【作者】 赵晓红；

【导师】 闫永胜；

【作者基本信息】 江苏大学 ， 清洁能源与环境保护， 2011， 博士

【摘要】 进入新世纪以来,人们已经逐步意识到环境中持久性污染物(主要是指金属污染物和抗生素残留)在土壤、大气、水源中沉积对环境及人类健康所产生的危害。金属污染物不易被生物降解,相反却能在食物链的生物放大作用下,成千百倍地富集,在水体中具有持久的危害性。同时随着污染物的迁移转化,有毒金属离子通过食物链进入生物体内,并不断累积,进而破坏生态系统、危害人体健康。抗生素药物在临床、养殖业和农业中的大量使用,一方面会通过动物体内的残留转移到人体,另一方面动物、禽类产生的耐药菌也会传播给人类,给人类的健康和生存带来严重危胁。对于环境样品的分析,样品的前处理是重要环节,液-液萃取、固相萃取是常用的环境样品前处理方法,但是这两种方法或使用挥发性有机溶剂造成二次污染；或处理成本高；或操作繁琐、富集倍数有限,使其应用受到限制。因而,建立高效、无毒、无污染的绿色分离/富集方法尤为重要。因此,本文建立了绿色无毒双水相萃取体系(小分子醇-盐双水相体系),并将其应用在环境中持久性污染物的分离与富集中；同时,建立溶剂浮选技术与光谱法联用分离/富集环境中痕量重金属残留；再次,创建一种集双水相体系与气浮溶剂浮选法相结合的新的绿色分离/富集体系——双水相气浮溶剂浮选(Aqueous two-phase gas solvent sublation, ATGS),并将该体系利用在环境持久性污染物的分析与检测中。本课题主要从以下三个方面进行研究：(1)双水相萃取技术分离/富集环境中持久性污染物a.以火焰原子吸收光谱法(FAAS)为检测手段,研究了乙醇-硫酸铵双水相萃取镉的主要影响因素,并且利用FT-IR光谱,对其萃取机理进行了初步的探讨。实验结果表明,Cd(Ⅱ)与I-、结晶紫在pH 5.0-6.0的乙醇-硫酸铵双水相体系中形成稳定的紫色配合物。当在最佳条件下时,Cd(Ⅱ)的萃取率达到100.00%。该方法校准曲线线性范围为0～0.500μg/mL,相关线性系数为0.9993,方法检出限为0.012μg·mL-1。用于环境水样中镉含量的测定,相对标准偏差为2.8%～3.6%,加标回收率大于95.00%。b.在沸水浴加热下,Zn(Ⅱ)对氨苄西林的降解反应具有催化作用,其降解产物可产生荧光。据此建立了一种正丁醇-盐-水双水相体系,萃取间接荧光光度法测定环境中痕量氨苄西林的方法。考察了正丁醇中加入盐的种类、盐用量、Zn(Ⅱ)离子浓度、加热时间及温度对萃取率的影响,优化了萃取条件。氨苄西林降解物浓度在5×10-6～9.0×10-5 mol·L-1范围内与荧光强度呈线性关系,方法检出限为5.16×10-10mol·L-1。且正丁醇萃取氨苄西林降解物富集倍数高(达26倍),试剂用量少,在优化试验条件下实测了长江水、井水、玉带河水样,回收率为94.5%～100.2%。该方法适合于环境水样中氨苄西林的分析测定。(2)溶剂浮选技术与光谱法联用分离／富集重金属残留a.在酸性条件下,Cr(Ⅵ)能将二苯碳酰二肼(DPC)氧化成紫红色二苯偶氮碳酰,自身被还原为Cr(Ⅱ),Cr(Ⅲ)可与二苯偶氮碳酰生成深紫红色Cr(Ⅲ)—二苯偶氮碳酰配合物,该配位化合物在水相中不易溶解且不稳定,而在有机溶剂苯中稳定且极易溶于苯,利用此特性用N2将Cr(Ⅲ)一二苯偶氮碳酰配合物浮选于苯中,形成真溶液,通过测定有机相吸光度测定溶液中Cr(Ⅵ)含量(λmax=540nm)。用过硫酸铵(少许AgNO3催化)将溶液中Cr(Ⅲ)氧化成Cr(Ⅵ),同法测定Cr(Ⅵ)+Cr (Ⅲ) (∑Cr)含量,差减法计算出Cr(Ⅲ)含量。由于采用了大的富集倍数,使灵敏度大大提高,ε540=4.2×105L·mol-1·cm-1,比水相光度法提高10倍,50 mL溶液中,线性范围0～12μg/50mL。测定2.0μgCr(Ⅵ),RSD=1.80%,方法检出限7.1×10-9mol·L-1,由于络合和浮选的选择性,使本法选择性极强(大多数共存离子不影响测定)。b.Mn(Ⅱ)与1,10-二氮杂菲(phen)能生成稳定的配位阳离子[Mn(Phen)3]2+,该阳离子能与碱性染料四碘荧光素(TIF)缔合生成缔合物Mn(phen)3(TIF)2,该缔合物在水中不稳定,但在有机溶剂中稳定且极易溶于有机溶剂,基此用N2浮选三元缔合物于苯中,建立了光度法测定锰的新方法。本法灵敏度高(ε=9.6×105L·mol-1·cm-1),对4.0μg/200mL锰测定6次,测定的RSD=2.3%,检出限为0.5μg·L-1,适用于天然水和酒中锰的测定。c.Cu(Ⅱ)易与铜试剂二乙基二硫代氨基甲酸钠(NaDDTC)形成配合物Cu(DDTC)2,该配合物不溶于水且在水中不稳定,而在有机溶剂中稳定,且易溶于有机溶剂,基此建立了基于N2浮选Cu(DDTC)2于苯中的溶剂浮选光度法测定铜的新方法。本法灵敏度高(ε435=2.9×105L·mol-1·cm-1),精密度理想(测定5μg/400mL Cu(Ⅱ)6次,RSD=2.0%),检出限低(400 mL浮选体积检出限2.8×10-2μg·L-1)。适于天然水中痕量铜测定。d.Pb2+易与I-形成[PbI4]2-(?)配阴离子,该阴离子可与罗丹明B(RhB+)等阳离子碱性染料形成三元缔合物。该三元体系在水中不稳定,而在有机溶剂中较稳定,基此建立了N2浮选Pb(Ⅱ)—I-—RhB+体系于苯中的溶剂浮选三元配合物测铅新方法,本法灵敏度高(ε=2.2×105L·mol-1·cm-1),选择性好(不同氰化物掩蔽),精密度理想(测定5μg铅10次,RSD=1.7%),实测了半导体厂处理前电镀废水。(3)双水相气浮溶剂浮选分离/富集环境中持久性污染物a.结合气浮溶剂浮选和双水相萃取(ATPE)的优点,建立了一种新的分离/富集的方法,双水相气浮溶剂浮选(ATGS),并用于环境中痕量Cd(Ⅱ)的分离/富集.同时,以火焰原子吸收光谱(FAAS)检测Cd(Ⅱ),考察了浮选时间、N2流速、丙醇的分相条件、pH和配合剂用量等因素对浮选Cd(Ⅱ)的影响.最后优化出最佳浮选条件和测定条件,并探讨了共存离子对Cd(Ⅱ)浮选的干扰情况。结果表明,2 mol·L-1的KI9.5mL, 1g·L-1的罗丹明B 2.5 mL,盐体积分数为46%,缔合时间17min,气浮流速20 mL·min-1,浮选率可达100%,富集倍数为10,优于单一的双水相萃取。Cd(Ⅱ)含量在0.050-5.000 mg·L-1与吸光度呈线性关系,线性方程为F=2.8967C-0.1474,相关系数为0.9996,检出限为0.0113 mg·L-1,相对标准偏差RSD为1.8%(n=15)。b.离子液体[Bmim]BF4-无机盐体系浮选红霉素的最优化浮选条件：当显色剂为75%硫酸,反应时间30 mmin,此时浮选完的富含[Bmim]BF4的上相具有荧光性,可用于ROX和ACE的定量分析。当选择降低浮选溶剂[Bmim]BF4粘度的溶剂为H2O, V[Bmim]BF4:VH2O=1:1时,可有效的降低[Bmim]BF4的粘度,使其作为良好的浮选溶剂。当浮选池体积为50 mL,对于ROX, Na2CO3的浓度为为0.32 g·mL-1,试液pH=11.5；对于ACE, (NH4)2SO4的浓度为0.54 g·mL-1,pH值为5.5。两种浮选体系的气体流速15 mL·min-1,浮选时间50 min,在优化条件下气浮溶剂浮选,浮选率为75%～85%(ROX)和80%-90%(ACE),富集倍数21.25(ROX); 22.5(ACE),分配系数为100和141。更多还原

