Ethiopia

University of Addis Ababa

BHAGWAN SINGH CHANDRAVANSHI (Ph.D.)

Research areas

  • Research on Synthesis and Characterization of Organic Analytical Reagents, Solvent Extraction (Metal Ions), Spectrophotometry (Metal Ions and Organic Compounds), Gravimetry (Metal Ions), and Electrochemical Behavior of Organic Reagents and Metal Complexes
  • Supervised M.Sc. Theses and Senior Students Research Projects on Solvent Extraction (Metal Ions), Spectrophotometry (Metal Ions and Organic Compounds), Ion Selective Electrodes Potentiometry (Inorganic and Organic Anions), Synthesis and Characterization of Coordination Compounds, and Electrochemical Behavior of Organic Reagents and Metal Complexes
  • My current research interests are in the field of Voltammetric Determination of Metal Ions, Carbon Paste Electrodes, Ion Selective Electrodes Potentiometry of Organic and Inorganic Ions, Solvent Extraction and Spectrophotometry of Metal Ions and Organic Compounds, and Synthesis and Characterization of Coordination Compounds.

Selected Publications

  1. Determination of Tantalum with Hexafluorotantalate(V)-Selective Coated Graphite Electrode, B. Tewolde, B.S. Chandravanshi and Ghirma Moges, Mikrochim. Acta, 1997, 126, 45-51.
  2. Hexafluorotantalate(V)-Selective Coated Graphite Electrode Based on Malachite Green, B. Amare, B.S. Chandravanshi, Ghirma Moges, and N. Megersa, Anal. Lett., 1997, 30, 457-474. 43. Liquid Membrane Electrode Based on Brilliant Green-Hydrogen Phthalate Ion Pair, N. Negash, G. Moges and B.S. Chandravanshi, Chem. Anal., 1997, 42, 579-588.
  3. Ion-pair Extraction Constants of Some Anions and Selectivity of Liquid Membrane Electrodes  Based on Crystal Violet and Brilliant Green, N. Negash, B.S. Chandravanshi and G. Moges,  Bull. Chem. Soc. Ethiop., 1997, 11, 93-99.
  4. Extraction and Spectrophotometric Determination of Vanadium(V) with N-Phenylcinnamo- hydroxamic Acid and Azide, A. Abebaw and B.S. Chandravanshi, Chem. Anal., 1998, 43, 33-40.
  5. Electrochemical Behavior of N-Phenylcinnamohydroxamic Acid Incorporated into Carbon Paste Electrode and Adsorbed Metal Ions, H. Alemu and B.S. Chandravanshi, Electroanalysis,  1998, 10, 116-120.
  6. Differential Pulse Anodic Strippping Voltammetric Determination of Copper(II) with N-Phenylcinnamohydroxamic Acid Modified Carbon Paste Electrodes, H. Alemu and B.S. Chandravanshi, Anal. Chim. Acta, 1998, 368, 165-173.
  7. Differential Pulse Anodic Strippping Voltammetric Determination of Cobalt(II) with N-p-Chlorophenylcinnamohydroxamic Acid Modified Carbon Paste Electrode, T. Refera, B.S. Chandravanshi, and H. Alemu, Electroanalysis, 1998, 10, 1038-1042.
  8. Differential Pulse Anodic Strippping Voltammetric Determination of Lead(II) with N-p-Chlorophenylcinnamohydroxamic Acid Modified Carbon Paste Electrode, T.H. Degefa, B.S. Chandravanshi, and H. Alemu, Electroanalysis, 1999, 11,1305-1311.
  9. 1 0. Differential Pulse Anodic Strippping Voltammetric Determination of Cadmium(II) with N-p-Chlorophenylcinnamohydroxamic Acid Modified Carbon Paste Electrode, Kidane Fanta and B.S. Chandravanshi, Electroanalysis, 2001, 13, 484-492.

  __________________________________________________________________________________________

NEGUSSIE MEGERSA (Ph. D.)

Research Interests

  • Trace level extraction, enrichment and determination of micro pollutant in environmental matrices, method development for detoxification and complex formation of pesticides in environmental waters, ion selective electrode methods of analysis and spectrophotometric determination of elements and ions in ores and mixtures.

Selected publications

  1. N. Megersa and J. A. Jonsson, Trace Enrichment and sample preparation of alkulthio-s-triazine herbicides in environmental waters using a supported liquid membrane technique in combination with high performance liquid chromatography, Analyst, 1998, 123, 225.
  2. L. Chimuka, N. Megersa, J. Norberg, L. Mathiasson and J. A. Jonsson, Incomplete trapping and in supported liquid membrane extraction with a stagnant acceptor for weak bases; Anal. Chem., 1998, 70, 3906.
  3. N. Megersa, T. Solomon and J. A. Jonsson, Supported liquid membrane extraction for sample work up and preconcentration of methoxy-s-triazine herbicide in a flow system, J.Chromatography, A. 1999, 830, 203

  ________________________________________________________________________________________________

TADDESE WONDIMU GODETO (Ph. D)

Research interest

  • Development of fast sample preparation methods for inorganic and organometallic analysis of biological and environmental samples.
  • Speciation in environmental and biological samples, especially of toxic elements coupling chromatography with element specific and non-specific detectors.
  • Water quality management.
  • Waste oil recycling operation
  • Studies on loss of nutrients from soils.

