Authors:J. N. Sateesh, G. V. Subba Reddy, K. N. Jayaveera, and S. Dhayalamurthi
The objective of the current study is to develop a validated specific stability-indicating isocratic reversed-phase liquid chromatographic method for the quantitative determination of levofloxacin and its related substances in pharmaceutical dosage forms in the presence of degradation products and its process-related impurities. Forced degradation studies were performed on levofloxacin as per the International Conference on Harmonisation (ICH)-prescribed stress conditions using acid, base, oxidative, water hydrolysis, thermal stress and photolytic degradation to show the stability-indicating power of the method. Significant degradation was observed during oxidative stress; minor degradation was observed in acidic stress and no degradation was observed in other stress conditions. The chromatographic method was optimized using the samples generated from forced degradation studies and the spiked impurity solution. The analysis was carried out with a 50 mm length × 4.6 mm i.d., 3.0 μm particle size YMC Pack Pro-C18 column using the mobile phase consisting of a mixture of 1.0% (v/v) triethylamine in water with pH adjusted to 6.30, using orthophosphoric acid, methanol and acetonitrile (7.7:1.3:1.0) pumped at a flow rate of 0.8 mL min−1 with ultraviolet (UV) detection at 235 nm. The limit of detection and the limit of quantification for the levofloxacin and its process-related impurities were established. The stressed test solutions were assayed against the qualified working standard of levofloxacin and the mass balance in each case was in between 99.1% and 99.9%, indicating that the developed liquid chromatography (LC) method was a stability-indicating technique. Validation of the developed LC method was carried out as per ICH requirements.
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:H. Basu, R. Singhal, M. Pimple, V. Manisha, M. Bassan, A. Reddy, and T. Mukherjee
During this work highly particle reactive nature of thorium was exploited for the separation of Th from aquatic stream containing
U/Th. The Kd value of Th(IV) ions is 106 which is two order of magnitude higher than uranium (IV & VI). Laboratory simulated experiments were conducted to study the
preferential removal of thorium by using siliceous material having particle size of about 2,000 μm. Siliceous material was
prepared by decomposing the organic layer on soil particles by giving treatment with HNO3 and H2O2. Experimental solutions were generated by spiking the surface water with Th (NO3)4 and UO2(NO3)2. Experimental results shows preferential uptake of Th compared to U by siliceous material. This association is further improved
by coating the siliceous material with high and low molecular weight organic materials i.e. humic and fulvic acid, respectively.
Characterization of the organic material was done by ATR–FTIR whereas determination of Th was done by ICP-OES and alpha spectrometry.
Experimental results clearly showed that Th and U sorption capacity is 1 and 0.3 μg mg−1 (w/w), respectively, in case of siliceous material. Thorium sorption is increased five and eight times in the case of coating
with fulvic acid and humic acid, respectively. Whereas the same does not shows any pronounced impact on sorption of uranium.
Authors:A. Kumar, A. G. C. Nair, A. V. R. Reddy, and A. N. Garg
Twenty bhasmas based on Ca, Fe, Zn, Hg, Ag, K, As, Cu, Sn and gemstones have been analyzed for main constituent elements along
with minor (Na, K, Mg, Ca, P), trace (Cr, Mn, Fe, Co, Cu, Zn, Hg) and toxic elements by instrumental neutron activation analysis
(INAA) including their C, H, N and S contents. Siddhamakaradhwaja, an Hg preparation and Swet parpati of K were found to be
stoichiometrically HgS and KNO3
Authors:G. Murthy, M. Sivaiah, S. Kumar, V. Reddy, R. Krishna, and S. Lakshminarayana
The applicability of zirconium phosphate-ammonium molybdophosphate (ZrP-AMP) for the efficient removal of cesium from aqueous
acidic solutions by adsorption has been investigated. The adsorption data analysis was carried out using the Freundlich, Dubinin-Raduskevich
(D-R) and Langmuir isotherms for the uptake of Cs in the initial concentration range of 3.75.10-5-7.52.10-3 mol.dm-3 on the ZrP-AMP exchanger from nitric acid medium. The mean free energy (E) values for the adsorption of Cs were obtained from the D-R isotherm. Equilibrium adsorption values at different temperatures
have been utilized to evaluate the change in enthalpy, entropy and free energy (ΔH°, ΔS°, ΔG°). The adsorption of cesium on the ZrP-AMP exchanger was found to be endothermic.
Authors:A. N. Garg, A. Kumar, A. G. C. Nair, and A. V. R. Reddy
Eight different brands of Trifala and its three constituents, Amalaki (Embilica officinalis), Bibhitaki (Terminalia bellirica) and Haritaki (T.chebula) were analyzed for 6 minor (Na, K, Mg, Ca, Cl and P) and 19 trace (Al, Ba, Br, Co, Cr, Cs, Fe, Eu, Hf, Hg, La, Mn, Rb, Sb, Sc, Se, Th, V and Zn) elements by instrumental neutron activation analysis (INAA). Two candidate reference materials Tea Leaves (TL-1) and Mixed Polish Herbs (MPH-2) were also analyzed as a part of Intercomparison Study besides several reference materials (RMs) for quality control. The samples along with RMs were irradiated with thermal neutrons in APSARA/Dhruva reactors at BARC, Mumbai and their activity measured on HPGe detector and 8K MCA system. Also Ni, Cu, Cd and Pb contents were determined by AAS. Bibhitaki is found to be enriched in Fe (0.98 mg/g), P (1.10 mg/g), Co (1.74 mg/g) and Se (240 ng/g) including alkali and alkaline earth metals. Availability of many nutrient elements such as Mg, Ca, K, Fe, and Se in Trifala is attributed to its usefulness in the treatment of liver disorder, heart ailments, hepatic diseases and cancer, as expectorant, powerful eye rejuvenator and an antioxidant.
