Search Results

You are looking at 21 - 30 of 47 items for

  • Author or Editor: N. Kumar x
  • Refine by Access: All Content x
Clear All Modify Search

Summary

A simple, selective, and stability-indicating reverse phase liquid chromatographic method has been developed and validated for the simultaneous determination of impurities and forced degradation products of quetiapine fumarate. The chromatographic separation was achieved on Inertsil-3 C8, 150 mm × 4.6 mm, 5 μm column at 35°C with UV detection at 217 nm using gradient mobile phase at a flow rate of 1.0 mL/min. Mobile phase A contains a mixture of 0.01 M di-potassium hydrogen orthophosphate (pH 6.8) and acetonitrile in the ratio of 80:20 (v/v), respectively, and mobile phase B contains a mixture of 0.01 M di-potassium hydrogen orthophosphate (pH 6.8) and acetonitrile in the ratio of 20:80 (v/v), respectively. The drug product was subjected to the stress conditions of oxidative, hydrolysis (acid and base), hydrolytic, thermal, and photolytic degradation. Quetiapine fumarate was found to degrade significantly in acid, base, and oxidative stress conditions. The degradation products were well resolved from main peak and its impurities. The mass balance was found to be in the range of 96.6–102.2% in all the stressed conditions, thus proved the stability-indicating power of the method. The developed method was validated as per ICH guidelines with respect to specificity, linearity, limit of detection and quantification, accuracy, precision, and robustness.

Full access

Abstract  

This paper describes Jet Entrainment Technique (JET) developed at Bhabha Atomic Research Centre (BARC) for the preparation of small microspheres of UO2 in the size range of 100±20 μm diameter. The UO2 microspheres were prepared by Internal Gelation Process (IGP) using selected feed solution compositions. Equipment development and the optimized process operations for obtaining more than 90% of high density UO2 microspheres in the desired size range are described.

Restricted access

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.

Restricted access

A Holstein-Friesian cow aged 6 years aborted twice at 3-4 months of gestation. On rectal palpation a growth was palpable in the apex of one uterine horn. The growth was removed by right flank laparotomy under sedation and paravertebral nerve block. The growth was diagnosed to be a fibroma. The cow conceived and calved normally after the operation.

Restricted access

Abstract

12-Molybdophosphoric acid (MPA) supported on V2O5 dispersed γ-Al2O3 catalysts with different loadings were prepared and characterized by BET surface area, X-ray diffraction, FT-infrared, laser Raman, X-ray photoelectron spectroscopy and temperature programmed reduction techniques. The catalytic activities were evaluated for the aerobic oxidation of benzyl alcohol. The conversion of benzyl alcohol increased with the amount of MPA content and the catalyst with 15 wt% of MPA showed highest activity. The synergistic effect of V2O5 and MPA was observed for the oxidation of benzyl alcohol compared to MPA on alumina without V2O5. The XPS results suggest the participation of both Mo and V in the reaction as the used catalysts showed the reduced oxidation states of both Mo and V. The high selectivity of the catalysts is due to the presence of V2O5, which induces the redox nature to the catalyst and also preventing the decomposition of MPA on Al2O3.

Restricted access
Journal of Radioanalytical and Nuclear Chemistry
Authors: M. Alrakabi, G. Singh, A. Bhalla, S. Kumar, S. Kumar, A. Srivastava, B. Rai, N. Singh, J. Shahi, and D. Mehta

Abstract  

The elemental concentration of uranium in the samples collected from the ground water and the canal water in the Bathinda district of Punjab state, India, have been investigated using X-ray fluorescence technique. The residues obtained after drying the water samples were analysed using the energy dispersive X-ray fluorescence spectrometer consisting of Mo-anode X-ray tube equipped with selective absorbers as an excitation source and an Si(Li) detector. The uranium concentration values in significant fraction of the shallow ground water samples from the hand pumps is found to be above the permissible level of 15 ppb recommended by World Health Organisation for the drinking water, and its values in the canal water samples are below 5 ppb. To investigate the flyash from the coal-fired thermal power plants as a possible source of ground water contamination, the water samples collected from the surroundings of the power plants and the flyash samples were also analyzed. The results rule out flyash as a source of uranium contamination. Agrochemical processes occurring in the calcareous soils in the region are the favoured potential source of uranium contamination of the ground water.

Restricted access

Nitrogen use efficiency, more specifically physiological nitrogen use efficiency depends primarily on management of N, one of the major essential nutrients. It is required in increased agricultural production and may possibly cause soil toxicity if fed in excess. Rate of N fertilizer application in fertile agricultural field and improved productivity in sterile soils require the improvement of NUE. A field experiment was therefore conducted to evaluate the effect of different N levels (N0, N50, N100 and N200) on rice genotypes. Vegetative plant growth was found to be reduced under N0 while improved at N200 level. Among the genotypes, highest PNUE (34.94) and correspondingly higher yield (7.15 ton ha−1) was observed for Krishna Hamsa. The other traits viz. plant height, no. of productive tillers and LAI exhibited higher values for Krishna Hamsa as well. Hence these can be utilized as physiological markers for the selection of rice genotypes efficient in N use.

Restricted access

Abstract  

Partitioning of minor alpha-emitting actinides, especially U, Pu and Am from medium active alkaline waste is possible from intermediate level liquid wastes (ILLW) produced during spent fuel reprocessing following Purex process. This paper deals with the efficient removal of alpha-activity from ILLW by solvent extraction process. Counter current batch extraction with O/A ratio 2:1 as well as multistage mixer settler has demonstrated that most of the alpha-activity was removed from the alkaline effluents using 20% Versatic-10 (V-10) in dodecane after giving 3 to 4 contacts, thus converting alkaline waste as non-alpha waste. Under the optimum conditions (pH 9.0-9.5 and VA-10), both Pu(IV) and Am(III) are highly extractable whereas U(VI) is relatively poorly extracted. To assess the applicability of this process for regular treatment of the waste, a feasibility study on pilot plant scale using six stage mixer settler was operated to treat the ILLW. The results indicated that almost >99.90% alpha-emitting actinides are removed. Dilute nitric acid (0.5M HNO3) served as the most efficient strippant for all these actinides. This facilitate an easy regeneration of the extractant which can be recycled. This method is useful in obtaining alpha-free wastes and had positive impact on ease and safety aspects during subsequent waste treatment and long term storage.

Restricted access
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).

Restricted access
Journal of Radioanalytical and Nuclear Chemistry
Authors: R. Kumar, N. Sivaraman, A. Thiruvenkadasamy, C.R. Venkata Subramani, and P.R. Vasudeva Rao

Abstract  

Carrier-free 22Na was separated from bulk quantities of magnesium by both ion exchange and extraction chromatographic techniques. An extraction chromatographic procedure based on di-(2-ethylhexyl) phosphoric acid (HDEHP) coated on to an inert support (Amberlite XAD-7) was developed for the first time for separation of sodium from magnesium. The sorption behavior for sodium and magnesium was studied as a function of percentage of HDEHP loaded on to the inert support as well as pH of aqueous phase. These data were used to arrive at the optimum conditions of separation. In addition, carrier free 22Na was also separated from magnesium using ion exchange chromatographic technique.

Restricted access