单柱离子色谱法测定碱金属,碱土金属和过渡金属离子

１引言碱金属、碱土金属和过渡金属离子在许多领域有着重要的分析价值。本文采用单柱离子色谱法测定了碱金属、碱土金属和过渡金属离子。以草酸为流动相测定碱金属离子，以草酸－乙二胺为流动相测定碱土金属和过渡金属离子。方法简便、快速、灵敏度、准确。２实验部分２．１主要仪器和试剂ＨＩＣ－６Ａ离子色谱仪（日本岛津），ＣＤＤ－６Ａ电导检测器，Ｃ－ＲＳＡ色谱处理机，５．０ｍｍｉ．ｄ．×１５ＣｍSｈｉｍ－packIC-Cl（阳离子交换柱，Ｐs1４型酸度计。草酸和乙二胺为分析纯试剂，碱金属、碱土金属和过渡金属的氯化物或硝酸盐为优…     

螯合物离子色谱

螯合物离子色谱是一种利用螯合物进行不同方式分离和检测的离子色谱模式，目前已经被痕量金属分析广泛采用，本文对一些螯合物阳离子交换色谱、螯合物色谱、阴离子交换色谱和离子对色谱最新进展进行了综述，并采用基本螯合物化学理论（金属螯合物稳定性、金属原子有效电荷、螯合剂能力等）对保留和分离机理进行了讨论。     

蛋白质在合成阳离子交换剂上的色谱特性研究

用国产材料按间接法合成了螯合型弱阳离子交换剂,详细研究了合成填料的色谱性能,并与商品柱的分离效能进行了比较;在宽温度范围内研究了蛋白质在弱阳离子交换系统中的色谱热力学,测定了蛋白质在色谱过程变性时的热力学参数 (△H0和△S0) 和补偿温度β,提出用标准熵变△S0判断蛋白质的构象变化和用△H0与△S0的补偿关系鉴定蛋白质各变体在色谱系统保留机理的同一性。考察了螯合型弱阳离子交换剂与金属离子的作用,研究了蛋白质在金属螯合色谱中的保留机理。     

阳离子交换色谱中色谱柱温度对碱金属与碱土金属离子保留的影响

研究了非抑制型阳离子交换色谱中色谱柱温度(25~50℃)对碱金属离子(Li+、Na+、K+、Rb+)和碱土金属离子(Mg2+、Ca2+、Sr2+)以及NH4+保留的影响。在Shim-pack IC-C1磺酸型阳离子交换柱上,以硝酸为流动相分离碱金属离子,以乙二胺或乙二胺-草酸(柠檬酸)为流动相分离碱土金属离子,随着色谱柱温度的升高,碱金属和碱土金属离子的保留时间均增长,其范特霍夫曲线具有良好的线性关系,斜率为负值,表明在此条件下碱金属和碱土金属离子的保留为吸热过程。在Shim-pack IC-SC1羧酸型阳离子交换柱上,以硫酸为流动相同时分离碱金属和碱土金属离子,随着色谱柱温度的升高,Mg2+、Ca2+的保留时间增长,而K+、Rb+的保留时间缩短,Li+、Na+、NH4+的保留时间基本不变。在此条件下,Mg2+、Ca2+、K+和Rb+的范特霍夫曲线具有良好的线性关系,其中Mg2+和Ca2+的曲线斜率为负值,K+和Rb+的曲线斜率为正值,表明Mg2+和Ca2+的保留表现为吸热过程,K+和Rb+的保留表现为放热过程。研究表明在不同固定相和流动相条件下,色谱柱温度对碱金属和碱土金属离子保留行为的影响不同。     

电导法检测的过渡金属离子色谱

1980年,James提出了一种具有电导检测器的碱金属和碱土金属单柱阳离子色谱,这种色谱使用了一种特制的交换容量很小的阳离子交换树脂作固定相,很稀的硝酸或乙二胺溶液作流动相。由于巧妙地利用了淋洗离子的当量电导都远大于被淋洗的金属离子,因此在色谱图中,金属离子可以以     

YSC型阳离子色谱分离柱的研制及其性能测定

继Small提出双柱阳离子色谱法(IC)之后,Fritz又提出了不用抑制柱的单柱阳离子色谱法(SCIC),后者所用仪器较为简单。至今,两种方法都已成功地应用于碱金属、碱土金属、铵离子及各种有机胺类的分析。阳离子色谱法的核心是阳离子色谱柱及其填料,我们研制的薄壳磺酸型高效阳离子交换树脂填料,其柱效达到15000片/米,已用于双柱和单柱阳离子色谱分析。     

