57. Ion-exchange studies of phosphates. Part I. Ion-exchange sorption and pH-titration methods for detection of complex formation

Cs-type layered manganese oxide with a novel hexagonal-like morphology (Cs–BirMO) was prepared by a solid-state reaction procedure. The Cs+ extraction and alkali–metal ion insertion reactions were investigated by chemical analyses, x-ray analyses, scanning electron microscopy observation, Fourier transform-infrared spectroscopy, thermogravimetric differential thermal analyses, pH titration, and distribution coefficient (Kd) measurements. A considerable percentage (88%) of Cs+ ions in the interlayer sites were topotactically extracted by acid treatment, accompanied by a slight change of the lattice parameters. Alkali–metal ions could be inserted into the interlayer of the acid-treated sample (H–BirMO), mainly by an ion-exchange mechanism. The pH titration curve of the H–BirMO sample showed a simple monobasic acid toward Li+, Rb+, and Cs+ ions, and dibasic acid behavior toward Na+ and K+ ions. The order of the apparent capacity was K+ > Li+ ≈ Na+ ≈ Rb+ ≈ Cs+ at pH < 6. The Kd study showed the selectivity sequence of K+ > Rb+ > Na+ > Li+ for alkali–metal ions at the range of pH <5; H–BirMO sample showed markedly high selectivity for the adsorption of K+ ions. Preliminary investigations of the electrochemical properties of the Li+-inserted sample Li–BirMO(1M, 6d) showed that the obtained samples had a relatively high discharge capacity of 115 mAh g−1 and excellent layered stability.

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The effect of complex formation on the sorption and transport of mercury(II) ions in ion-exchange membranes

Petroleum Chemistry ◽

10.1134/s0965544114080040 ◽

2014 ◽

Vol 54 (8) ◽

pp. 625-630 ◽

Cited By ~ 1

Author(s):

A. V. Dyukov ◽

S. V. Shishkina ◽

E. A. Zhelonkina ◽

B. A. Ananchenko

Keyword(s):

Complex Formation ◽

Ion Exchange ◽

Ion Exchange Membranes

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Preconcentration and Separation of Cr(III) and Cr(VI) from Aqueous Solutions by Complex Formation-ion Exchange

Studies in Environmental Science - Chemistry for Protection of The Environment, Proceedings of an International Conference ◽

10.1016/s0166-1116(08)71244-5 ◽

1984 ◽

pp. 381-385 ◽

Cited By ~ 3

Author(s):

C. Sarzanini ◽

E. Marengo ◽

M.C. Gennaro ◽

C. Baiocchi ◽

E. Mentasti

Keyword(s):

Complex Formation ◽

Ion Exchange ◽

Aqueous Solutions

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Preparation and characterization of taste masked valsartan by ion-exchange resin approach

Al Mustansiriyah Journal of Pharmaceutical Sciences ◽

10.32947/ajps.18.01.0358 ◽

2018 ◽

pp. 11-25

Keyword(s):

Complex Formation ◽

Ion Exchange ◽

Bitter Taste ◽

Exchange Resin ◽

Mixing Time ◽

Spectroscopic Method ◽

Ion Exchange Resin ◽

Drug Formulation ◽

Taste Masking ◽

Scanning Calorimetry

The bitter taste is one of the most important drug formulation problems. The unpleasant taste leads to noncompliance, which consequently decreases the therapeutic efficacy of the drug. Therefore, masking of bitter taste is very important in drug formulation. In this study an antihypertensive drug, valsartan, which is a weak acid with bitter taste, was used as a model drug to mask its taste with dowex2 (weak base anion exchange resin). The taste masking of a drug using ion exchange resin basically depends on the complex formation between the drug and a specific type of resin. Complex formation under various preparation conditions including; the ratio of drug to resin, mixing time, the pH of the processing medium and the concentration of valsartan was investigated in this study. Optimum conditions for complex formation and maximum drug load were obtained at a drug-resin ratio 1:8, mixing time 4 hours, pH 6.8, temperature 50º C and drug concentration 0.02% w/v. The drug resin ate complex was evaluated for the drug content, taste, drug release and molecular properties. The resinate formation was confirmed using different analytical techniques like thermal analysis using differential scanning calorimetry (DSC), spectroscopic method like Fourier transform infrared spectroscopy (FTIR) and by X-ray powder diffraction analysis (XRPD).

