Measurement and Preliminary Theoretical Study of Trace Element Concentration and Their Distributions on Different Molecular DOM in Seawater

摘要 痕量元素的含量及其分布在海洋生态系统、海洋环境变化等方面具有关键性的作用。由于海水中金属元素浓度处于痕量水平或更低，加之海水基体复杂，存在仪器灵敏度不足、采样及样品分析过程易玷污等问题，常使用共沉淀、液液萃取、螯合树脂等前处理手段，但这些方法操作复杂、试剂使用量大、方法空白高，很大程度上制约了研究的深入开展。故建立一些准确、方法空白低、精密性好的痕量元素含量及其赋存分布的测定方法，具有重要的海洋学意义。 本研究将聚合物络合超滤技术引入到海水痕量元素分析，利用聚合物对海水中目标元素选择性的络合，实现了基体分离及目标物的富集，随后使用电感耦合等离子体质谱（Inductivelycoupl...Abstract Distribution characteristics and concentration of trace elements in seawater play a crucial role for investigation of marine ecosystem and global biogeochemistry. Because their low concentration and complicated matrix, analysis of trace element in seawater is a challenging field. Hence, the procedure of matrices separation, such as co-precipitation, solvent extraction, and chelating-resi...学位：理学博士院系专业：海洋与环境学院海洋学系_海洋化学学号：2242009015325

Determination of 24 Trace Level of Rare Earth and Metal Elements in Coastal and Estuarine Seawater by Polymer Complexation-Ultrafiltration Technique and Inductively Coupled Plasma Mass Spectrometry

建立了聚丙烯酸螯合-超滤(PCP-uf)分离富集、电感耦合等离子体质谱(ICP-MS)测定海水中痕量稀土及金属元素的方法。PH值高于7.5时,海水中的稀土离子、Cu2+、Pb2+、Cd2+、CO2+、nI2+等与聚丙烯酸(PAA)形成稳定的高分子螯合物,经超滤截留、硝酸解离后,实现了稀土及金属元素从海水中的分离、富集;采用ICP-MS的全定量数据采集模式、内标校正的标准校正曲线法对待测元素进行定量分析。在优化实验条件下,方法的相对标准偏差(rSd)为1.7%~7.3%,加标回收率为73%~96%;方法的定量下限(lOQS,10σ)为0.23~13.9 ng/l,方法空白为0.09~8.38 ng/l。建立的方法可用于近岸及河口海水中痕量稀土及金属元素的同时测定。A method of polyacrylic acid-complexation and ultrafiltration for matrix modification and inductively coupled plasma mass spectrometry(ICP-MS)was developed for the determination of 24 trace level of rare earth elements(REEs) and metal elements in coastal and estuarine seawater.REEs ions,Cu2+,Pb2+,Cd2+,Co2+,Ni2+ could reacted with polyacrylic acid(PAA) to form stable complexes when the pH value was above 7.5,which could be separated and enriched absolutely after trapped and eluted from the ultrafilter.Full quantitative data collection mode and internal standard calibration curve were used for the ICP-MS determination.Under the optimized conditions,the relative standard deviations(RSDs) were in the range of 1.7%-7.3%,and the spiked recoveries were between 73% and 96%.The limits of quantitation(LOQs,10σ) ranged from 0.23 ng/L to 13.9 ng/L.The method blank ranged from 0.09 ng/L to 8.38 ng/L.The developed method could be applied in the simultaneous determination of REEs and metal elements in coastal and estuarine seawater.厦门大学近海海洋环境科学国家重点实验室自主创新项目(MELRI0703

Simultaneous Determination of Ultra-trace Level of As,Sb,Bi,Ge,Sn and Hg in Coastal and Estuarine Seawater by Chemical Vapor Generation and Inductively Coupled Plasma Mass Spectrometry

