A quantitative densitometric high-performance thin-layer chromatographic (HPTLC) method has been established for analysis for two anti epileptic drugs, levetiracetam and oxcarbazepine in tablets. Separations on silica gel 60 F
HPTLC plates with toluene-acetone-methanol, 6:2:2 (
), as mobile phase enabled satisfactory resolution of the two drugs. This system afforded well resolved compact bands for levetiracetam and oxcarbazepine at
0.45 ± 0.02 and 0.55 ± 0.02, respectively. Densitometric scanning was performed in absorbance/reflectance mode at 200 and 261 nm. The method was successfully validated for precision, robustness, ruggedness, and recovery. The drugs were also subjected to photodegradation studies; oxcarbazepine was degraded in 9 h and levetiracetam was not degraded even after a long period. The method was found to be accurate and compatible with the conditions used.
Authors:A. Pradeep, G. Nagaraju, P. Sarita, A. Rao, B. Reddy, G. Rao, and S. Reddy
A number of essential trace elements play a major role in various metabolic pathways and in many diseases like autoimmune,
neurological and psychiatric. This study is undertaken with an aim to evaluate the levels of different trace elements in the
scalp hair samples of patients suffering from alcohol induced psychosis by particle induced X-ray emission technique (PIXE).
It is observed that Fe (p < 0.0005), Cu (p < 0.001) are significantly higher in the hair samples of alcohol induced psychosis patients compared to those in normals
while concentrations of Mn (p < 0.005) and Zn (p < 0.0001) are lower. The concentrations of Co and Ni in the hair samples are found to be in consonance with the concentrations
in the normals.
Authors:A. Nair, A. Reddy, R. Acharya, P. Burte, and S. Manohar
A chemical neutron activation analysis method to determine trace amounts of palladium present in the uranium ores has been
developed. Palladium was concentrated on an anionic exchanger to purify from large amounts of uranium, iron and copper that
were present in the ore. The resin in which Pd was adsorbed was neutron irradiated and the activation product109Pd was assayed through its daughter109mAg by low energy photon spectrometry to estimate palladium. Both the 88 keV gamma-line and the 22 keV X-ray line (arising
out of the internal transition of109mAg) were used to arrive at the concentration values by a standard comparison technique. A thin window Si(Li) detector and
an HPGe detector were used for the radioactive assay. Detection limits and the advantage of using the X-ray line of Ag over
that of the gamma-line were discussed. An absolute detection limit of 0.12·10−9 g could be arrived at by the use of the 22.10 keV X-ray line in an interference-free condition.
Authors:P. Santhi, M. Reddy, T. Ramamohan, and A. Damodaran
Synergism in the extraction of Ce(III) from thiocyanate solutions has been investigated using mixtures of 2-thenoyltrifluoroacetone (HTTA) and bis-2-ethylhexyl sulfoxide (B2EHSO) or di-n-octyl sulfoxide (DOSO) in benzene. A very high synergistic enhancement of the order of 105 has been observed. If a mixture of both dialkyl sulfoxides (B2EHSO+DOSO) is used, an additional synergistic effect is found due to the formation of a mixed, solvated complex when both reagents are added to the metal chelate. These extraction data have been analyzed theoretically with the aid of a computer by taking into account complexation of the metal in the aqueous phase by inorganic ligands and plausible complexation in the organic phase. The equilibrium constants of the various product species have been deduced by non-linear regression analysis.
Authors:R. Acharya, P. Burte, A. Nair, A. Reddy, and S. Manohar
Multielement analysis was carried out in two samples of natural rubies obtained from Kenya and Tanzania and a synthetic ruby obtained locally. The trace element profile was used to characterise the ruby samples. Instrumental Neutron Activation Analysis (INAA) by the single comparator (K0 method) was used to determine the concentrations of 22 elements with gold as the comparator. High resolution -ray spectrometry was employed for radiometric assay of the activation products. The accuracy and precision were evaluated by analysing standard reference materials such as USGS-W-1 and AGV-1 and were found to be satisfactory.
