The uptake of 22 cations at tracer concentrations has been studied over hydrous tin dioxide exchanger material. A granular variety of tin dioxide was prepared from the reaction of tin(IV) chloride with NaOH solution, and the formula of the material was ascertained to be SnO2·1.7 H2O. Radiochemical separation of carrier-free234Th from238U and113mIn from113Sn was achieved over a tin dioxide column. The separated products were of high radionuclidic purity. The overall separation procedures are very simple and quick with quantitative yield.
A radiochemical solvent extraction method for the determination of iron(III) employing the chelating extractant malonic anilide (MA), synthesized in our laboratory, has been described. Effects of different parameters on the extraction of iron(III) from 2M hydrochloric acid into a mixed organic solvent (methyl isobutyl ketone (TIBK) and diethyl ether) have been studied in detail. The method was applied for the estimation of iron content in several fruits using the principle of substoiciometric isotope dilution analysis.
Authors:B. Mohanta, A. Chakraborty, M. Sudarshan, R. Dutta, and M. Baruah
Several parts of plants are used in herbal and Ayurvedic medicines of India. The different elemental constituents at trace levels of these plant parts play an effective role in the medicines prepared. Elemental composition of different parts (root, bark, leaf, seed) of some medicinal plants of North Eastern India has been determined by using proton induced X-ray emission (PIXE). A total of 14 elements, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Br, Rb, Sr, Y, Zr and Pb have been measured. Their concentrations were found to vary in different samples. Medicinal properties of these plant samples and their elemental distribution have been correlated.
Authors:S. Dutta, P. Mohapatra, V. Manchanda, and A. Das
The work describes a procedure of preconcentration and separation of trace amounts of Pd(II) by solid phase extraction of
the metal ion by dithiooxamide groups incorporated into a matrix of polystyrene-divinylbenzene whereas the determination of
palladium has been carried out by radiotracer technique using 109Pd (T1/2 = 13.43 hr, Eγ = 311, 647 keV). The experiments were carried out using both batch method and column operation. Parameters such as the amount
of resin, effect of pH, equilibration rate, sorption and desorption of metal ions have been studied. The maximum sorption
capacity for palladium was found to be 0.10 mmol·g−1 at pH 6.0. The method is rapid, has a good accuracy and can be used routinely.
Authors:R. Maharia, R. Dutta, R. Acharya, and A. Reddy
Three commonly used medicinal plants, e.g., Adhatoda vasica, Cassia fistula, and Withania somnifera grown in two contrasting environmental conditions, namely from copper mining site and from control site corresponding to
soil not contaminated with Cu, to understand correlations between high Cu bioaccumulation in medicinal plants on their antioxidant
activities. Concentrations of some essential metals, e.g., Cr, Mn, Fe, Cu, Zn, and Se in the leaves of these plants were measured
by instrumental neutron activation analysis. The Cu levels in the samples from mining site were in the range of 32.6 to 57.2 mg/kg,
which were 5–7 folds higher than the control samples, while Cr levels were about 2-folds higher in the mining site. Speciation
studies of Cr revealed negligible content of toxic hexavalent Cr. Antioxidant assay of these plants from both the sampling
sites, measured as total phenolic content, total flavonoid content, 2,2′-diphenyl-1-picrylhydrazyl, free radical scavenging
ability, and chelating ability with ferrous ions exhibited maximum activity for A. vasica, while that of W. somnifera was minimum. However, the variations in the antioxidant activities for each medicinal plant species from mining site and
control site did not reveal significant differences.
Authors:R. Dutta, R. Acharya, V. Chakravortty, A. Nair, A. Reddy, S. Chintalapudi, and S. Manohar
Three ferromanganese crusts from different locations of the Indian Ocean were analysed by neutron activation analysis using
thek0 method (k0 NAA method) for studying the distribution of some trace elements along with Fe and Mn. Another crust from the Lau basin of
the Pacific Ocean was investigated for comparison of the influence of different oceanic conditions on the trace element distributions
in ferromanganese crusts. Variation in Co concentration along with the Mn/Fe ratio were discussed in terms of the hydrogenous/hydrothermal
nature of the crusts. The normalised REE content was used to identify possible anomalies. The observed Ce anomaly is discussed
in the light of the depositional environment. The precision and accuracy of the method were confirmed by measuring the elemental
concentrations in a USGS nodule standard NOD A-1.
Authors:A. Dutta, P. Gope, S. Banik, Md. Rahman, S. Makhnoon, M. Siddiquee, and Y. Kabir
Milled rice from nine aromatic cultivars was evaluated for physicochemical, cooking, and antioxidant properties. Physical parameters measured were milling outrun, head rice yield (HRY), and appearance (size and shape). Cooking time, water uptake ratio and elongation ratio were determined to study their cooking quality. Chemical parameters included were amylose content (AC), protein content (PC), gel consistency (GC) and alkali spreading value (ASV). Total phenolic content (TPC) was measured using the Folin-Ciocalteu method, while ferric reducing antioxidant power (FRAP), total antioxidant capacity (TAC), and 1,1-diphenylpicrylhydrazyl (DPPH) radical scavenging activity were used to study their antioxidant activity. This study revealed all rice cultivars, except Basmoti-370 and Gopalbhog, showed HRY. Besides, all rice cultivars displayed high protein content. Significant variations (P<0.05) were found in TPC and the antioxidant activities of the rice cultivars. The correlation coefficient between the TPC and the antioxidant activities was strong and statistically significant (P<0.05).
Authors:S. Dutta, A. Kundu, M. R. Chakraborty, S. Ojha, J. Chakrabarti, and N. C. Chatterjee
Siderophores are low molecular weight
(<1000 D) iron chelating compounds produced by microorganisms. Production of
siderophore is a device of antagonism as by virtue of the capacity of
siderophore production, a microorganism competes for Fe (III) with the others.
Production of siderophores by 9 different soil fungi and wood-decay fungi was
studied following CAS - assay and CAS - agar plate assay. Optimization for the production of
siderophores was done by varying the levels of pH and Fe (III) concentrations
in the low nutrient medium. All the test fungi could produce siderophores,
though the degree of production recorded to be very low both in Botryodiplodia
theobromae and in Fusarium spp. On the other hand, all the species of
Trichoderma showed their excellency in siderophore production. The optimum pH
for production of siderophores remained at neutral pH level though the range
varied from pH 6.0-8.0. The optimum range of the
concentration of Fe (III) required for siderophore production was recorded to
be 1.5-21.0 µM. However, the stress condition of
iron might be a decisive factor for siderophore production.