三步离子交换方法用于粘土沉积物酸溶相中硼同位素测定

在采用酸溶法进行粘土沉积物中硼同位素组成测定时,大量存在的Al、Fe、稀土等元素在较高pH溶液中会形成能强烈吸附硼的氢氧化物沉淀,对硼的提取和硼同位素的测定产生较大影响.有效去除这些干扰元素一直是测定粘土沉积物酸溶相中硼同位素组成的瓶颈.本实验采用三步离子交换法萃取和纯化粘土沉积物中的硼,以AG 50W×8阳离子树脂柱去除所有能生成水不溶性氢氧化物的Al、Fe、稀土等元素,再采用Amberlite IRA 743硼特效树脂柱提取硼,最后采用Ion-exchangerⅡ与AG 50W×8组成的阴阳离子混合树脂柱进一步纯化硼提取液.结果表明,采用以上三步离子交换法提取粘土沉积物中硼的回收率高于90％,未观察到明显的硼同位素分馏,可满足粘土沉积物酸溶相中硼同位素组成高精度测定的需要.     

大气气溶胶中锂的化学分离与同位素比的质谱检测

通过大量条件实验,确定离子交换法分离Li+、Na+的最佳淋洗条件柱填料为Dowex-50w×8阳离子树脂,柱高为12 cm,淋洗液为0.8 mol/mL HCl-50%CH3OH,淋洗速度约为0.48 mL/min.采用离子交换法分离大气气溶胶中Li与其它元素,采用Li3PO3为样品涂样形式的热电离质谱法测量了大气气溶胶中Li的同位素比值.化学分离过程中Li的回收率大于95%,大气气溶胶中稳定Li同位素6Li/7Li比值为0.08206.     

阴离子交换树脂分离富集/电感耦合等离子体质谱测定珊瑚中铅的同位素组成

在自制微型离子交换柱的基础上,建立了阴离子交换树脂AG1-X8分离富集珊瑚中痕量元素Pb的前处理方法,并使用高分辨电感耦合等离子体质谱(HR-ICP-MS)测定了海南橙黄滨珊瑚(porites lutea)样品中的Pb同位素比值。从全程空白值、洗脱曲线、回收率和基体分离情况等方面考察了不同洗脱剂的洗脱效果,结果表明,采用0.50 mol/L HNO3时的洗脱效果最好,方法的全程空白值为18 pg,Pb的回收率为99.6%,在洗脱过程中无拖尾现象,且能与Ca、Sr、Mg、Fe、Mn、Zn、Ba和U等珊瑚中的基体元素成功分离,对上述基体元素的去除率均能达到99.8%以上。使用该方法测得海南珊瑚样品中的207Pb/206Pb、208Pb/206Pb比值分别为0.850 5、2.087 0,相对标准偏差(RSDs,n=21)分别为0.12%和0.11%。该法质量控制良好,表明建立的AG1-X8阴离子交换树脂分离富集/HR-ICP-MS测定珊瑚中Pb的同位素组成的方法可靠,可推广应用于其它复杂样品中铅同位素组成的测定。     

地质样品中Mo同位素测定的前处理方法研究

通过对地质样品中Mo同位素测试前的处理方法的比较,对传统的阴、阳离子树脂交换法进行了改进研究.经改进后的方法实用范围较宽,Mo的回收率达到97.49%±0.27%,Mo同位素质谱分析过程中可能的同重干扰元素Zr、Fe、Mn等的去除效果理想,其它金属元素的去除效果也较理想,且在阴离子交换柱洗脱Mo的过程中总计约需的提取液(盐酸和硝酸)体积只有75mL,只需文献报道用量的45%,从而减少了试剂对样品,特别是对低含量地质样品可能带来的潜在污染.     

