Authors:T. Balaji, R. Acharya, A. Nair, A. Reddy, K. Rao, G. Naidu, and S. Manohar
Elemental concentrations of a few medicinal leaves are determined by instrumental neutron activation analysis using the single comparator (k0) method. Data obtained for neem leaves, collected from two different places, have been used to see the effect of soil condition. The applicability of the method particularly for the simultaneous determination of Ca, Mg, V and Al in biological matrices has been evaluated in terms of the detection limit, precision and accuracy. The method was validated by analysing the NIST Standard Reference Material (SRM-1571) and it was found that the elemental concentrations measured in SRM-1571 are within ±10% of the reported values.
Authors:Munendra Singh, Alok Srivastava, Amol Shinde, R. Acharya, A. Reddy, and I. Singh
In northern part of Indian sub-continent, As related environmental and health issues receive attention from all over the world.
Forty-eight sediment samples were collected from the Ganga Alluvial Plain (GAP) and its weathering products (from the Gomati
River) for the study of As distribution and mobilization. These sediment samples were analyzed by Instrumental Neutron Activation
Analysis (INAA) method using Cirus Research Reacter of Bhabha Atomic Research Centre, Mumbai. Average As concentrations in
the GAP sediments (10.44 mg kg−1), the Gomati River bed sediments (1.36 mg kg−1) and the Gomati River suspended sediments (5.30 mg kg−1) were reported. Significant decrease of As content from the alluvial sediments to the river sediments is a clear indication
of its mobilization by chemical weathering processes of mineral biotite. Present study demonstrates the importance of INAA
for quantification and mobilization of As and improves our understanding related to As related environmental issues in northern
India and elsewhere.
Authors:Alok Srivastava, K. Swain, Nicy Ajith, D. Wagh, R. Acharya, A. Reddy, and Uttam Mete
Kidney stones obtained from six patients belonging to the stone belt region of India (Punjab) were analyzed for inorganic
constituents using instrumental neutron activation analysis (INAA) and energy dispersive X-ray fluorescence (EDXRF) techniques.
For INAA, samples were irradiated along with IAEA RM Soil 7 as reference standard in CIRUS reactor, BARC, Mumbai. Gamma activity
of irradiated samples was measured using a 45% relative efficiency HPGe detector coupled to 8 k channel analyzer. EDXRF method
was used for determination of concentration of Ca. The concentrations of ten elements namely Ca, Na, K, Mn, Co, Cr, Zn, Br,
Sm and Cl, are reported and discussed.
Authors:J. Rao, E. Senthilvadivu, N. Seshadreesan, R. Acharya, C. Venkatasubramani, and A. Reddy
The pneumatic fast transfer system position at KAMINI reactor, Indira Gandhi Centre for Atomic Research, India was characterized
by determining the epithermal neutron flux shape factor (α) and the sub-cadmium to epithermal neutron flux ratio (f) for k0-based Neutron Activation Analysis (k0-NAA). For determination of α value, bare, Cd-ratio and Cd-cover methods were employed using dual and multi monitors namely
Au, Zr and Zn. For calculation of f, Au and Zr monitors were used in the case of bare method and Au monitor was used for cadmium ratio and cadmium cover methods.
The determined α-value of PFTS indicated a hard epithermal neutron spectrum and the f value indicated about 96 % thermal neutron
component. For validation of k0-NAA method, reference materials namely NIST SRM 1646a (Estuarine Sediment) and BCS Nb-stabilized Stainless Steel (BCS/SS
No.261/1) were analyzed. The percentage errors of the determined concentration values of elements were within ±5 % with respect
to the certified values and the Z-score values at 95 % confidence level were within ±2 in most of the cases.