【Abstract】 In the new century, people have gradually realized that the sediment of the environmental persistent pollutants (mainly refers to the metal contaminants and antibiotic residues) in the soil, air, and water have damaged to the environment and human health. Metal pollutants can not easily be biodegradable; on the contrary they are able to biomagnification in the food chain, and enrich with the thousands of times. So that metal pollutants have a long-lasting harm in the water. At the same time, as the migration and transformation of pollutants, toxic metal ions enter into the living body through the food chain and accumulate, thus upset the equilibrium of the ecosystem and endanger human body health. Antibiotics are used in large amounts in clinical, aquaculture and agriculture. On the one hand, antibiotics transfer to the human body through the residues of the animals; On the other hand, birds also produce resistant strains which transmitted to humans. It is a serious threat to human health and existence. For the analysis of environmental samples, the sample pretreatment is an important aspect. Liquid-liquid extraction and solid phase extraction are the common environmental sample pretreatment methods. However, the methods are still undesirable for most analyses due to consumption of time and a large amount of volatile, toxic, pollution organic solvents. Additionally, these method can cause secondary pollution and high cost. Thus, the establishment of efficient, nontoxic, pollution-free and green separation/enrichment method is particularly important. Therefore, we established a green and non-toxic aqueous two-phase system (small molecular alcohol-salt aqueous two-phase system) to separate and concentrate the environmental persistent pollutants. Meanwhile, we also established a method which combined solvent sublation with spectrum method to separate/concentrate trace heavy metals in the environment. Once again, we created a new and green separation and concentration system which combined aqueous two-phase system and solvent sublation:Aqueous two-phase gas solvent sublation. And we used this system to analyse and detect the environmental persistent pollutants. The main subject of study from the following three aspects:(1) Separation and concentration the environmental persistent pollutants by aqueous two-phase extractiona. A new method for extraction of Cd(Ⅱ) by aqueous two-phase system with ethanol-(NH4)2SO4 was investigated. The main factors for Cd(Ⅱ) extraction and extraction mechanism were investigated with flame atomic absorption spectrometry (FAAS) FT-IR spectrum, respectively. The results showed that Cd(Ⅱ), I- and crystal violet could form a purple stable complex in the aqueous two-phase system of ethanol-(NH4)2SO4 while the pH value ranges from 5.0 to 6.0. Under the optimum conditions, the extraction yield of Cd(Ⅱ) reached 100.00%. The linear range was from 0 to 0.500μg·mL-1, and correlation coefficient of linear was 0.99926 with a RSD of 2.8%, and the detection limit of Cd(II) was 0.012μg·mL-1. Then the method was applied to the determination of Cd(Ⅱ) in actual water samples, and the