• 대한화학회지
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• 제13권1호
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• pp.37-40
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• 1969

The separation and species of $MoO_4^{--}$ and $WO_4^{--}$ at the various PH value have been studied by the method of cation exchange chromatography. Elution curves of $MoO_4^{--}$ and $WO_4^{--}$ have been made with a 5 cm column of the resin, $Dowe{\times}50W{\times}12$(100-200 mesh), using solutions of various PH value as eluent. Complete separation of $MoO_4^{--}$ and $WO_4^{--}$ was obtained in each PH of 10% EtOH. According to the evaluation of peak position and number of peaks of elution curves, it is likely to exist cationic species of $MoO_4^{--}$.

• 자연과학논문집
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• 제5권1호
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• pp.77-86
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• 1992

양이온 교환반응에 의해 몬트모릴로나이트내의 금속 양이온을 긴 chain을 갖는 유기 양이온 tenside로 치환시킴으로써 물성이 다른 몬트모닐롤나이트의 층간화합물을 형성하게 된다. 이러한 층간화합물은 공업적으로 아주 광범위하게 이용되는가 하면, model-systems로서 물질의 거동을 밝혀내는 학문적 연구에 또한 많이 이용되기도 한다. 따라서 본 연구에서는 이러한 몬트모릴로나이트의 층간화합물을 형성하여 여러 상이한 조건하에서의 이들의 거동에 대하여 연구했다.

• Bulletin of the Korean Chemical Society
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• 제28권11호
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• pp.2075-2078
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• 2007

Oligomerization of isobutene has been investigated using a few solid acid catalysts in order to produce efficiently triisobutenes that are useful chemical feedstocks for heavy alkylates and neo-acids. Several reaction conditions such as space velocity and isobutene concentration are evaluated, and a few cation exchange resins with various acid capacities were compared in the reaction. High trimers selectivity and high conversion can be obtained over a catalyst containing high acid capacity at low space velocity and relatively low isobutene concentration. The stability of a catalyst for the reaction is high when the acid capacity of the catalyst is high (for example Amberlyst-35).

• 대한화학회지
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• 제8권2호
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• pp.62-64
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• 1964

The cation exchange chromatographic studies for the analysis of transition metals have been described. The quantitative separation of a mixture of Fe(Ⅲ), Cu(II), Zn(II), Ni(II), Cd(II), Co(II) and Mn(II) has been obtained by elution, through a 28cm column of the resin, Dowex 50 ${\times}$ 4 (100∼200 mesh), using 0.45 M $NaNO_3$+0.05 M Na-tartrate solution as eluent, starting with the eluent of pH 3.5, followed stepwise by pH 4.0 and 4.5. A comparison between the calculated and the observed peak positions in the elution curve has been shown. The relative stability constants for tartrate complexes of some transition metals have been calculated by using distribution ratios obtained in this separation procedure.

• 한국표면공학회지
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• 제26권6호
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• pp.334-340
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• 1993

The physico-chemical properties and characteristics after thermal treatment of natural zeolite from Kampo area were studied. The physico-chemical properties of natural zeolite were studied by investigating chemical composition, x-ray diffraction pattern(XRD), scanning electronic microscope(SEM), infrared spec-tra(IR), thermal analysis(TA), and cation exchange capacity(C.E.C.), and the characteristics of natural zeo-lite after thermal treatment from $400^{\circ}C$ to $900^{\circ}C$ were compared with the natural zeolite. This study showed that clinoptilolite was the predominant costituent in natural zeolite, and the natural zeolite contained a little amount of quartz and feldspar as impurities. Zeolite mineral was seen to develop slowly by the natural alternation of volcanic ash considering the almost amorphous crystal structure. The more temperature of ther-mal treatment increased, the more adsorption capacity decreased, considering the fact that the hydroxy peak diminished on infrared spectra, and that cation exchange capacity also decreased distinctly.

