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Abstract  

The sorption capacities of hydrous SiO2 and ZrO2 for the Zn(ammine) ion have been observed to increase on irradiation with γ-rays, by ca. 4.1 and 3.8%, respectively. The rates of sorption increase differently in the irradiated exchangers, depending upon their characteristic natures; e. g. when the external concentration of the Zn(ammine) solution is 0.2M, the increase in the F value due to irradiation is more striking in the case of SiO2 than for ZrO2. On the other hand, at a lower external concentration of the Zn(ammine) solution (0.01M), the increase in the F value, particularly during the first five minutes, is more significant for ZrO2.

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Certain micro-chemical separations using hydrous ferric oxide as a selective sorbent

I. Micro-analysis of binary mixtures of zinc with copper and nickel

Journal of Radioanalytical and Nuclear Chemistry
Authors: Brij Bhushan and K. Kar

Abstract  

Separation of zinc from copper and nickel by the selective sorption of Zn(en)3 2+ on hydrous ferric oxide is reported. The details of the batch procedure and the tests of the separation efficiency are described.

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Certain micro-chemical separations using hydrous ferric oxide as a selective sorbent

II. Separation and determinations of small amounts of cadmium from copper and from nickel

Journal of Radioanalytical and Nuclear Chemistry
Authors: Brij Bhushan and K. Kar

Abstract  

Traces of cadmium from relatively high amounts of nickel and copper can be separated by the selective sorption of the cadmium ethylenediamine complex on hydrous ferric oxide. A batch chromatographic technique has been elaborated on this basis.

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Abstract  

The equilibirum sorption capacity of hydrous ferric oxide and ferric phosphate has been observed to increase on irradiation with γ-rays by 5.2 and 6.6%, respectively. The rate of sorption increases differently in the irradiated exchanger materials depending upon their characteristics nature; e.g., when the concentration of the Zn(ammine) solution is 0.10M, increase in the F-values, caused by irradiation is significantly more striking in the case of hydrous ferric oxide than in ferric phosphate. On the other hand, at lower external concentration of the Zn(ammine) ion (0.01M), the increase in F-values is more significant in the case of ferric phosphate.

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A simple, rapid, quantitative, and validated high-performance thin-layer chromatographic (HPTLC) method has been developed for the simultaneous estimation of quercetin (QU), rutin (RU), and gallic acid (GA) in the methanolic extract of Amaranthus tricolor L. aerial parts. Densitometric analysis of QU, RU, and GA were carried out in the absorbance mode at 254 nm. The method gave spot at R F 0.49, 0.14, and 0.28 corresponding to quercetin, rutin, and gallic acid, respectively. The limit of detection (22.31, 14.12, and 16.24 ng per spot) and limit of quantification (67.80, 55.32, and 52.54 ng per spot), respectively, were confirmed with the mobile phase toluene–ethyl acetate–formic acid in a ratio of 7:5:1 (v/v). Linear regression analysis data for the calibration plot for QU, RU, and GA showed a good linear relationship with a correlation coefficient r > 0.9955 in the concentration range of 200–800 ng per spot, 200–500 ng per spot, and 200–600 ng per spot, respectively. The method was validated for linearity, accuracy, precision, detection, and quantification limits, specificity, and robustness as per the International Conference on Harmonization (ICH) guidelines. The proposed validated high-performance thin-layer chromatographic method provides a novel approach for the quality control and standardization of A. tricolor L.

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Abstract  

Kinetics of the exchange reaction of cadmium(II)-ammine complex ion using radio-active isotope115Cd in the same chemical form in hydrous oxides of zirconium(IV), silicon(IV) and tin(IV) has been studied. It has been found that the major contribution in the overall exchange process is from the surface of the exchanger particles. It has also been found that the rate of exchange follows the order: hydrous ZrO2>hydrous SnO2>hydrous SiO2

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Biodegradable polymers

Part VI. Biodegradable plastics of soy protein isolate modified with thiourea

Journal of Thermal Analysis and Calorimetry
Authors: P. Nanda, K. Rao, R. Kar, and P. Nayak

Abstract  

Potential alternative to petrochemical polymers, soy protein isolate (SPI), a plentily available, natural biopolymer is chemically modified with thiourea at 2.5, 5, 7.5, 10, 15 and 20 mass/mass% for better processing of plastic as a raw material. From the FTIR studies, it has been ascertained that there is no bonding reaction between SPI and thiourea and it acts as a modifier only. Thermogravimetric analysis of the modified material has been followed using a computer analysis method, LOTUS package, developed by us for assigning the degradation mechanism. A number of equations have been used to evaluate the kinetic parameters. The mechanism of degradation of the biopolymer is explained on the basis of the kinetic analysis.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: Sharayu Kasar, Sumit Kumar, Aishwarya Kar, K. Krishnan, N. Kulkarni, and B. Tomar

Abstract  

Sorption of Eu(III), an analogue of trivalent actinides (Am, Cm), by amorphous titania as well as different crystalline phases of titania, namely anatase and rutile, have been studied as a function of pH, using 154Eu (half life = 8.8 yrs, Eγ = 123,247 keV) as a radiotracer. The objective of this study was to investigate the effect of the crystalline phase of the titania on their sorption behaviour towards the metal ion. Amorphous titania was prepared by organic route and was converted into anatase and rutile by heating at elevated temperatures based on the differential thermal analysis studies. Eu(III) sorption by all forms of titania rises sharply with the pH of the suspension, with the sorption edge shifting to higher value in the order; amorphous < anatase < rutile. However, the normalization of the sorption data to the surface area of the sorbents resulted in the overlapping of the sorption curves for amorphous and anatase phases, with the data being higher for rutle in the lower pH region, indicating the effect of the crystal phase on sorption behaviour of Eu(III).

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