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Stability Constants of Metal Ion Complexes of Cyclopentadienyltris(diethylphosphito-P)cobaltate(1-), [(C5H5)CO{P(O)(OC2H5 )2 }3 ]-, an Oxygen Tripod Ligand

Zeitschrift für Naturforschung B ◽

10.1515/znb-1981-0810 ◽

1981 ◽

Vol 36 (8) ◽

pp. 949-951 ◽

Cited By ~ 17

Author(s):

Giorgio Anderegg ◽

Wolfgang Kläui

Keyword(s):

Complex Formation ◽

Transition Metal Complexes ◽

Metal Ion ◽

Sodium Complex ◽

Ph Titration ◽

Metal Ion Complexes ◽

Calorimetric Measurements ◽

Tetramethylammonium Chloride ◽

Sodium Complexes ◽

The Stability

AbstractThe formation of metal ion complexes ML(n-1)+ and ML2(n-2)+ of the oxygen tripod ligand L- = cyclopentadienyltris(diethylphosphito-P)cobaltate(l-) with metal ions Mn+ = Li+, Na+ , K+ , Mg2+ , Ca2+ , Sr2+ , Ba2+ , Mn2+ , Co2+ , Ni2+ , Cu2+ , Zn2+ ,Cd2+ , Hg2+ , Pb2+ , Ag+ ,and La3+ has been studied by pH titration at 25 °C in 95/5 methanol/water solutions kept at an ionic strength of 0.1 by means of tetramethylammonium chloride. The stability of the alkali metal ion complexes increases with decreasing metal ion radii. The sodium complex NaL is more stable than the known crown ether sodium complexes. The K1 values of the transition metal complexes ML+ are ≈ 109 [1/mol]. For H+ , Na+, Mg2+ , and La3+ the enthalpies and entropies of complex formation have been determined by calorimetric measurements. The results are comparable to those of the tripolyphosphate anion. The complex formation is slightly endothermic and the stability of the complexes arises from a large positive ⊿S of reaction.

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Preparation and characterization of taste masked valsartan by ion-exchange resin approach

Al Mustansiriyah Journal of Pharmaceutical Sciences ◽

10.32947/358 ◽

2018 ◽

Vol 18 (1) ◽

pp. 11-25

Keyword(s):

Complex Formation ◽

Ion Exchange ◽

Bitter Taste ◽

Exchange Resin ◽

Mixing Time ◽

Spectroscopic Method ◽

Ion Exchange Resin ◽

Drug Formulation ◽

Taste Masking ◽

Scanning Calorimetry

The bitter taste is one of the most important drug formulation problems. The unpleasant taste leads to noncompliance, which consequently decreases the therapeutic efficacy of the drug. Therefore, masking of bitter taste is very important in drug formulation. In this study an antihypertensive drug, valsartan, which is a weak acid with bitter taste, was used as a model drug to mask its taste with dowex2 (weak base anion exchange resin). The taste masking of a drug using ion exchange resin basically depends on the complex formation between the drug and a specific type of resin. Complex formation under various preparation conditions including; the ratio of drug to resin, mixing time, the pH of the processing medium and the concentration of valsartan was investigated in this study. Optimum conditions for complex formation and maximum drug load were obtained at a drug-resin ratio 1:8, mixing time 4 hours, pH 6.8, temperature 50º C and drug concentration 0.02% w/v. The drug resin ate complex was evaluated for the drug content, taste, drug release and molecular properties. The resinate formation was confirmed using different analytical techniques like thermal analysis using differential scanning calorimetry (DSC), spectroscopic method like Fourier transform infrared spectroscopy (FTIR) and by X-ray powder diffraction analysis (XRPD).

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