Authors:P. Reddy, B. Rao, B. Polaiah, K. Aruna, and B. Rangamannar
A radiochemical displacement method has been developed for the determination of nickel and cobalt based on the release of Zn-65 from labelled Zn(PAN)2 [1-(2-pyridylazo) 2-naphthol] complex in chloroform. The displacement behavior of Zn-65 by nickel and cobalt was studied in the pH range 5–7.5. The effect of various ions on the displacement was also examined. 2–20 g of nickel and cobalt was determined by the aid of calibration plots.
Authors:P. Santhi, M. Reddy, T. Ramamohan, and A. Damodaran
Synergism in the extraction of Lu(III) from thiocyanate solutions has been investigated using mixtures of bis-2-ethylhexyl sulfoxide (B2EHSO) and 2-thenoyltrifluoroacetone (HTTA) or di-n-octyl sulfoxide (DOSO) or tri-n-octylphosphine oxide (TOPO) in benzene. For comparison, the synergistic extraction of Lu(III) from perchlorate solutions has also been investigated with a mixture of B2EHSO and HTTA. These extraction data have been analyzed theoretically with the aid of a computer by taking into account complexation of the metal in the aqueous phase by inorganic ligands and plausible complexation in the organic phase. The equilibrium constants of the various product species have been deduced by non-linear regression analysis.
Authors:Charu Dwivedi, Naina Raje, Manmohan Kumar, A. Reddy, and P. Bajaj
The present work describes the application of radiotracer technique for studying uptake of arsenic on titanium hydroxide,
commercial titanium dioxide (TiO2) powder (anatase) and synthesized mesoporous titania beads in acidic, neutral, and alkaline conditions. Sol–gel templating
method was used to prepare titania–polysaccharide composites, with different polymer contents. Mesoporous titania was obtained
by heat treatment of the composite beads in a controlled environment. The synthesis process was optimized, using thermogravimetry
analysis. X-ray diffraction patterns confirmed the formation of anatase pure phase titania (TiO2) at 700 °C in different environments, and scanning electron microscopy studies confirmed uniform pore size distribution.
The effect of surface area, polymer content and pH on uptake of arsenic(III) and (V) on the synthesized titania beads was
also investigated. Arsenic(V) was found to be retained quantitatively on the titania beads synthesized from 0.8% polymer content
titania–polymer composite precursor in neutral to alkaline conditions. Details of the results obtained are discussed.
Authors:R. Singhal, P. Sharma, M. Bassan, H. Basu, and A. Reddy
During this work selective separation of uranium from rock phosphate and columbite mineral was done before its quantitative
estimation by using Inductively Coupled Plasma Optical Emission Spectrometery (ICP-OES). Uranium from the rock phosphate and
columubite was extracted by sodium peroxide fusion followed by leaching in 2 M HNO3. To avoid spectral interference in the estimation of uranium by ICP-OES, the selective separation of uranium from the leachate
was carried out by using two different extractants, 30% Tributyl Phophates (TBP) in CCl4 and a equi-volume mixture of Di(2-ethylhexyl) phosphoric acid (D2EHPA) & TBP in petrofin. Uranium was stripped from the organic
phase by using 1 M ammonium carbonate solution. Determination of uranium by ICP-OES was done after dissolving the residue
left after evaporation of ammonium carbonate solution in 4% HNO3. The concentration of the uranium observed in the rock phosphates samples was 40–200 μg g−1 whereas in columbite samples the concentration range was 100–600 μg g−1. Uranium concentration evaluated by ICP-OES was complimented by gamma & alpha spectrometry. Concentration of uranium evaluated
by gamma spectrometry in case of rock phosphate and coulmbite was in close agreement with the uranium content obtained by
ICP-OES. Uranium determination by alpha spectrometry showed only minor deviation (1–2%) from the results obtained by ICP-OES
in case of rock phosphates whereas in case of coulmbites results are off by 20–30%.