A nondestructive NAA method based on the reaction 31P(n,γ)32P (T1/2 = 14.23 d) has been developed where the product nucleus, a pure β-emitter with end point energy 1.71 MeV is measured by using
an end window G.M. counter and an Al filter of 27 mg·cm−2. 32P was identified by measuring Eβ using Feather’s analysis and its half-life was found to be 15.3±0.2 days in standard reference materials (SRMs) and samples.
For most reference materials (RMs) from NIST (USA) and IAEA (Vienna), our values agree within ±5% of the certified values.
A variety of biological samples have also been analyzed and our values are in the range; medicinal herbs (n = 43), 0.29–5.23 mg/g; bhasmas (n = 19), 0.09–51.4 mg/g; vegetables (n = 8), 1.85–5.73 mg/g; lentils (n = 6), 2.1–5.5 mg/g; flours (n = 6), 1.3–3.3 mg/g; vegetarian diet (n = 5), 2.41–2.90 mg/g; fish (n = 43), 3.61–36.8 mg/g; human and animal milk (n = 6), 1.24–7.95 mg/g; commercial milk powders (n = 14), 2.76–11.9 mg/g; water from various sources (n = 14), 1–417 µg/l; human and animal blood (n = 9), 1.00–15.0 mg/g; cancerous and healthy breast tissue (n = 60), 1.00–8.63 mg/g; human hair (n = 43), 0.12–5.81 mg/g, where n is the number of samples analyzed. The method is simple, fast, and nondestructive and provides
data within ±5% error limit with a detection limit of 0.1 mg/g.
Authors:D. Choudhury, R. Borah, R. Goswamee, H. Sharmah, and P. Rao
Pyrolysis of petroleum refinery sludge has received global acclamation as a clean conversion technique for providing solution
of sludge disposal as well as efficient resource utilization. This communication reports the kinetics study of pyrolysis of
petroleum refinery sludge. Experiments were carried out by means of thermogravimetric analysis at different heating rates
of 5, 10 and 20�C min−1. The pyrolytic reaction is significant in the temperature range of 200–350�C and analysis and evaluation of kinetic parameters
is done in the 100–500�C region of non-isothermal TG curves obtained in nitrogen atmosphere.
The activation energy is calculated by iso-conversional method, then other kinetic parameters are determined by considering
single reaction and two reaction global kinetic model. Two-reaction model is found to fit satisfactorily the experimental
Authors:R. Choudhury, R. Acharya, A. Nair, A. Reddy, and A. Garg
Four plant parts (leaves, roots, fruits and seeds) of twenty samples of sixteen antidiabetic herbs including three commercially
marketed capsules have been analyzed for 6 minor (Na, K, Ca, Cl, Mg, and P) and 21 trace (As, Ba, Br, Ce, Co, Cr, Cs, Cu,
Eu, Fe, Hg, La, Mn, Rb, Sb, Sc, Se, Sm, Th, V and Zn) elements by instrumental neutron activation analysis (INAA). Further,
Ni, Cd and Pb contents were determined by AAS. Elemental data were validated by simultaneously analyzing reference material
(RM), MPH-2 Mixed Polish Herbs. Several elements such as Cr and V (1–2 μg/g), Rb (10–40 μg/g), Cs (80–300 ng/g), Se (∼100
ng/g) and Zn (25–60 μg/g) play an important role in diabetes mellitus. Interelemental linear correlations have been observed
for Cu vs. Zn (r = 0.89) and Rb vs. Cs (r = 0.87). K/P ratio varies in a narrow range with a mean value of 6.2 ± 1.4. Toxic elements As and Hg were found in <1 μg/g
whereas Cd and Pb were in ∼5 μg/g and <10 μg/g, respectively.
Authors:A. Garg, R. Paul Choudhury, R. Acharya, and A. Reddy
Tobacco smoking/chewing has been a cause of concern because of it being related with oral cancer. It causes stimulation and
ill physiological effects. Ten different brands of spit tobacco, eight gutkaas and five paan masalas have been analyzed for
seven minor (Al, Na, K, Ca, Cl, Mg, and P) and 17 trace (As, Ba, Br, Co, Cr, Cs, Cu, Eu, Fe, Hg, La, Mn, Rb, Sb, Sc, Th, and
Zn) elements by instrumental neutron activation analysis. Also Ni and Pb were determined by atomic absorption spectrophotometry.
Concentration of Cd was below detection limit (<10 mg kg−1) in the tobacco samples. Mg, generally added as MgCO3 to prevent caking, is present as minor constituent in spit tobacco and gutkaas but is below detection limit (<1 g kg−1) in paan masalas. Most elemental concentrations vary in a wide range depending on the nature of chewing tobacco. Spit tobacco
has been found to be more enriched in essential elements (Ca, K, Na, P, Mn, and Rb), whereas gutkaas contain higher concentrations
of Fe, Cr, Cu, and Zn. Paan masalas contain lower contents of other elements but higher content of Hg. Gutkaas also contain
higher amounts of As and Pb. Further glutamic acid has been separated from tobacco leaves and characterized as it might bind
with some elements.
