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Faculty of Applied Sciences

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2013 - 20154

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Author: search.filters.author.Naidu, N. VenkatasubbaHas files: Yes

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Now showing 1 - 4 of 4
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    Seasonal variation and distribution of Anionic Surfactants in and around Tirupati : a famous pilgrim centre in South India
    (Asian Publication Corporation, 2015) Ramanjulu, C.; Naidu, N. Venkatasubba; Kanchi, Suvardhan; Bisetty, Krishna
    This report presents the anionic surfactants concentration in water system collected in and around Tirupati, South India. The concentration of anionic surfactants such as sodium lauryl sulfate, sodium dodecyl sulfate, sodium hexadecyl sulfonate and sodium dodecyl benzene sulfonate were showed a rather homogeneous distribution (except sodium dodecyl benzene sulfonate) within the Tirupati, with high values of 80.0, 90.75, 46.90, 15.10 μg L–1 in Tirupati and slightly less concentration values of 75.0, 60.55, 35.40, 10.0 μg L –1 were found in samples collected from Renigunta Industrial Estate during pre-monsoon and monsoon seasons respectively. High concentration of these surfactants in open wells and open municipal wastewaters in Tirupati may be due to the huge discharge of domestic wastes into the drain system. The concentration of surfactants found in Renigunta Industrial Estate may be due to the direct discharge of industrial wastewater into the environment.
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    Novel Dithiocarbamates for electrochemical detection of Nickel (II) in environmental samples
    (Asian Publication Corporation, 2015-06-22) Niranjan, T.; Kanchi, Suvardhan; Bisetty, Krishna; Naidu, N. Venkatasubba
    Ammonium 4-phenylpiperazine-1-dithiocarbamate (Amm 4-PP-DTC) and ammonium 4-benzylpiperidine-1-dithiocarbamate (Amm 4-BP-DTC) were synthesized for the determination of nickel(II) using catalytic hydrogen currents (CHC’s) technique with DC Polarography. The method was based on the chelation of nickel(II) with Amm 4-PP-DTC/ Amm 4-BP-DTC in presence of NH 4 OH at pH 6.8 to produce catalytic hydrogen current at -1.50V and -1.41 V vs. SCE respectively. Optimized polarographic conditions were established by studying effect of pH, supporting electrolyte (NH4Cl), ligands and metal ion concentration and effect of adverse ions on peak height to improve the sensitivity, selectivity and detection limits of the present method. This technique is successfully applied for the analysis of nickel(II) in different matrices with recoveries ranging from 96.0-99.0 % and the results obtained were comparable with the atomic absorption spectroscopy.
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    The polarographic study of Cobalt(II)-dithiocarbamate complexes at DME
    (IJCAS, 2014) Giridhar, C.; Kanchi, Suvardhan; Niranjan, T.; Naidu, N. Venkatasubba
    Cobalt is a naturally occurring element in the earth’s crust. It is a very small part of our environment and very small amounts are needed for many animals and humans to stay healthy. Cobalt poisoning can occur when exposed to large amounts of cobalt. The aim of this study was to develop a facile, rapid, robust, sensitive and selective methodology for the determination of cobalt(II). Two new ligands, ammonium 2,6-dimethyl morpholine dithiocarbamate (ADMM-DTC) and ammonium 3-methyl piperdine dithiocarbamate (AMP-DTC) were synthesized in the laboratory. The method was based on chelation of cobalt(II) with ADMM-DTC/AMP-DTC in presence of NH4OH at pH 7.2 and 8.2 to produce catalytic hydrogen currents at -1.28 V and -1.38 V vs SCE respectively and prior detected by D.C polarography. Optimized polarogaphic conditions were established by studying effect of pH, supporting electrolyte (NH4Cl), ligand & metal ion concentrations and effect of adverse ions on peak height to improve the sensitivity, selectivity and detection limits of the present method. This technique is successfully applied for the analysis of cobalt(II) in different matrices with recoveries ranging from 93- 98 % and the results obtained were comparable with the differential pulse polarography (DPP).
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    Polarographic catalytic hydrogen wave technique for the determination of copper(II) in leafy vegetables and biological samples†
    (ESG, 2013-03-01) Kanchi, Suvardhan; Singh, Parvesh; Sabela, Myalowenkosi Innocent; Naidu, N. Venkatasubba; Bisetty, Krishna
    An economical, novel, eco-friendly and robust method for the quantification of copper(II) in various leafy vegetables, milk and blood samples has been developed using direct current catalytic hydrogen wave (DC-CHW) technique involving the formation of ammonium salts of piperidine/morpholine dithiocarbamates metal complex. Ammonium piperidine/morpholine dithiocarbamates complexed with copper(II) in the presence of NH4Cl-NH4OH medium at pH 6.5±1 produces CHW’s at -0.35±1 V vs SCE. Consequently, various optimal parameters such as preparation medium, effect of pH, ligand concentration, metal ion concentration and indifferent ions effect on peak height were optimized to enhance the sensitivity and selectivity. The novel aspect in the work address the interaction of ammonium piperidine/morpholine dithiocarbamates with copper(II) were confirmed with cyclic voltammetry (CV) and supported by computational calculations using Density Functional Theory (DFT) methods. Furthermore, the student “t”-test and variance ratio “f”-tests indicated no significant difference between the present method and the differential pulse polarographic (DPP) method.