Separation Of Inorganic Ions Research Articles

Ion-Exclusion/Cation-Exchange Chromatography Using Dual-Ion-Exchange Groups for Simultaneous Determination of Inorganic Ionic Nutrients in Fertilizer Solution Samples for the Management of Hydroponic Culture

In this study, ion-exclusion/cation-exchange chromatography (IEC/CEC) using dual-ion-exchange groups (carboxy and sulfo groups) for the simultaneous determination of anions (SO42−, Cl−, NO3−, and HPO42−) and cations (Na+, NH4+, K+, Mg2+, and Ca2+) was developed. By using the combination of dual-ion-exchange groups, simultaneous separation of inorganic ions with HPO42− was achieved that was impossible by the conventional IEC/CEC based on the single-ion-exchange group (carboxy group). This method was applied to the monitoring of inorganic ionic nutrients in fertilizer solution samples in hydroponic culture. As a result, a higher peak resolution of inorganic anions and cations with phosphate ion using IEC/CEC with dual-ion-exchange groups was achieved in the absence of matrix effects. In addition, the developed method helps to understand the behavior of ionic nutrients in fertilizer solution during hydroponic cultivation and is potentially useful for the individual fertilization of ionic nutrients.

High-resolution Arduino-based data acquisition devices for microscale separation systems

In this work, we have designed, constructed, and evaluated simple, inexpensive open-source data acquisition systems based on various analog-to-digital converter modules (ADS 1115, MCP 3424, LTC 2400, with resolution from 16 to 24-bit) and a miniature Arduino Nano ™ microcontroller. The constructed data acquisition systems provide excellent performance and are comparable to a commercial, 24-bit device. We provide full schematics and corresponding source codes so that analytical chemists can easily construct any of the developed systems without extensive electronic or programming knowledge. The 24-bit LTC 2400 based device provided the best and comparable performance to a commercial, high-end 24-bit sigma to delta converter (ORCA 2800) at a fraction of cost (less than 50 USD compared to 870 USD for the commercial counterpart). The excellent performance was verified using a capillary electrophoresis system with contactless conductivity detection and separation of inorganic ions in clinical skin wipe and tap water samples.

Создание первых ионообменников и начало их широкого применения

Представлена история создания ионообменников с конца XIX в до середины XX века. Впервые проанализированы ключевые научные работы этого периода с историко-научной точки зрения. Расследованы ранее неизвестные факты биографии некоторых ученых. Проанализирован цикл работ, положивших начало ионообменной хроматографии

Separation of small organic ions from salts by ion‐exchange membrane in electrodialysis

AbstractElectrodialysis (ED) can be applied in the food and fermentation industry for separating inorganic salts and organic ions from other fractions. However, the separation efficiency for small organic ions should be understood in detail. In this article, the membrane selectivity and transport mechanism of small organic ions from mixed salts by ion‐exchange membranes are theoretically and experimentally investigated. First of all, the influence of current density on the solute flux (organic ions and inorganic ions) and on membrane selectivity (between organic ions and inorganic ions and between different organic ions) in ED has been studied. The selectivity was shown to be influenced by changing the applied current density. It was observed that separation of inorganic ions from organic solutes was feasible, but the selectivity was dependent on the size, charge, and functional groups of the organic ions. Furthermore, results imply that binary organic anions with larger molar mass (>130, i.e., aspartate and tartrate) can be adsorbed onto the membrane free volume and hence form a charged double layer, which affects membrane selectivity. Finally, competition between small organic and inorganic ions is discussed by comparison of the concentration profiles and current efficiencies of the different anions. © 2010 American Institute of Chemical Engineers AIChE J, 2011

Transport of NaCl, MgSO_4, MgCl_2 and Na_2SO_4 across DL type nanofiltration membrane

The separation of inorganic ions by membrane filtration of aqueous solutions through NF-membranes was investigated. The single and binary salt solutions of NaCl, MgCl 2 , Na 2 SO 4 and MgSO 4 were used in this study. These salts are the most commonly found in natural water resources. From the research literature it was stated that NaCl has a very low rejection range with NF membranes while MgCl 2 is moderately rejected, Na 2 SO 4 and MgSO 4 are very highly rejected salts. Thus, these four salts provide a full range of rejection behavior for the NF system and hence constitute an ideal system. In addition, these salts have a very high solubility in water so there would not be any cake layer formed due to precipitation of salts at the surface of the membrane where a significantly higher concentration of salt can be developed due to concentration polarization.

Simultaneous Separation of Inorganic Ions and Neutral Organics on a Sol-Gel-Coated Capillary using Combined Capillary Zone Electrophoresis and Capillary Electrochromatography

Capillary zone electrophoresis was combined with capillary electrochromatography to effect the separation of ionic and neutral organic mixtures. Sol-gel technology was used to coat the capillary wall with a silane-based stationary phase. An n-octyl phase was used for cation-organic mixtures and an octadecyl phase, which incorporated a quaternary ammonium group to effect electroosmotic flow reversal, was employed for anion-organic mixtures. Tetraethoxy silane was used as a spacer to control the density of stationary phase interactive groups. Some data on the optimum ratio of analyte-interactive group to spacer silane in the sol-gel reaction mixture was obtained. Mobile phases were mixtures of typical capillary electrophoresis run buffer and reversed phase chromatography constituents. In all cases, the analytes were separated both within and between classes, the ions exiting the capillary as a group before the neutral organics. Investigation of mobile phase methanol cosolvent and pH effects found that electrophoretic and chromatographic behavior in the mixed mode system was what would be observed in a single mode separation, demonstrating the independence of the two modes. Separation of ions and neutrals in a red wine and multivitamin is demonstrated.