Authors:G. Reddy, Pritty Rao, J. Ramana, S. Vikramkumar, V. Raju, and Sanjiv Kumar
The paper describes the determination and depth profiling of oxygen in thin oxide films using 18O(p,α)15N nuclear reaction. The excitation function of 18O(p,α)15N nuclear reaction exhibits a resonance at 629 keV and a plateau at 730 keV with uniform cross-section. The resonance is used
to determine the depth profile of oxygen in films while the plateau, to estimate its overall concentration. The resonance,
characterized by a width of 2.1 keV enables high-depth resolution (~20 nm) measurements and has a probing depth of more than
a micron. The paper presents depth profile measurements of oxygen in several metal oxide films (SiO2, TiO2 and HfO2) using this resonance. Possible interferences arising from 15N(p,α)12C, 19F(p,α)16O and 11B(p,α)2α nuclear reactions are also discussed. It has been shown that it can serve as a suitable alternative to 3.05 MeV 16O(α,α)16O resonant scattering which is generally used for depth profiling oxygen. It is, in fact, more reliable and precise in materials
that witness significant large angle multiple scattering. It can also be advantageously used to monitor 18O, when used as a tracer.
Authors:R. Singhal, H. Basu, M. Bassan, M. Pimple, V. Manisha, D. Avhad, P. Sharma, and A. Reddy
Direct determination of uranium in the concentration range of 8 μg L−1 to mg L−1 in water samples originating from different geochemical environments has been done using Inductively Coupled Plasma-Optical
Emission Spectroscopy (ICP-OES). Uranium detection with 2–3% RSD (relative standard deviation) has been achieved in water
samples by optimizing the plasma power, argon and sheath gas flow. These parameters were optimized for three different emission
lines of uranium at 385.958, 409.014 and 424.167 nm. Interference arising due to the variation in concentration of bicarbonate,
sodium chloride, calcium chloride, Fe and dissolved organic carbon (DOC) on the determination of uranium in water samples
was also cheeked as these are the elements which vary as per the prevailing geochemical environment in groundwater samples.
The concentration of NaHCO3, CaCl2 and NaCl in water was varied in the range 0.5–2.0%; whereas Fe ranged between 1 and 10 μg mL−1 and DOC between 0.1–1%. No marked interference in quantitative determination of uranium was observed due to elevated level
of NaHCO3, CaCl2 and NaCl and Fe and DOC in groundwater samples. Concentration of uranium was also determined by other techniques like adsorptive
striping voltametry (AdSv); laser fluorimetry and alpha spectrometry. Results indicate distinct advantage for uranium determination
by ICP-OES compare to other techniques.
Authors:K. Gopal, E. Pradeepthi, V. Gopi, S. Khayum Ahammed, Y. Sreenivasulu, M. Reddy, V. Baranwal, and K. Purushotham
Huanglongbing (HLB), previously known as citrus greening disease (CGD) is one of the most destructive disease of citrus and responsible for decline of citrus orchards in Andhra Pradesh (A. P) and other citrus growing areas in the country. A preliminary survey on prevalence of HLB associated with citrus was carried out in three major sweet orange growing districts of A. P and the results revealed that a high incidence of 14.5% was recorded in Prakasam district followed by Kadapa (13.18%) and Nellore (12.59%). The DNA extracted from different plant parts of acidlime, i.e. bark, midrib, vein and lamina by CTAB and SS Tris-EDTA methods were subjected to PCR amplification. An amplification product of 1150 bp was observed in bark, midrib and vein. However, no amplification was observed in leaf lamina. Between CTAB and SS Tris-EDTA method, DNA from SS Tris-EDTA method yielded bright band compared to CTAB method. Detection of HLB in sweet orange was done from December 2004 to April 2005 at fortnight interval. It was observed that an excellent amplification product of 1150 bp was observed from December 2004 to February 2005. From March onwards a mild amplification of 1150 bp was observed in both the methods. So it can be concluded that winter season will be the suitable period for detection of the pathogen. Between these two methods of DNA extraction CTAB method was useful for detection of HLB in midrib and veins while SS Tris-EDTA method was useful for detection in bark of sweet orange.
Authors:S. Abdul Sattar, B. Seetharami Reddy, V. Koteswara Rao, A. Pradeep, G. Naga Raju, K. Ramanarayana, P. Madhusudana Rao, and S. Bhuloka Reddy
Trace elemental analysis was carried out in various parts of 10 anti-epileptic medicinal plants using PIXE technique. A 3 MeV
proton beam was used to excite the samples and spectra were recorded using a Si(Li) detector. Data analysis was done using
Gupix Software. The elements Cl, K, Ca, Ti, Mn, Fe, Ni, Cu, Zn, Br and Sr were identified and their concentrations estimated.
The presence of some of these trace elements is correlated with the anti-epileptic curative property of these plants.