建立了化学蒸汽发生(CVg)电感耦合等离子体质谱(ICP MS)同时测定近岸及河口海水中超痕量AS、Sb、bI、gE、Sn和Hg元素的方法。研究了CVg过程中kbH4、盐酸和硫脲的浓度以及样品流速、载气流速、海水样品盐度等对方法分析性能的影响。结果表明,在0.70%盐酸、0.10 g/l硫脲、11.0 g/l硼氢化钾、载气0.40 l/MIn条件下,6种待测元素的信噪比最高。优化实验条件下,AS、Sb、bI、gE、Sn和Hg的质量浓度在0.1~5.0μg/l内呈良好线性,相关系数不低于0.996 6;方法对0.1μg/l加标样品的相对标准偏差(rSd,n=5)为3.9%~8.9%,实际海水样品的加标回收率为89%~112%;方法的流程空白为0.012~0.036μg/l,定量下限(lOQS,10σ)在0.006 7~0.026μg/l之间,可满足近岸及河口海水样品中超痕量元素测定的需要。A chemical vapor generation(CVG) and inductively coupled plasma mass spectrometric(ICP MS) method was proposed for the simultaneous determination of ultra-trace level of As,Sb,Bi,Ge,Sn,and Hg in coastal and estuarine seawater.Effects of operating parameters,including concentrations of KBH4,HCl and thiourea,pump flow rate and carrier gas flow rate on analytical performance were studied.The results showed that good signal to noise(S/N) ratios for all the analysed elements were obtained when 0.70% HCl,0.10 g/L thiourea,11.0 g/L KBH4,and 0.40 L/min carrier gas were used in the CVG procedure.The relative standard deviations(RSDs,n=5) for 0.10 μg/L spiked sample were in the range of 3.9%-8.9%.The spiked recoveries for the seawater samples were between 89% and 112%.The method blanks were in the range of 0.012-0.036 μg/L.The limits of quantitation(LOQs,10σ) for the developed method were obtained between 0.006 7 μg/L and 0.026 μg/L.The method could be applied in the simultaneous determination of As,Sb,Bi,Ge,Sn and Hg in coastal and estuarine seawater.近海海洋环境科学国家重点实验室自主创新项目(MELRI0703

A New Method for the Measurement of Complexation Stability Constant and Average Coordination Number of Metallic Element with Polymer

建立了基于化学平衡理论模型以及凝胶过滤色谱(gfC)-电感耦合等离子体质谱(ICPMS)联用技术的高分子聚合物-金属配合物稳定常数、平均配位数测定新方法。以聚乙烯亚胺(PEI)和Cu2+为例,对形成的PEI-Cu配合物稳定常数、平均配位数进行测定,以0.02 MOl·l-1 HAC-nAAC为流动相,凝胶色谱柱分离大分子PEI-Cu配合物以及Cu的小分子配合物、游离态离子,最后用ICPMS测定不同形态金属元素的浓度;利用建立的化学平衡理论模型,计算PEI与金属离子形成配合物的稳定常数、平均配位数,测得25℃,PH4.1~5.3时,PEI-Cu配合物稳定常数为109.6~1010.7,平均配位数为1.0~1.3。建立的在线分离、测定方法具有快速、准确的特点,为高分子聚合物-金属配合物的研究提供新的技术手段。A new method using gel filtration chromatography(GFC) and inductively coupled plasma mass spectrometry(ICPMS) was developed for the measurement of complexation stability constant and average coordination number of the complex of metallic ion with polymer.As an example,the binding of PEI with Cu2+was shown and investigated.The macromolecular PEI-Cu complex and micromolecular species of Cu (Ⅱ) were firstly separated by a low efficiency GFC column with a mobile phase of 0.02 mol·L-1HAc-NaAc buffer,and then directly introduced into ICPMS for elemental analysis.The results of complexation stability constant and average coordination number characterized by putting the concentration of different species of metallic element into the equations of the novel chemical equilibrium model which was developed in this study.The results shown that the complexation stability constants(KPEI-Cu) were between 109.6and 1010.7and the average coordination numbers(n) were in the range of 1.0~1.3 when pH was changed from 4.1 to 5.3 at 25 ℃.This online,rapid and accurate method of GFC-ICPMS is a novel technique for the research of polymer-metallic complex.厦门大学近海海洋环境科学国家重点实验室自主创新项目(MELRI0703)资助项