螯合离子色谱法分析复杂基体中痕量金属离子的研究

发展了应用螯合离子色谱法分析复杂基体中痕量金属离子的新方法。针对不同的检测目的,利用螯合柱（ＭｅｔＰａｃＣＣ－１）和浓缩柱（ＴＭＣ－１）,采用适当的洗脱液在线将基体中的阴离子、一价阳离子、碱土金属离子以及其它干扰离子除去,同时,浓缩富集待测的痕量金属离子,然后再选择适当的梯度淋洗体系,在含有双功能基的分析柱上分离Ｐｂ,Ｃｕ,Ｃｄ,Ｃｏ,Ｚｎ和Ｎｉ等过渡金属离子和１４种镧系金属离子,继而用在线柱后衍生和光度法检测。方法简单快速,样品经适当的酸消解成溶液后即可进样,灵敏度高,检测限为１０－９级甚至更低。     

离子色谱-直接电导法测定碱土金属和过渡金属离子

本文报道离子色谱-直接电导法测定碱土金属和过渡金属离子。研究了流动相pH值、乙二胺浓度及柠檬酸和酒石酸浓度对金属离子分离的影响。结果表明,以乙二胺-柠檬酸为流动相可以同时分离碱土金属和过渡金属离子。用乙二胺-酒石酸作为流动相可以分离碱土金属离子。方法检出限为0.09~1.88 mg/L,加标回收率为97.6%~98.7%。该方法用于叶面肥试样的分析,结果良好。     

离子色谱在稀土及过渡金属分析中的应用

离子色谱是Small等人于1975年发展的一种新的液相色谱分析技术,根据分离方式,离子色谱可分为高效离子色谱(HPIC),离子排斥色谱(HPICE)及流动相离子色谱(MPIC)。现今,离子色谱在环境、能源、化工、冶金、地质、电镀及医疗等方面已得到应用,其专著也陆续出版。 稀土是我国富产元素,是某些磁性材料、超导材料以及高温抗腐蚀合金的组成部分,在国民经济中起着重要作用。在能源及化工领域中需要严格控制过渡金属的含量,以降低有关部件的腐蚀。因此,分析稀土及过渡金属已是十分重要的课题。 用离子色谱法测定稀土及过渡金属具有快速,选择性好,可同时测定多组分及不同价态等特点。     

离子色谱法测定阴离子—基体氯的影响及其消除

离子色谱法简称IC,1975年由Small提出,发展快,应用广,迄今已能分析40多种阴离子,并能测定碱金属、碱土金属及过渡元素,而在阴离子方面尤为突出,已成为阴离子分析的强有力手段。然而目前IC法均应用,多数是浓度低的试样,对     

锆胶基质阳离子色谱柱填料的制备

以10μm锆胶微球包覆聚苯乙烯制成强酸、弱酸型的阳离子色谱柱填料,具有良好的色谱性能。使用D ionex-120型双柱离子色谱仪,较好地分离碱金属、碱土金属离子及铵离子,比较了不同交换基团对溶质保留的影响。由于锆胶基质具有高的化学稳定性和机械强度,用作离子色谱柱填料有良好的应用前景。     

Polymer coated cation exchanger in ion chromatography: preparation, properties and applications

Summary Stationary phases synthesized by polymer-coating of silica gel were investigated for the separation of cations by ion chromatography. Two kinds of polymer coating (polystyrene, polyglycidylmethacrylate) with sulphonic acid cation-exchange groups on various silica gels were prepared. These low capacity strong acid cation-exchangers were applied to determine alkali and alkaline earth metal ions in tap and mineral water, and grape juice samples. The IC-results were compared with those of AAS-measurement and of EDTA-titration of alkali metals and of alkaline earth metals, respectively.     