Authors:Madan Lal, R. Choudhury, D. Joseph, H. Bajpai, and C. Tyer
Analysis by Energy Dispersive X-ray Fluorescence spectroscopy of monazite ores from Kerala /Chavara and Manavalakurichi/, Orissa /Chattrapur/ and Tamil Nadu /Tirunelveli/ has been carried out for the determination of their elemental composition using109Cd /annular/ and241Am /disc/ radioisotope sources. The elements Y, Zr, Mo, Pb, Th and U were analyzed using a109Cd source, and the elements La, Ce, Pr, Nd, Sm, Gd and Dy were analyzed using the241Am source in side source geometry. Quntitative results on these 13 elements present in these ores were obtained by the EDXRF technique. It was seen that despite the diverse geological settings, there is remarkable similarity in the elemental composition of these ores, although some trace elements do show certain variations from sample to sample. These results are presented and discussed in this paper.
Authors:R. Choudhury, A. Kumar, A. Reddy, and A. Garg
Trikatu, an Ayurvedic formulation of three dried powder spices, ginger, black pepper and pipali in equal proportion is widely used
to promote digestion, assimilation and bioavailibility of food. It works synergistically, and hence, is more effective than
an equal amount of any of its three ingredients taken separately. Five different brands and its three constituents were analyzed
for 31 elements by instrumental neutron activation analysis (INAA) using 5-minute and 6-hour thermal neutron irradiation followed
by high-resolution γ-ray spectrometry. Heavy toxic metals Cd, Ni and Pb determined by atomic absorption spectrometry (AAS)
were found below permissible limits. Most elements in different brands vary in a narrow range. Ginger is particularly enriched
in Ca, Fe, Mg and Mn whereas black pepper is enriched in Cr, Se, P and Zn. Cu/Zn shows linear relationship (r = 0.92) with Cu whereas Fe and Mn exhibit inverse correlation (r = −0.89) in different brands. Hydro distillation of pipali yielded an essential oil whereby 10 organic constituents were
identified by GC-MS. Also barbituric and tannic acids were isolated from the aqueous methanolic extract of pipali.
Fourteen samples of fresh curry leaves (Murraya Koenigii) were collected from 13 states of India and analyzed for 6 minor (Ca, Cl, K, Mg, Na and P) and 14 trace (Br, Ce, Co, Cr, Cs,
Fe, Hg, Mn, Rb, Sb, Sc, Se Th and Zn) elements by 2-minute irradiation in a reactor followed by high resolution g-ray spectrometry.
Peach Leaves (SRM-1547) and Mixed Polish Herbs (MPH-2) were used as comparator standards. Phosphorus was determined by counting
the b-activity from 32P using an end-window GM counter. Most elements were found to vary in a wide range depending on their origin of location,
e.g., Na (104-455 mg/g), K (10.3-30.3 mg/g), Ca (9.44-28.3 mg/g), Mg (1.14-7.19 mg/g), P (0.43-1.69 mg/g), Mn (24.8-63.0 mg/g),
Fe (72.5-195 mg/g), Se (40.1-131 ng/g) and Zn (7.90-70.5 mg/g). Variation in the elemental concentrations of the same species
of different origin may be attributed to ecological and geographical variations. Further, column and thin layer chromatography
were used for separating three organic constituents from the ethanolic extract; 3-methylthiopropanenitrile; 1,2-benzenedicarboxylic
acid, mono (2-ethylhexyl ester) and 1-penten-3-ol and characterized by IR and GC-MS. Inorganic elements may be present as
complexes with the organic compounds.
Authors:S. Chhillar, R. Acharya, S. Sodaye, K. Sudarshan, S. Santra, R. Mishra, C. Kaushik, R. Choudhury, and P. Pujari
Barium borosilicate glass (BaBSG) is proposed as a potential candidate for vitrification of nuclear waste generated from thoria
based nuclear reactors. Along with fission products, activation products and many inactive chemicals, like fluorine in the
form of HF are expected to be present in the dissolver solution with nuclear waste. As vitrification occurs at high temperature,
it is important to quantify fluorine in BaBSG. Due to its complex matrix, most of the wet chemical and nuclear analytical
methods encounter problems in the estimation of fluorine. Particle induced γ-ray emission (PIGE) method has been standardized
for non-destructive determination of fluorine contents in BaBSG samples utilizing measurement of prompt gamma-rays from 19F (p, p’γ) 19F reaction. Experiments have been carried out with thick pellet targets prepared in cellulose matrix using 4 MeV proton beam
from the folded tandem ion accelerator at BARC, Mumbai. For obtaining current normalized count rate of interest, beam current
variation was monitored by the Rutherford backscattering spectrometry (RBS) method as well as by the in situ approach using
an externally added element sensitive to PIGE. In this paper standardization of PIGE methods for F determination, validation
of methods using synthetic samples, and application to BaBSG samples are reported.