The Preconcentration,Separation and Purification of Phosphate for the Seawater Dissolved Phosphate Oxygen Isotope Composition Analysis

海水中溶解态磷酸盐的氧同位素组成(δ18OP)是海洋磷循环研究的有效示踪剂之一.海水中溶解态磷酸盐的富集、分离与纯化研究是测定海水磷酸盐氧同位素组成的基础.通过对国内外海水中磷酸盐氧同位素组成的测定方法进行查阅,选择改进后的MAgIC-CEPO4沉淀-阳离子交换树脂法对海水中溶解态磷酸盐进行富集、分离与纯化,并对实验条件进行了探讨.实验结果表明,所采用的方法对于3种不同溶液体系3个步骤的磷酸盐平均回收率分别为92.8%,88.2%和98.3%,全流程磷酸盐回收率达到80%以上,因此可作为海水磷酸盐氧同位素测定的重要前提.Dissolved phosphate oxygen isotope composition(δ18Op) was an effective tracer of ocean phosphate cycle.The preconcentration,separation and purification of phosphate was the foundation of seawater phosphate δ18O analysis.Some popular seawater phosphate δ18O analysis methods were reviewed.Then MAGIC-CePO4 coprecipitation-cation exchange resin separation method was choosed to preconcentrate,separate and purify the phosphate.Some basic experiment conditions were also discussed.The results indicate that the mean phosphate recoveries of three procedures for three systems are 92.8%,88.2%,98.3%,and the total recovery of phosphate is more than 80%,so this method can be served as a basic precondition to determine the oxygen isotope composition of dissolved phosphate in seawater.国家自然科学基金青年项目(40706033);中国大洋协会国际海底区域研究开发“十一五”项目(DYXM-115-02-1-12);厦门大学自选课题(2002xjkt018

Determination of Trace Metal Elements in Coastal and Estuarine Seawater by Polymer-Complexation-Ultrafiltration Technique and Inductively Coupled Plasma Mass Spectrometry

建立了高分子聚合物螯合-超滤(PCP-uf)分离富集、电感耦合等离子体质谱(ICP-MS)测定海水中痕量金属元素的方法。海水中的Cu2+,Pb2+,Cd2+,CO2+,nI2+等金属离子与聚乙烯亚胺(PEI)形成高分子螯合物,经超滤截留、酸解离后,实现金属离子从海水中定量分离、富集。ICP-MS采用全定量数据采集模式、内标校正的标准校正曲线法进行定量分析。在最佳条件下,方法的相对标准偏差(rSd)在3.4%(Cd)~9.3%(Pb)之间(0.20μg/l,n=5),标准加入回收率为78.7%(Ag)~95.2%(Cu);检出限(dl,10&)为1.2 ng/l(Cd)~9.8 ng/l(Cu),空白为1.1 ng/l(Cd,Ag)~9.1 ng/l(Cu)。本方法可应用于近岸及河口海水样品中痕量金属元素的同时测定。A method using polymer-complexation and ultrafiltration for matrix modification and inductively coupled plasma mass spectrometry(ICP-MS) for determination of trace level of metal elements(Cu2 +,Pb2 +, Cd2 +,Ni2 + and Ag +) in coastal and estuarine seawater has been developed.Full quantitative data collection mode and internal standard calibration curve were used for ICP-MS measurement.Under optimized conditions, the relative standard deviations(RSDs) were lower than 9.3%(0.20 μg/L,n = 5),and the standard added recoveries were 78.7%-95.2%.Detection limits(10 &) were from 1.2 ng/L(Cd) to 9.8 ng/L(Cu).The method blank ranged from 1.1 ng/L(Cd,Ag) to 9.1 ng/L(Cu).The developed method has been applied to simultaneously determine the metals in coastal and estuarine seawater.厦门大学近海海洋环境科学国家重点实验室自主创新项目(No.MELRI0703)资