Authors:K. Dasari, R. Acharya, K. Swain, N. Lakshmana Das, and A. Reddy
The k0-based internal monostandard neutron activation analysis (IM-NAA) method was used for the analysis of 30 large and non-standard
geometry ancient pottery samples obtained from Buddhist sites of Andhra Pradesh, India. One freshly finished pottery and a
sun-drenched pottery were also analyzed for comparison. Samples were irradiated in thermal column facility of Apsara reactor
and also in graphite reflector position of critical facility of Bhabha Atomic Research Centre. Radioactive assay was carried
out using a 40% relative efficiency HPGe detector coupled to MCA. Concentration ratios of 15 elements with respect to Sc were
determined. The La/Ce values as well as statistical cluster analysis utilizing concentration ratios of elements were used
for grouping/provenance of the potteries.
Authors:Alok Srivastava, D. Pathania, K. Swain, Nicy Ajith, R. Acharya, A. Reddy, and H. Nayyar
The phyto-accumulation efficacy of selenium (Se) from soil by chickpea plant is reported. Chickpea plants were grown in soil
having different concentrations (1–4 mg kg−1) of Se. Samples of soil and different parts of chickpea plants in Se rich soil were analyzed for determination of Se concentrations
by instrumental neutron activation analysis (INAA). Samples were irradiated in self-serve facility of CIRUS reactor, BARC,
Mumbai at a neutron flux of the order of 1013 cm−2 s−1. The gamma activity at 264.7 keV of 75Se (119.8 d) was measured using a 45% relative efficiency HPGe detector coupled to MCA. Dependence of Se distribution in soil
and plants on its spiking concentration was evaluated in this work. The Se concentrations determined in plant parts grown
in control soil and in soil spiked with Se (4 mg kg−1) are in the range of 0.6–0.8 and 65–68 mg kg−1 respectively.
Authors:P. Geetha, N. Karunakara, Ujwal Prabhu, P. Ravi, J. Sudhakar, Nicy Ajith, K. Swain, R. Acharya, and A. Reddy
Instrumental and preconcentration methods of neutron activation analysis (NAA) have been standardized for the determination
of concentration of iodine in grass and cow milk samples, respectively. To study the transfer of iodine from grass to milk,
known quantity of grass spiked with potassium iodide solution was fed to a cow. The spiked grass samples and milk samples,
obtained from the cow after the ingestion of spiked grass, were collected. Iodine was separated from the milk samples chemically
using Dowex 1X8 anion exchange resin. Spiked grass and ion exchange resin samples were neutron irradiated and radioactive
assay was carried out using a 45 % relative efficiency HPGe detector coupled to an 8k channel analyzer. Iodine concentrations
in spiked grass samples were found to be in the range of 1,487–2,002 mg kg−1. Concentration of iodine in milk after 12 h of feeding the cow with spiked grass was 871 ± 56 μg L−1 which was reduced to 334 ± 32 μg L−1 after 48 h.
Authors:R.N. Acharya, K. Sudarshan, A.G.C. Nair, Y.M. Scindia, A. Goswami, A.V.R. Reddy, and S.B. Manohar
The guided thermal neutron beam at 100 MW Dhruva research reactor facility of Bhabha Atomic Research Centre (BARC) was used to carry out prompt gamma-ray neutron activation analysis (PGNAA). The prompt k0-factors have been determined for the isotopes of the elements H, B, K, Co, Cu, Ca, Ti, Cr, Cd, Ba, Hg and Gd with respect to 1951 keV gamma-line of 36Cl. The prompt k0-factors for H, Cl and Cu were also measured with respect to the 1381 keV gamma-line of 49Ti. Different samples like NH4Cl, Ti metal, cobalt chloride and other stoichiometric compounds and pure metals were used for this purpose. Prompt gamma-rays were accumulated using a 22% HPGe detector connected to a PC based 8k MCA in single mode counting. The energy calibration in the range of 100–8500 keV was carried out using gamma-rays from 152Eu and 60Co, and the prompt gamma-rays from 36Cl whereas the absolute detection efficiency for this energy range was determined using 152Eu and prompt gamma-rays from 36Cl and 49Ti.