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  • Author or Editor: Kumar Raj x
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Abstract  

57Fe Mössbauer spectroscopy has been employed to characterize the chemical composition of iron aerosols collected from three distinct groups of sites representing remote, urban and industrially active areas. The Mössbauer spectra clearly show this environmental difference. The fact that the spectra of the samples collected from the remote areas are quite similar to those of clay minerals corroborates the view that iron aerosols are soil derived. Similarly the predominant presence of -Fe2O3 and Fe3O4 in the close vicinity of industrial activities suggests that the Mössbauer spectroscopy can help identify the anthropogenic processes against the natural ones.

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Abstract  

Cerium(IV) molybdate, prepared under the optimum conditions of concentration, acidity etc., shows exchange capacity of 0.96 meq per g of exchanger. The sorption of a large number of metal ions has been investigated and the compound shows promising behaviour as cation exchanger. Numerous separations of analytical and radiochemical interest have been performed on the columns of this exchanger with great efficiency.

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The sorption of univalent, bivalent and trivalent ions has been studied on chromium ferrocyanide gel. The studies reveal a high sorption capacity for Cs+, Tl+, Ag+, Cu2+, Zn2+, Cd2+, Fe3+ and Th4+. The sorption of monovalent cations show purely ion-exchange mechanism while the uptake of bivalent and trivalent cations is non-equivalent in nature. Single elution of Rb+, Cs+ and Tl+ has been performed from the columns of this exchanger and the recovery is almost complete in all the cases. Cu2+ and Ag+ get completely adsorbed on the gel column and their elution is not possible probably due to the formation of some new solid phases. Depending on the Kd values of the metal ions, a large number of separations of radiochemical as well as analytical importance can be performed on the columns of this exchanger material.

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The tendency of selenium to interact with heavy metals in presence of naturally occurring species has been exploited for the development of green bioremediation of toxic metals from soil using Artificial Neural Network (ANN) modeling. The cross validation of the data for the reduction in uptake of Hg(II) ions in the plant R. sativus grown in soil and sand culture in presence of selenium has been used for ANN modeling. ANN model based on the combination of back propagation and principal component analysis was able to predict the reduction in Hg uptake with a sigmoid axon transfer function. The data of fifty laboratory experimental sets were used for structuring single layer ANN model. Series of experiments resulted into the performance evaluation based on considering 20% data for testing and 20% data for cross validation at 1,500 Epoch with 0.70 momentums The Levenberg–Marquardt algorithm (LMA) was found as the best of BP algorithms with a minimum mean squared error at the eighth place of the decimal for training (MSE) and cross validation.

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Summary

Background: The fruits of Benincasa hispida (Thunb.) Cogniaux, a ‘rasayana’ in ‘Ayurveda’, are enriched with several secondary metabolites, and rutin is one of them. Fruits are used for their anabolic, brain tonic, carminative, diuretic, memory enhancer, refrigerant, and vitalizer properties. Objective: In view of the fact that herbal medicines and/or products are facing challenges towards global acceptance due to the lack of universally accepted standardization method (s), the aim of the current investigation was to develop and validate a high-performance thin-layer chromatography (HPTLC)-densitometry method for the quantification of rutin in the hydroalcoholic extracts of the fruit pulp of B. hispida (HABH). Materials and methods: The separation was achieved in a solvent system consisting of ethyl acetate-formic acid-acetic acid-water at a ratio of 7.2:0.7:0.7:1.4 by volume on a TLC aluminum plate pre-coated with silica gel 60 F254. Quantifications were performed by densitometric scanning under a deuterium lamp at a wavelength of 268 nm in the absorbance mode. The precision, accuracy, and reproducibility of the HPTLC method were validated by the International Conference on Harmonization (ICH) guidelines. Results: The mobile phase employed for HPTLC/TLC resulted in good separation for rutin (R F = 0.357). The limit of detection and limit of quantification of the analysis were found to be 0.1 and 0.3 µg per band, respectively. The rutin concentration in the HABH was found to be 178.28 ± 3.62 µg in 10 mg of the extract. Conclusion: The method developed here is simple, fast, reliable, and sensitive and can be implemented in the analysis and routine quality control of B. hispida formulations containing rutin.

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Background: Ayurvedic medicines show great promise due to their holistic approach in the treatment of diseases. However, proper standardization is necessary for their integration into mainstream medicine. One such well-known Ayurvedic trailing herb is Benincasa hispida (Thunb.) Cogn. Its fruit contains numerous secondary metabolites, including quercetin, and is used to treat urinary calculi, blood disease, insanity, epilepsy, jaundice, dyspepsia, fever, and menstrual disorders. Objective: The current investigation was undertaken to develop and validate a rapid, sensitive, and reproducible method for quantifying quercetin in the hydroalcoholic extract of B. hispida fruit pulp (HABH). Materials and methods: The pre-coated thin-layer chromatography (TLC) aluminum plates with silica gel 60 F254 were used with solvent system comprising toluene-ethyl acetate-formic acid (5:4:0.2, V/V). Determination and quantification were performed by densitometric scanning using a deuterium lamp in the absorbance mode at 262 nm. The validation of precision, accuracy, and reproducibility of the developed high-performance thin-layer chromatographic (HPTLC) method were done as per the International Conference on Harmonization (ICH) guidelines. Results: The mobile phase used for the development of HPTLC/TLC plate yields a distinct band for quercetin (RF = 0.392). The limit of detection and limit of quantification for the method were found to be 20 and 60 ng per band, respectively. The quantified quercetin content was found to be 193.77 ± 2.86 µg in 10 mg of HABH, i.e., 1.94% w/w of HABH. Conclusion: This HPTLC method can be successfully employed for the standardization and quantitative analysis of quercetin in formulation containing B. hispida fruit pulp and it will be helpful in the quality control/assurance of such formulations.

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Abstract  

Ion-exchange papers were prepared by impregnating chromatographic Whatman No. 3 paper with pyridinium tungstoarsenate exchanger. The composition of the material loaded on the paper shows that the compound has the formula (C5H5NH)3 W1 2AsO4 0·Rf values of 30 metal ions were determined on these ion-exchange papers by developing with ascending technique in solvents containing mixtures of n-propanol and hydrochloric or nitric acid. Several binary, ternary and some quaternary separations were also achieved on these papers. Studies were also made on plain papers for comparison.

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Abstract  

Drinking water samples were collected from four different districts, namely Bhatinda, Mansa, Faridkot and Firozpur, of Punjab for ascertaining the U(nat.) concentrations. All samples were preserved, processed and analyzed by laser fluorimetry (LF). To ensure accuracy of the data obtained by LF, few samples (10 nos) from each district were analyzed by alpha spectrometry as well as by fission track analysis (FTA) technique. For FTA technique few μl of water sample was transferred to polythene tube, lexan detector was immersed in it and the other end of the tube was also heat-sealed. Two samples and one uranium standard were irradiated in DHRUVA reactor. Irradiated detectors were chemically etched and tracks counted using an optical microscope. Uranium concentrations in samples ranged from 3.2 to 60.5 ppb and were comparable with those observed by LF.

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Abstract  

Diffusion of sodium in Mn and Ti bearing sodium borosilicate glass used for the immobilization of the high level waste at the Waste Immobilization Plant, Tarapur has been studied by heterogeneous isotopic exchange using 24Na as the radiotracer for sodium. The temperature dependence of the self-diffusion coefficient of sodium in the glass was found to follow Arrhenius equation below the glass transition temperature.

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