation is ip-0. 027+0.031+[V5+] (ng/mL), r = 0.9991. The detection limit was 0.lng/mL and the method was applied to determination of vanadium in hair and in waste water with satisfactory results. In addition, the experiment examined the correlation between peak current of complex and the oxygen in the solution in a preliminary manner.4. In potassium hydrogen phthalate medium at pH4-5 containing Perron and SDBS, a sensitivy current of uranium (VI) in second derivative oscillopolarography was observed at -0.48V (vs. SCE). With SDBS the current response was increased about 7 times compared to that obtained without SDBS. The peak current was directly proportional to the concentration of uranium (VI) in three ranges from 8ng/mL to 100ng/mL, 100ng/mL to 600ng/mL and 600ng/mL to 1000ng/mL. The detection limit was 0.5ng/mL and the correlation between peak current of complex and the oxygen in the solution was also examined in a更多还原