Separation of inorganic ions by high-speed countercurrent chromatography with an aqueous biphasic system

本研究では，水性二相系高速向流クロマトグラフィー（HSCCC）による無機化合物の分離を目的として，操作条件と分離性能の関係を検討した．HSCCC装置としてはJ型コイルプラネット向流クロマトグラフ，水性二相系としてはポリエチレングリコール（PEG）-Na2SO4系を用い，無機陰イオン（IO3－，I－，NO3－，SCN－）をモデル化合物として，二相系の組成，ドラムの回転速度及び移動相流量と分離度の関係を検討した．その結果，カラムを巻き付けたドラムの回転速度が大きいほど固定相保持百分率が減少したが，それにもかかわらず分離度は大きくなるという現象が観測された．理論段数を測定したところ，分離度の増加はほぼ理論段数の増加で説明できることが明らかになった．これは，回転速度の増加に伴って二相のかくはんが激しくなり，液滴が小さくなることによるものと推測される．一方，移動相流量は分離効率に大きな影響を与えなかった．得られた結果に基づいて最適条件を設定し，Cr(III) とCr(VI) の分離を試みたところ良好な分離結果が得られた．

The importance of capillary electrophoresis, capillary electrochromatography, and ion chromatography in separations of inorganic ions.

The importance of capillary electrophoresis (CE), capillary electrochromatography (CEC), and ion chromatography (IC) in inorganic ion analyses is outlined. Methods for improving the reliability of the CE measurements are briefly described. Selectivity optimization in CE analyses of inorganic cations and anions is discussed. Using the Peakmaster program, CE system peaks (system zones, eigenmobilites) and some important CE parameters, such as effective mobilities, electromigration dispersion, indirect UV, and direct conductivity signals, are predicted and compared with experimental analyses.

Optimization of the high-frequency contactless conductivity detector for capillary electrophoresis.

Two constructions of the high-frequency contactless conductivity detector that are fitted to the specific demands of capillary zone electrophoresis are described. The axial arrangement of the electrodes of the conductivity cell with two cylindrical electrodes placed around the outer wall of the capillary column is used. We propose an equivalent electrical model of the axial contactless conductivity cell, which explains the features of its behavior including overshooting phenomena. We give the computer numerical solution of the model enabling simulation of real experimental runs. The role of many parameters can be evaluated in this way, such as the dimension of the separation channel, dimension of the electrodes, length of the gap between electrodes, influence of the shielding, etc. The conception of model allows its use for the optimization of the construction of the conductivity cell, either in the cylindrical format or in the microchip format. The ability of the high-frequency contactless conductivity detector is demonstrated on separation of inorganic ions.

DETERMINATION OF INORGANIC ANIONS BY ELECTROSTATIC ION CHROMATOGRAPHY WITH A CATION EXCHANGE COLUMN AS A PRE-COLUMN FOR CONVERSION OF THE CATIONS INTO A COMMON SPECIES

The problem of “multiple” distribution of the analyte ions encountered in the separation of inorganic ions by electrostatic ion chromatography (EIC) was overcome. EIC is a new type of ion chromatography (IC) where zwitterionic molecules are used as the stationary phase and pure water serves as the mobile phase. Both ions and polar organic compounds can be separated by EIC and the simultaneous electrostatic attraction-repulsion interactions between the positive-negative charges (or polarities) of the analytes and the stationary phase are considered to be the main mechanisms for the separation. In the analysis of inorganic ions by EIC, each species of the cation and/or anion was distributed to all species of the counterion and co-eluted as pairing ions. To avoid such “multiple” distribution of the analyte ions, the analyte cations were converted into a common species of either Na+ or Mg2+ by using conventional cation exchange columns as the pre-column. The analyte anions were excellently separated by this method and, furthermore, “exclusive” distribution (single peak per one species of anion) was obtained. Real sample (underground water) was analyzed in duplicate using a conventional anion-exchange IC and this proposed method and identical results were obtained.