satisfactory recovery (>95.00%) was obtained.b. An extraction indirect fluorophotometric method for determination of trace ampicillin was established in this paper. The method was based on the ampicillin degradation catalyzed by Zn (Ⅱ) ions with boiling water bath, the degradation product can be extracted with a n-butanol-salt-water two-phase system, and then the fluorescence intensity of the degration product was determined by spectrofluorimetry. The experimental conditions, such as the types of salts, the concentrations of K2CO3 and Zn (Ⅱ) ion, as well as heating temperature and time, were discussed and optimized. Linear range was from 5×10-6 to 9.0×10-5 mol·L-1, and the detection limit was 5.16×10-10 mol·L-1。The enrichment factor of this method can reach 26 times and a few of n-butanol is used. Under the optimum conditions, this method could be successfully applied for the analysis of Chang Jiang water, Well water and yu dai river water and the recoveries were in the range of 94.5%～100.2%. The method has been applied to the determination of trace ampicillin in water sample of the environment.(2) Separation and concentration the heavy metals by a method which combined solvent sublation with spectrum methoda. It is based on that diphenylcarbzide (DPC) can be oxidized by chromium (Ⅵ) to amaranthine diphenylcarbazone, which can associate with chromium (Ⅲ) to form a claret chromium (Ⅲ)-diphenylcar bazone complex in acid medium. This ternary complex has bad solubility and instability in water phase, whereas it can be dissolved easily in organic solvent of benzene with good stability and floated by N2 into benzene to form a real solution. Chromium (Ⅵ) content is determined in the solution by measuring the absorbance of organic phase. Then chromium (Ⅲ) is oxidized into chromium (Ⅵ) by ammonium persulfate and the total chromium can be determined by the same way, so that chromium (Ⅲ) content can be calculated by minus. The sensitivity of this method is improved about 10 times higher than that of water phase spectrophotometry through large dose enrichment. The apparent molar absorptivity is 4.2×105L·mol-1·cm-1, Beer’s law is obeyed in the range of 0～12μg/50 mL for Cr (VI). The relative standard deviation is 1.80%, the detection limit is 7.1×10-9mol/L, Because of the selectivity of the complexation and flotation, the method has highly good selectivity (most coexistence ions don’t interfere with the determination).b. Mn(Ⅱ) and 1,10-phenanthroline can form a stable coordinated cation [Mn(phen)3]2+, this cation can generate association complex Mn(phen)3(TIF)2 with basic dyes four iodine fluorescence (TIF). This association complex is unstable in water, but it is stable and easy dissolves in organic solvent. So a new method that ternary associated complex was flotated into the solution of benzene by N2 was established for the determination of Mn by photometry. The sensitivity of this method is high (8=9.6×105L·mol-1·cm-1), the relative standard deviation is 2.3% by measured six times of 4.0μg/200mL of Mn and the detection limit is 0.5μg·L-1. The method is suitable for the determination of Mn in natural water and wine.c. Cu(Ⅱ) and sodium