Simultaneous determination of trace metals by solid phase absorptiometry: application to flow analysis of some rare earths

Solid phase absorptiometry was applied to the simultaneous flow analysis of trace metals in combination with a micro black flow-through cell packed with ion exchanger beads and a multi-channel photodetector connected with optical fibers. A 4.0 cm³ sample solution containing five rare earth metal ions (Dy, Ho, Tm, Er and Nd) was introduced into a flow system and these metal ions were concentrated on a cation exchanger (Muromac 50W-X4) in a flow-through cell. The absorbance increases originating from the f-f or d-f transition bands of these metal ions were directly and continuously measured at 910 nm for Dy, at 530 nm for Ho, at 683 nm for Tm, 522 nm for Er and at 790 nm for Nd, respectively. A multi-variable analysis method was combined with the flow analysis because the absorption spectra of the five rare earth metal ions partly overlapped one another. Although no coloring reagents were used, the proposed method was about ¶200 times more sensitive than the corresponding solution method. The reproducibility of this method was less than ± 5%. The detection limits were 0.03, 0.40, 0.30, 0.35 and 0.23 mg dm^–3 for Dy, Ho, Tm, Er and Nd, respectively. Five rare earth metal ions could be precisely determined in practical samples such as yttrium concentrate.     

Polymer-coated cation exchangers in high-performance ion chromatography: preparation and application

Low-capacity cation-exchange stationary phases for ion chromatography were prepared by coating a vinyl-modified silica gel with polystyrene or poly(glycidyl methacrylate). Strong acid ion-exchange groups were formed by sulphonation with concentrated sulphuric acid or by ring opening of the polymer-coated silica gels with sulphite solution. Carbon-sulphur elemental analyses of the polymer-coated cation exchangers (PCCEs) were applied to determine the average polymer film thickness. The pH stability depended on the polymer film thickness. The PCCEs were stable in the pH range 0.5–9. The low-capacity PCCEs (capacities 18–91 μmol/g) were applied to determine alkali and alkaline earth metal ions in tap and mineral waters.     

Novel weak acid cation-exchange column

A cation-exchange column with carboxylate cation-exchange sites was developed. Compared with conventional surface-sulfonated or latex agglomerated resins, this weak acid cation exchanger has a high selectivity for hydronium ions. Mono- and divalent cations such as alkali and alkaline earth metals can therefore be determined simultaneously in less than 10 min using a weakly acidic eluent under isocratic conditions. Because the ethylvinylbenzene-divinylbenzene substrate is highly cross-linked, the new separator is solvent compatible, thus allowing the use of organic solvents to alter the selectivity of the separation and to remove organic contaminants from the column. The separation characteristics of this column are presented and various applications are discussed.     

Strong complex formation of carbohydrates with metal ions at alkaline pH studied by ligand exchange chromatography

Summary At alkaline pH, carbohydrates are highly retained on a sulphonated polystyrene resin loaded with rare earth or uranyl metal ions. The complex formation is governed by the ionization of the carbohydrate moiety. pH and the type of metal ion were found to have a decisive influence on the complex formation. Binding of the metal ion to the cation exchanger and to different carbohydrates is described. The competitive complexation between solute and hydroxide to the metal ions is described as a ligand exchange reaction and a retention model is proposed. The ligand exchange column was used as precolumn in a coupled column separation system and the high selectivity is demonstrated by the separation of paracetamol glucuronide from a urine sample after filtration and direct injection.     

Simultaneous determination of trace metals by solid phase absorptiometry: application to flow analysis of some rare earths

Solid phase absorptiometry was applied to the simultaneous flow analysis of trace metals in combination with a micro black flow-through cell packed with ion exchanger beads and a multi-channel photodetector connected with optical fibers. A 4.0 cm³ sample solution containing five rare earth metal ions (Dy, Ho, Tm, Er and Nd) was introduced into a flow system and these metal ions were concentrated on a cation exchanger (Muromac 50W-X4) in a flow-through cell. The absorbance increases originating from the f-f or d-f transition bands of these metal ions were directly and continuously measured at 910 nm for Dy, at 530 nm for Ho, at 683 nm for Tm, 522 nm for Er and at 790 nm for Nd, respectively. A multi-variable analysis method was combined with the flow analysis because the absorption spectra of the five rare earth metal ions partly overlapped one another. Although no coloring reagents were used, the proposed method was about ?200 times more sensitive than the corresponding solution method. The reproducibility of this method was less than ± 5%. The detection limits were 0.03, 0.40, 0.30, 0.35 and 0.23 mg dm^–3 for Dy, Ho, Tm, Er and Nd, respectively. Five rare earth metal ions could be precisely determined in practical samples such as yttrium concentrate. Received: 14 March 2000 / Revised: 24 May 2000 / Accepted: 28 May 2000