【作者】 王磊；

【导师】 陈建荣；

【作者基本信息】 浙江师范大学 ， 分析化学， 2010， 硕士

【摘要】 双浊点萃取(dual cloud point extraction, dCPE)法是近年出现的一种萃取方法,已用于生命科学和环境科学等领域的研究中。它以传统的一次浊点萃取,即浊点萃取(cloud point extraction, CPE)为基础,通过加入反萃取试剂,再次经过恒温和离心,将一次浊点萃取物中的待测成分由表面活性剂富集相转移到水相,并进行检测分析。实验中的重要参数,如溶液的酸碱度(pH)、离子强度、温度等引发相分离,使疏水性物质与亲水性物质分离。该技术具有简便、安全、高效和低廉等优点,近年来已成功地用于酚类、植物激素和汞类的分离富集,并与毛细管电泳(Capillary Electrophoresis, CE)联用。但是,有关与电感耦合等离子体-原子发射光谱(Inductively Coupled Plasma-Atomic Emission Spectrometry, ICP-AES)联用的报道较少。本论文的目的是建立一种用于环境水样中多种痕量金属元素测定的方法,通过双浊点萃取技术对环境水样中痕量金属元素进行预富集,用ICP-AES进行测试,以达到同时检测环境水样中多种元素含量的目的,且获得较高的灵敏度、准确性和较低的检测限。实验分为两个部分：1.选择1-(2-吡啶偶氮)-2-萘酚(1-(2-pyridylazo)-2-naphthol, PAN)作螯合剂,TritonX-114作萃取剂,HNO3作反萃取剂,对Cd、Ni、Pb、Zn、Cu和Mn进行双浊点萃取。优化pH、反萃取剂浓度、缓冲溶液用量、PAN浓度、TritonX-114浓度、平衡温度和时间、离心时间、离子强度和干扰离子等影响因素。在pH 10,2mLHNO3浓度为2mol L-1, PAN浓度为1.96×10-5 mol L-1, TritonX-114浓度为0.1%条件下,对Cd、Ni、Pb、Zn、Cu和Mn进行分离和预富集测定,各元素工作曲线的R2均在0.9494以上,富集倍率分别为17.88,20.66,24.24,16.79,19.33和19.97,检测限分别为0.0004,0.001.6,0.0079,0.0018,0.0015和0.0013μgmL-1。方法用于自来水、婺江水及校园湖水中痕量金属元素的测定,结果令人满意。2.选择二乙基二硫代氨基甲酸钠(Sodium diethyldithiocarbamatre, DDTC)作螯合剂,TritonX-114作萃取剂,HNO3作反萃取剂,对Cd、Ni、Zn、Cu和Fe进行双浊点萃取,优化pH、反萃取剂浓度、缓冲溶液用量、DDTC浓度、TritonX-114浓度、平衡温度和时间、离心时间、离子强度和干扰离子等影响因素。在pH 6,2mLHNO3浓度为2mol L-1, DDTC浓度为5×10-4 mgmL-1, TritonX-114浓度为0.1%条件下,对Cd、Ni、Zn、Cu和Fe进行预富集分离测定,其工作曲线的R2均在0.9915以上,富集倍率分别为17.72,18.33,15.96,18.95和16.58,检测限分别为0.0001,0.0004,0.0005,0.0024和0.0021μg mL-1。方法用于自来水、婺江水及校园湖水中痕量金属元素的测定,结果令人满意。更多还原

【Abstract】 A novel dual cloud point extraction (dCPE) was developed recently which has played important roles in the field of life science and environmental science. A procedure for dCPE was based on conventional method called cloud point extraction (CPE). Back-extraction reagent was added after the first CPE, then the system underwent heating and centrifugation, and analytes were also seperated from hydrophobic phase to hydrophilic phase. At last, analytes were analyzed by modern chemical instruments. The two phases were separated, which resulted from the effect of experimental conditions such as pH, ionic strength and temperature, etc. dCPE is an easy, safe, high efficiency and inexpensive methodology for separation and preconcentration. The dCPE technique has been applied in the chemical substances, such as phenols, auxin, and mercury classes, and also combined with capillary electrophoresis. However, based on dCPE-ICP-AES in trace anaiysis has seldom been reported. A new method for the determination of trace elements in environmental water was proposed in this paper. Firstly, trace elements in environmental water were preconcentrated though dCPE mentioned above; secondly, preconcentrated elements were detected by ICP-AES simultaneously. Satisfaction results were obtained, such as high sensitivity, veracity, and low limits of detection (LOD).This present experiment consists of two parts as follow:1. 1-(2-pyridylazo)-2-naphthol was used as chelating reagent, TritonX-114 as surfactant and HNO3 as back-extraction reagent for the dCPE of Cd, Ni, Pb, Zn, Cu and Mn. Then the effect of experimental conditions was optimized, such as pH, back-extration reagent concentration, buffer solution dosage, PAN concentration, TritonX-114 concentration, equilibration temperature and time, centrifugation time, ion strength and interference ions, etc. Under the optimum conditions, dCPE in the presence of pH 10,2 mL back-extraction reagent HNO3 concentration 2 mol L-1, PAN concentration 1.96×10-5 mol L-1, TritonX-114 concentration 0.1%permitted the preconcentrated factors of 17.88,20.66,24.24,16.79,19.33 and 19.97, and the detection of 0.0004,0.0016,0.0079,0.0018,0.0015 and 0.0013μg mL-1 for Cd, Ni, Pb, Zn, Cu and Mn, respectively. All the elements’R2 were more than 0.9494. The proposed method was applied to the determination in water sample, such as tap water, river and lake with satisfactory results.2. Cd, Ni, Zn, Cu and Fe reacted with DDTC followed by the first experiment idea and procedure, and then optimize all the conditions, too. At last, in the presence of pH 10,2 mL back-extraction reagent HNO3 concentration 2 mol L-1, DDTC concentration 5×10-4 g mL-1, TritonX-114 concentration 0.1%permitted the preconcentrated factors of 17.72,18.33,15.96,18.95 and 16.58, and the detection of 0.0001,0.0004,0.0005,0.0024 and 0.0021μg mL-1 for Cd, Ni, Zn, Cu and Fe, respectively. All the elements’R2 were more than 0.9915. The proposed method was applied to the determination in water sample, such as tap water, river and lake with satisfactory results.更多还原