• Nuclear Engineering and Technology
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• 제53권3호
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• pp.894-900
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• 2021

This paper examines sorption of Pd(II) onto illite, MX-80 bentonite, and Queenston shale in Na-Ca-Cl solutions of varying ionic strength (IS) from 0.01 to 6.0 mol/L (M) and pH_c ranging from 3 to 9 under atmospheric conditions. A 2-site protolysis non-electrostatic surface complexation and cation exchange model was applied to the Pd sorption onto illite and MX-80 using PHREEQC, and the model results were compared to the experimental ones obtained in this work. Surface complexation and cation exchange constants were estimated for both illite and MX-80 through the optimization process to bring the predicted distribution coefficients from the model into alignment with the experimentally derived values. These optimized surface complexation constants were compared to existing linear free energy relationships (LFER).

• Bulletin of the Korean Chemical Society
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• 제6권4호
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• pp.225-228
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• 1985

The absorptions of Fe(Ⅲ), Tb(Ⅲ), Tl(Ⅰ), Ce(Ⅲ), Th(Ⅳ), and $UO_2^{2+}$ ions into the Dowex 50W-X2, 100-200 mesh resin were investigated by spectrophotometry to understand the abnormal strong absorption behavior of cations to cation exchange resins in concentrated HClO4. The distribution coefficients increase in the order : Tl(Ⅰ) < Fe(Ⅲ) < Tb(Ⅲ)∼Ce(Ⅲ) < $UO_2^{2+}$< Th(Ⅳ) and the order is interpreted in terms of the ratio of charge-to-ionic radius. The mole ratios of increment of $ClO_4^-$ ion absorption to metal ion absorption showed the same order as the distribution coefficients, which indicates that the electrostatic association between $ClO_4^-$ ion and metal ion plays a major role in the strong absorption.

• Mass Spectrometry Letters
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• 제15권2호
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• pp.107-119
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• 2024

We aimed to develop a suitable quantification method for detecting asparagine deamidation and aspartic acid isomerization in peptide mapping using LC-MS. Our assessment of its validity and suitability involved comparing its quantitative findings with those obtained from cation-exchange chromatography and capillary electrophoresis methods. By subjecting trastuzumab to rigorous conditions to induce these modifications, we validated the efficacy of this new analytical method in peptide mapping via LC-MS, evaluating both qualitative and quantitative aspects of asparagine deamidation and aspartic acid isomerization. Our investigation underscored the significance of enzyme selection and the presence of miss-cleaved or non-specific peptides in achieving accurate quantitative results. The experimental results demonstrated a strong correlation with results from cation-exchange chromatography and capillary electrophoresis analyses, confirming the reliability of the LC-MS based peptide mapping approach.

• 한국세라믹학회지
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• 제22권4호
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• pp.3-8
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• 1985

The layer charge densities and interlayer C. E. C(cation exchange capacity) of ten mica-type aluminosilicates from Yong-il Pohang-prefacture were determined by n-alkylammonium method which is based on the mo-nolayer-doubelelayer structural transition of ni-alkylammonium ion in interlayer space of the layered silcates. The upper and lower limits of layer charge and interlyer C, E, C estimated were about 0.25~0.36 eq/(Si, $Al)_4$ O10 and 69~99meq/100g, respectively.

• Bulletin of the Korean Chemical Society
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• 제3권2호
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• pp.66-70
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• 1982

The question of the bicyclohomoaromatic stabilization and destabilization is examined. The chemistry of bicyclo(3.2.1)octa-3,6-dienide anion has been studied on order to test these concepts. The bicyclooctadienide anion is shown to be stable delocalized ion which undergoes a facile proton-deuterium exchange reaction. The solvolysis of bicyclo(3.2.1)octa-3,6-dienyl p-nitrobenzoate is much slower than the monoene analog. We have made direct observation of the bicyclooctadienyl and octenyl cations by $^{19}F$-nmr spectroscopy, and were able to demonstrate that the bicyclooctadienyl cation was bishomoantiaromatic.