离子交换树脂预浓缩法测定环境水中的Cd(Ⅱ)

使用Amberlite CG-120离子交换树脂作为固相萃取剂,预浓缩环境水样中的Cd(Ⅱ),然后用火焰原子吸收分光光度计法(FAAS)测定洗脱液中Cd(Ⅱ)的含量从而确定水样中的Cd(Ⅱ)浓度。实验优化了洗脱液的pH、种类及其浓度、样品和洗脱液流速、吸附剂用量等实验参数,并研究了其他阳离子对Cd(Ⅱ)回收率的干扰效应,获得了最佳的分析灵敏度、准确度、精密度以及回收率。方法检出限为0.1μg/L,线性范围为0.4μg/L～80μg/L。采用该分析方法对自来水、河水、地下水、海水进行加标回收实验,回收率均在95%以上。     

ICP-AES法同时测定树脂样品中的15种金属元素

研究建立了电感耦合等离子体发射光谱法(ICP-AES)同时测定离子交换树脂中Al、Ba、Ca、Co、Cr、Cu、Fe、K、Li、Mg、Mn、Na、Ni、Pb、Zn等15种金属元素的方法,进行了必要的条件试验,选择了分析谱线及其仪器工作参数;考察了无机酸的酸度对测定的影响;在优化条件下,进行了准确度和精密度试验,方法的回收率和精密度分别在87.1%～103.4%和0.5%～5.3%范围,该方法各元素的检出限能满足实验要求,适合离子交换树脂中元素含量的常规分析.     

电感耦合等离子体质谱法测定锆及锆合金中镉含量的质谱干扰分析

通过对Zr及Zr合金中各元素一定浓度单标溶液在电感耦合等离子体质谱(ICP-MS)设定的扫描区间(106~116aum)进行扫描得到质谱图,并结合各元素单标溶液在Cd元素不同同位素质谱峰处的离子计数值的分析,研究了ICP-MS测定Zr及Zr合金中Cd含量时所受的质谱干扰情况,并对干扰物进行了判断。结果表明:基体元素Zr、合金元素Nb和杂质元素Mo所形成的氧化物、氢氧化物多原子离子及合金元素Sn所形成的同质异位素均会对Cd的相关同位素原子构成质谱干扰;针对不同干扰,提出了避免和消除干扰可参考的方法。     

电感耦合等离子体原子发射光谱法测定铜合金中磷

在pH 3～4的微酸性介质中,铜合金试样溶液通过装有强酸性聚苯乙烯型阳离子交换树脂的离子交换柱,分离除去其基体金属阳离子.交换柱流出液(包括洗液)经酸化,蒸发浓缩并定容为25 mL后,用电感耦合等离子体原子发射光谱法测定此溶液中磷(以PO3-4形态存在)的含量.方法的检出限(3σ)为0.026 mg·L-1,用标准加入法测得方法的平均回收率为101.9%.     

多接收等离子质谱高精度测定现代人齿中Mg同位素

Mg是构成牙齿重要组分,其含量和同位素组成可记录居民生活地域、饮食习惯以及口腔健康信息等重要信息.本研究建立了高精度多接收等离子质谱(MC-ICP-MS)测定牙齿中Mg同位素方法.牙齿样品经微波消解仪消解,后采用AG50W-X8阳离子树脂分离溶液中的Mg元素,以1 mol/L HNO3为介质上柱,40 mL1 mol/L HNO3洗脱Na+等杂质离子,再以30 mL 1 mol/L HNO3收集Mg元素,60 mL 1 mol/L HNO3洗去其它杂质,蒸干Mg收集液.MC-ICP-MS进行Mg同位素组成测定.MC-ICP-MS仪器自身的质量分馏利用“样品-标准”交叉技术(“Sample-standard”bracketing technique)解决.实验结果表明,利用AG50W-X8阳离子树脂,可在保证Mg回收率的情况下,将牙齿样品中的Mg和其它基质元素彻底分离,且不造成同位素分馏.采用此方法对现代人离体牙牙釉质中Mg同位素进行分离测定,牙齿的δ25Mg在较大的范围变化(-1.38‰ ～4.59‰).本方法为利用人牙齿中Mg同位素研究Mg的暴露水平、环境污染等信息提供重要的实验和理论依据.     