diethyldithiocarbamate can form a coordination compound Cu(DDTC)2. The coordination compound is insoluble and unstable in water, while it is soluble and stable in organic solvent. So a new method that Cu(DDTC)2 was flotated into the solution of benzene by N2 was established for the determination of Cu by solvent flotation photometry. The sensitivity of this method is high (ε435=2.9×105L·mol-1·cm-1), the accuracy is satisfactory that the relative standard deviation is 2.0% by measured six times of 5μg/400mL of Cu(II), the limit of detection (LOD) is low that the LOD is 2.8×10-2μg·L-1when the flotation volume is 400 mL. The method is suitable for the determination of trace Cu in natural water.d. Pb2+ and I- can form a coordinated anion [PbI4]2-, this anion can generate ternary associated complex with basic dyes rhodamine B(RhB+). The ternary system is unstable in water, but stable in organic solvent. So a new method that Pb(Ⅱ)——I-——RhB+ system was flotated into the solution of benzene by N2 was established for the determination of Pb by solvent flotation. The sensitivity of this method is high (ε=2.2×105L·mol-1·cm-1), the selectivity is good and the accuracy is satisfactory that the relative standard deviation is 1.7% by measured ten times of 5μg of Pb. The electroplating wastewater before treatment was detected in semiconductor factory.(3) Separation and concentration the environmental persistent pollutants by aqueous two-phase gas solvent sublationa. Combining solvent sublation with aqueous two-phase extraction (ATPE), a new preconcentration/separation method was established:aqueous two-phase gas solvent sublation (ATGS). Then ATGS was applied to preconcentrate/separate Cd (Ⅱ) in the environment prior to flame atomic absorption spectrometric determination. The effects of analytical parameters including pH, proper condition of phase separation, volume of complex reagent and flotation time on the recoveries of heavy metals were investigated. The recovery of Cd (Ⅱ) was 100%. Cadmium was concentrated 10 times using this method, which is much better than aqueous two-phase extraction alone. For concentrations of Cd (Ⅱ) from 0.050 mg·L-1 to 5.000 mg·L-1, the linear equation was F= 2.8967C-0.1474 and the linear correlation coefficient (R2) was 0. 9996. The detection limit of Cd (Ⅱ) was 0.0113 mg·L-1. Averaging 15 determinations of 1 mg·L-1 Cd (Ⅱ) gave a relative standard deviation of 1.8%. The proposed method is shown to be promising for preconcentration/separation before the determination of trace and ultra-trace substances.b. Studied on separation/enrichment of erythromycin antibiotic by [Bmim]BF4-inorganic salt aqueous two-phase solvent sublation.Taking [Bmim]BF4 as sublation solvent, color reaction agent was 75% H2SO4, the sublation solvent was [Bmim]BF4-H2O(V[Bmim]BF4:VH2O=1:1), the salting-out agent was Na2CO3 with 0.32 g·mL-1, pH=11.5 for ROX, and (NH4)2SO4with 0.32 g·mL-1, pH= 11.5 for ACE, respectively. The sublation time was 50 min, gas flow rate was 15 mL·min-1. Under the optimum conditions, the sublation efficiency was 75%～85% for ROX with enrichment multiple 21.25 and 80%～90% for ACE with enrichment multiple 22.5, respectively.更多还原