Selected Publications

  1. Dejene A. Tessema, Taddese Wondimu and Walter Kosmus; Study of the trend in the release of purgeable arsenic compounds from soil sample, J. Trace and Microprobe Techniques.
  2. T. Wondimu and W. Goessler, Comparison of closed-pressurized and Open-refluxed digestion systems for trace elements in the residual fuel oil reference material (SRM 1634c), Bull. Chem. Soc. Ethiop., 2000, 14(2), 1-15
  3. T. Wondimu, W. Goessler, and K. J. Irgolic Microwave Digestion of ‘‘Residual Fuel Oil’’ (NIST SRM 1634b) for the Determination of Trace Elements by Inductively Coupled Plasma-Mass Spectrometry, Fresenius J. Anal. Chem., 2000, 367(1), 35-42.
  4. Y. Zulla and T. Wondimu, Practical General Chemistry, Arbaminch Water Technology Institute, Arbaminch, Ethiopia, 1999
  5. T. Wondimu, W. Goessler, M. Abegaz, G. Banuelos, and K. J. Irgolic, Retention Behavior of Inorganic and Organic Selenium Compounds on a Polymer-Based Cation Exchange Column, Phosphorous, Sulfur and Silicon, 1998, 136, 327
  6. T. Wondimu and B.S. Chandravanshi, Extraction and spectrophotometric determination of niobium (V) using N-4-chlorophenylcinnamohydroxamic acid and thiocyanate, Bull Chem. Soc. Ethiop.1990, 4, 1

  _______________________________________________________________________________________________

BERND H U N D H A M M E R (Ph. D.)

Research interest

  • Electrochemistry at solid electrodes including corrosion studies.
  • Analysis of detergents
  • Design and construction of potentiometric (ion selective electrodes) and amperometric sensors.
  • Electrochemical investigations of charge transfer reactions across the interface between two immiscible electrolyte solutions as a model for biological membranes, phase transfer catalysis      and liquid-liquid extraction.
  • Electrochemical synthesis and characterization of conducting polymers.
  • Application of enzyme catalysis for electroanalytical determinations.
  • Design and construction of electrochemical devises.
  • Water and soil analysis.

Selected Publications

  1. Photoinduzierter Elektronentransfer zwischen aromatischen Kohlenwasserstoffen und Phosphoniumsalzen H.J.Timpe, K.Oertel and B.Hundhammer, Z.Chem., 25(1985)144.
  2. Determination of radii of solvated ions in water saturatednitrobenzene/chlorobenzene mixtures, B.Hundhammer, T.Solomon and H.Alemu, Z. phys. Chemie, Leipzig, 266(1985)461.
  3. Investigation of the influence of inert membranes on the selectivity of liquid state ISE by potentiometry and cyclic voltammetry B.Hundhammer, S.Becker and H.J.Seidlitz, in Ion-SelectiveElectrodes (ed. E.Pungor),Akademiai Kiado (1985).
  4. Investigation of ion transfer across the membrane-stabilized interface of two immiscible electrolyte solutions (part I) B.Hundhammer, S.K.Dhawan, A.Bekele and H.J.Seidlitz, J. Electroanal. Chem., 217 (1987) 253.
  5. Investigation of ion transfer across the membrane-stabilized interface of two immiscible electrolyte solutions (part II, analytical application) B.Hundhammer and S.Wilke, J. Electroanal. Chem., 266 (1989) 133.
  6. Transfer of transition metal-terpyridine complexes across the water-nitrobenzene interface H.Alemu, B.Hundhammer and T.Solomon, J. Electroanal. Chem., 294 (1990) 165.
  7. Zur Thiocyanatbestimmung im Serum mittels ionenselektiver Flüssigmembranelektroden H.Below, H.Müller, B.Hundhammer and W.Weuffen, Pharmazie, 45 (1990) 416.
  8. Bestimmung des Thiocyanat-Serumspiegels mittels Fließinjectionstechnik und potentiometrischer Detektion H.Below, B.Hundhammer, H.Müller and W.Weuffen, Wiss. Z. E.-M.-Arndt-Univ. Greifswald, Med.R., 36 (1990) 124.
  9. Ion transfer across the water-o-dichlorobenzene interface B.Hundhammer C.Müller, T.Solomon, H.Alemu and H.Hassen, J. Electroanal. Chem., 319 (1991) 125.
  10. Ion transfer across the water/nitrobenzene interface facilitated by ion association and precipitation, B.Hundhammer, T.Solomon, S.K.Dhawan, T.Zerihun and M.Tessema, J. Electroanal. Chem., 369 (1994) 275.