有孔虫中硼的分离及其正热电离质谱法测定

针对大洋钻探计划(0DP)钻孔中有孔虫数量少、硼含量低的特点，改进了硼特效树脂和阴、阳混合离子交换树脂相结合进行分离硼的方法，成功地实现了硼的分离，并且首次采用正热电离质语法测定了有孔虫中硼同位素的比值。由于硼的分离过程不产生同位素分馏，测定结果令人满意。     

The use of amphoteric ion exchange resin for the selective separation of cadmium from other radioelements present in neutron irradiated biological materials

A new method for the selective radiochemical separation of cadmium from other elements, present in biological materials, using amphoteric ion exchange resin Retardion 11A8 has been elaborated. Cadmium can be taken up by the resin either as anionic chloride complexes or cationic ammine complexes, depending on the composition of the eluent, exploiting both cation and anion exchange functions of the ion exchanger. The conditions in which Cd is quantitatively retained and eluted from Retardion 11A8 were established. The method of selective isolation of cadmium was further used for the determination of Cd in three biological certified reference materials by neutron activation analysis. Analytical results obtained with the use of the proposed separation procedure show good agreement with the certified values.     

Microwave Assisted Benign Method of Chelating Resin Synthesis Having Different Thermal and Ion Exchange Properties

Summary: Microwave irradiation method was used for synthesis of chelating ion exchange resin derived fom Salicylicacid-Formaldehyde-Resorcinol (SFR-M). The resin was characterized by Elemental analysis, FTIR, TGA and SEM. The Broido and Horowitz-Metzger method were used to calculate the energy of activation (Ea) from TGA. The microwave assisted chelating resin has different thermal behaviour as compared to conventional resin (SFR-C). The sorption capacities of microwave SFR resin for transition metal ions are higher than conventional SFR resin. The separation of binary mixtures [Cu (II) and Zn (II)] in brass and [Ni (II) and Cd (II)] were successfully carried out using Kd value.     

Synthesis,characterisation and ion exchange properties of hybrid organic–inorganic composite material: polyacrylamide zirconium (IV) iodosulphosalicylate

ABSTRACT

Contamination of groundwater by heavy metal is one of the most emerging and serious environmental problems. There are so many methods which are available to overcome these problems. Among various available methods, hybrid organic–inorganic ion exchange resin has become more popular due to certain advantages over other available conventional methods; hence, in the present proposed work, we synthesised a hybrid organic–inorganic composite material polyacrylamide zirconium (IV) iodosulphosalicylate by using the sol-gel technique. Synthesised resin was characterised by various methods like Infrared spectroscopy and Thermogravimetric analysis-Differential thermal analysis. Various samples of this ion exchange resin are prepared by changing the condition of synthesis, i.e. concentration of acrylamide to rationalise the ion exchange capacity of the synthesise hybrid organic–inorganic ion exchange resins. A mixture of 0.1 M potassium iodate, 0.1 M sulphosalicylic acid and 0.1 M acrylamide was added dropwise to 0.4 M zirconium oxychloride accompanied by constant stirring for 8 h using magnetic stirrer at 70°C to yield polyacrylamide zirconium (IV) iodosulphosalicylate with maximum ion exchange capacity. Ion exchange capacity of synthesised resin was determined by column method and the maximum ion exchange capacity was found for Pb(II). Determination of k_d values shows that the resin was highly selective for Pb (II).The selectivity for Pb was also evaluated by using certain binary mixture separation such as Ni (II)-Pb(II), Cu(II)-Pb(II), Cd(II)-Pb(II), Sr(II)-Pb(II), Ba(II)-Pb(II),Zn(II)-Pb(II) and Mg(II)-Pb(II).     

The use of Retardion 11A8 amphoteric ion exchange resin for the the separation and determination of cadmium and zinc in geological and environmental materials by neutron activation analysis

A method for the determination of cadmium and zinc in geological and environmental materials by radiochemical neutron activation analysis is presented. It is based on the isolation of the analytes using the amphoteric ion exchange resin Retardion 11A8. The elaborated ion exchange procedure is accomplished both before and after neutron activation. Depending on the eluent composition Retardion 11A8 acts as an anion or a cation exchanger. The method was tested by determining Cd and Zn in two reference materials: Lake Sediment (SL-1) and Zinnwaldite ZW-C. The results of quantitative determinations show good agreement with the certified values.     