Poly(N,N?-dimethylacrylamide-co-acrylic acid): Synthesis, characterization, and application for the removal and separation of inorganic ions in aqueous solution

The synthesis of poly (N,N′-dimethylacrylamide-co-acrylic acd) under different feed molar ratios was carried out by radical polymerization. Both homopolymers were also synthesized to compare the metal ion binding abilities. All polymers were water-soluble and were characterized by FTIR, 1H-NMR, 13C-NMR, and TGA. The metal complexing properties for the metals Cu(II), Co(II), Ni(II), Cd(II), Zn(II), Pb(II), Hg(II), Cr(III), and Fe(III) in the aqueous phase were investigated using the liquid-phase polymer-based retention (LPR) method. The metal ion interactions with the hydrophilic polymer were determined as a function of pH and the filtration factor. According to the interaction pattern obtained, the metal ions form the most stable complexes with the copolymer poly(N,N′-dimethylacrylamide-co-acrylic acid) within the pH range 5–7. Hg(II) was not retained at all the pH ranges investigated. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67: 93–100, 1998

Poly(N,N′‐dimethylacrylamide‐co‐acrylic acid): Synthesis, characterization, and application for the removal and separation of inorganic ions in aqueous solution

Poly(N,N′‐dimethylacrylamide‐co‐acrylic acid): Synthesis, characterization, and application for the removal and separation of inorganic ions in aqueous solution

Bonded-phase capillaries and the separation of inorganic ions by high-voltage capillary electrophoresis

Both a C 1 and a C 18 saturated hydrocarbon have been bonded to 75-μm capillaries for high-voltage capillary electrophoresis separations. The performance of these bonded phases has been compared with unbonded capillaries under a variety of experimental conditions. The bonded phases were prepared by a flow-through procedure at room temperature, and the reproducibilities of the electroosmotic flow for the C 1 and C 18 capillaries were 6 and 3%, respectively. Both of the bonded phases reduced interactions between the silica surface and positively charged ions, but for larger hydrophobic ions sorption and peak tailing were observed on the C 18 phase. In the presence of sodium dodecylsulfate and sodium decanesulfonate it was possible to control the electroosmotic flow over a wide range. The separation of lanthanide metal ions is illustrated, and improved resolution and reduced surface interactions are shown for the bonded phases.

Microbore packed-column anion chromatography using a UV detector

A micro packed-column anion chromatograph with a UV detector has been constructed and the applicability of the system is demonstrated. A flexible fusedsilica capillary (0.19 mm I.D.) was used as a chromatographic tube and a surface-agglomerated and bonded low ion-exchange capacity anion-exchange resin, developed for ion chromatography, was packed into an ion-exchange column. Separations of inorganic ions, nucleobases, nucleotides and organic-acids were achieved using this system.

The use of the amphoteric ion-exchange resin retardion 11A8 for inorganic separations

The use of the “snake in a cage” amphoteric ion-exchange resin Retardion 11A8 for various separations of inorganic ions was investigated. Clean separations of Ga(III)In(III)Tl(III), Pt(II)Pd(II), and Na(I)Ni(II)Cu(II)Zn(II) mixtures have been achieved. In acidic media, in which the resin acts mainly as an anion exchanger, some residual activity of the acrylate polyanion seems to exist, resulting in significant changes in distribution coefficients in comparison with standard anion-exchange resins. In the case of elements that can exist as both cations and anions in solution ( e.g., Ni, Co, Cu and Zn), the amphoteric properties of Retardion 11A8 permit more specific isolation of certain elements from complex mixtures than would be possible with the use of monofunctional ion exchangers.

Separations of carbohydrates based on ion exclusion and gel permeation

A method is described for the fractionation of oligosaccharides by molecular size on columns of cation-exchange resin with water as the sole eluant. The same system allowed separation of inorganic ions and acidic carbohydrates from neutral components. The elution of amino acids and peptides is described, and the application to separation problems in carbohydrate chemistry is discussed.

Separation of inorganic ions in fused salts by means of chromatography and electrophoresis on glass fiber paper : III. Effect of water, oxygen and support on the migration of inorganic ions dissolved in the LiClKCl eutectic at 45°

The chromatographic and electrophoretic behaviour of different metal ions dissolved in LiClKCl eutectic was studied. It was found that: (a) Traces of water in the eutectic precipitate metal ions forming sparingly soluble oxides in fused alkali chlorides. (b) The ions examined did not react with the glass fiber paper employed as support. (c) When the ions to be examined are easily oxidized or give sparingly soluble oxides in molten chlorides the experiments must be performed in an inert gas atmosphere (water and oxygen free). The chromatographic and electrophoretic behaviour of some inorganic ions is reported and the electroendosmotic effect in fused chlorides, employing glass fiber paper as support, is disccused.

The separation of inorganic ions by electrophoresis on paper impregnated with ion exchangers

Factors influencing the movement of inorganic substances on ion exchange papers when subjected to an electric field were studied. Amberlite SA 2 paper and filter paper impregnated with zirconium phosphate were used. It is shown that various cases exist where electrophoresis on ion exchange papers presents advanteges over either electrophoresis on cellulose paper or chromatography on ion exchange paper. (P.C.H.)

Separation of inorganic ions in fused salts by electrophoresis on glass fiber paper

The possibility of separating various inorganic ions by means of electrophoresis in fused salis, employing glass fiber paper as the support, was investigated. Electrophoresis was carried out in a pyrex glass oven. It was found that some separations are possible. (M.C.G.)

A comprehensive bibliography of recent separations of inorganic ions by electromigration in paper

A comprehensive bibliography of recent separations of inorganic ions by electromigration in paper