Automated separation and preconcentration of copper(II) from natural waters using a column treatment

Summary A comparison is made between two automated column procedures for the separation and preconcentration of Cu(II) from natural waters. The column materials were: an anion-exchange resin and 8-hydroxyquinoline immobilized on a glass support. 8-Hydroxyquinoline showed about the same performance as the ion exchange resin, but was less time and labour consuming. Cu(II) determinations at the ppb level were checked with standard additions and the results were moreover compared with those obtained by another method.On leave from Lisbon University, Portugal     

Determination of cadmium using radiochemical neutron activation analysis

A method has been developed for the determination of cadmium in samples of food and biological materials using neutron activation analysis with radiochemical separation. The irradiated sample is digested in presence of cadmium carrier, with a nitric-perchloric mixture, evaporated to dryness, dissolved in 6M HCl and placed onto an ion exchange column loaded with Dowex 1-X8 resin in chloride form and conditioned with HCl 6M. The cadmium is retained in the resin. After a washing procedure with several portions of HCl of decreasing concentration, the cadmium is eluted with an ammonia-ammonium chloride buffer. The activity of ^115mIn which is in equilibrium with ¹¹⁵Cd, is measured using a NaI(Tl) well type detector. The method has been evaluated by analyzing certified reference materials with cadmium concentrations covering a range of 0.020 to 200 mg^.kg^-1. The agreement of the results with the certified values is within 95%, which gives an indication of the sensitivity and accuracy of the proposed method.     

用离子交换法从植物水提液中纯化分离左旋多巴的研究

本文比较了D290、D296、D370、D301、201×4、201×7等6种树脂对植物水提液中左旋多巴的静态交换和动态交换性能。筛选出D296用以研究不同pH、不同流速、不同解吸剂对吸附交换或解吸交换的影响。实验结果表明：用此工艺得到的产品，有关质量符合药典要求，收率可达4．0％以上。     

Metal Ions Uptake by Chelating Resin Derived from o-Substituted Benzoic Acid and its Synthesis,Characterization and Properties

Summary: Chelating resin [AFM] was synthesized by condensation of Anthranilic acid, Formaldehyde with m-Cresol. The chelating resin was characterized by FTIR Spectra, Elemental Analysis and SEM Photographs. The thermal behavior of the resin was characterized by TGA. The thermodynamic parameters such as Activation Energy (E_a), Order of decomposition (n), Entropy of decomposition (S*), Enthalpy (H*) and Free energy (G*) were calculated by Coats and Redfern method using TGA graph. The chelating behaviour of the prepared resin was studied out with using some metal ions [Ni(II), Cu(II), Zn(II), Cd(II) and Pb(II)]. The sorption capacities of metal ions is found in the following order, Pb(II) < Zn(II) < Cd(II) < Cu(II) < Ni(II). The rate of half exchange was rapid t_1/2 < 20 min for lead ion. The separation of binary mixtures [Cu(II) and Zn(II) in brass and Pb(II) and Cd(II)] was successfully carried out using K_d value.     

Synthesis, charecterization and chelation ion-exchange studies of a resin copolymer derived from 8-hydroxyquinoline-formaldehyde-catechol

A chelating ion exchange resin was synthesized from 8-hydroxyquinoline and catechol using formaldehyde as a cross linking agent at 120 ± 2 °C in DMF solution. The resin was characterized by FTIR and elemental analysis. The morphology of the synthesized resin was studied by optical photograph and scanning electron microscopy (SEM). Various kinetic parameters such as energy of activation (E_a), enthalpy of activation (H?), entropy of activation (S?), free energy of activation (G?), order of reaction (n) and pre-exponential factor (A) of various steps of thermal decomposition have been calculated from thermogravimertic results. The physico-chemical properties of the resin have been studied. The total cation exchange capacity was measured and effect of pH and metal ion concentration on ion exchange capacity were studied. The rate of cation exchange reactions and distribution coefficient values in tartaric acid media at different pH were also studied using batch equilibration method.     

一种具有二甲酚橙基团的新螯合形成树脂及其应用

本文介绍了一种用二甲酚橙(XO)溶液与强碱性阴离子树脂以简便的搅拌方式,制得具有XO基团的新螯合形成树脂的方法。研究了XO树脂的一些性能以及对重全属离子的吸着和洗脱,并用原子吸收测定天然水中Cu、Zn、Cd、Fe元素。同时试验了干扰影响。