Recent Publications
 Chinedu G. Otu and Emmanuel O. Otu, The thermodynamics of extraction of bismuth by p,p'-di(2-ethylhexyl)ethylene and  methylene-diphosphonic acids.  Proceedings of the International Solvent Extraction Conference, Tucson, AZ, ISEC2008, 1139-1144.

Thaddaeus Hannel, Emmanuel O. Otu and Mark P. Jensen, Thermochemistry of the extraction of bismuth (III) with Bis(2-ethylhexyl)phosphoric and 2-Ethylhexylphenylphosphonic acids. Solvent Extraction and Ion Exchange (SXIX) 25, 241 – 256, 2007

Thermodynamics of the extraction of bismuth with mono-2-ethylhexyl phosphoric acid. Proceedings of the International Solvent Extraction Conference, Beijing China, ISEC2005, pp206-211

Melanie M. Huff and Emmanuel O. Otu, Thermodynamics of the extraction of lead, copper, cadmium, cobalt and nickel with mono-2-ethylhexyl phosphoric acid. Submitted to Solvent Extraction and Ion Exchange 2004, 22(4) 695-712

Johna M. Arnold and Emmanuel O. Otu, Effect of temperature on the synergistic extraction of some lanthanides by 2-ethylhexyl phenylphosphonic acid and micelles of dinonylnaphthalene sulphonic acid. SXIX 2004, 22(3) 415-428 

L. Nash, R. Chiarizia, Marian Borkowski, Paul G. Rickert and Emmanuel O. Otu, Radioanalytical Techniques and the Characterization of New Separations Reagents. American Chemical Society Symposium Series No. 868 Radioanalytical Methods in interdisciplinary Research.  Fundamentals in Cutting-Edge Applications.  Chapter10. Editors: Carola A. Laue and Kenneth L. Nash.  ISBN: 0-8412-3837-5  (2003).

Emmanuel O. Otu and R. Chiarizia, Temperature effect on the extraction of Am(III), U(IV) and Sr(II) by dialkyl-substituted diphosphonic acids.  Separation Science and Technology 2003, 38(12,13) 2619-2636.

Emmanuel O. Otu and R. Chiarizia, Thermodynamics of the extraction of some metal ions by dialkyl-substituted diphosphonic acids, Proceedings of the International Solvent Extraction Conference, Cape Town, South Africa, K.C. Sole, P.M. Cole, J.S. Preston, D.J. Robinson (Eds), The South African Institute of Mining and Metallurgy, 2002, vol. 1, 408-413.

Emmanuel O. Otu, Renato Chiarizia, Paul G. Rickert and Kenneth L. Nash, The extraction of Americium and Strontium by p,p’-di(2-ethylhexyl) benzene-1,2-diphosphonic acid. SXIX 2002, 20(6) 607-632.

Emmanuel O. Otu and R. Chiarizia, Thermodynamics of the extraction of metal ions by dialkyl-substituted diphosphonic acids. Part II. The U(VI) and Sr(II) Case, SXIX 2001, 19(6) 1017-1036.

Emmanuel O. Otu and R. Chiarizia, Temperature effects in the extractions of metal ions by dialkyl-substituted diphosphonic acids. I. The Am(III) Case, SXIX 2001,19(5) 885-904.

E. Otu and J.J Wilson, Supercritical carbon dioxide elution of gold-cyanide complex from activated carbon, Separation Sci. Technol., 2000, Vol. 35, pp.1879-1886.

E. Otu, The thermodynamics of synergistic extraction of bismuth by 2-ethylhexyl phenylphosphonic acid and micelles of dinonylnaphthalene sulphonic acid, Thermochimica Acta, 1999, Vol. 329, pp.117-121.

E. Otu, The effect of temperature on the synergistic extraction of thorium(IV) and uranium(VI) by 2-ethylhexyl phenylphosphonic acid and micelles of dinonylnaphthalene sulphonic acid, Solvent Extraction and Ion Exchange, 1998, Vol. 16, pp.1161-1176.

E. Otu, Elution of gold from activated carbon using supercritical carbon dioxide, Separation Sci. Technol., 1997, Vol. 32, pp.1107-1114.

 E. Otu, The synergistic extraction of uranium and thorium by 2-ethylhexyl phenylphosphonic acid and micelles of dinonylnaphthalene sulphonic acid,  Solvent Extraction and Ion Exchange, 1997, Vol. 15, pp.1-13.

 E. Otu and A.D. Westland, Low temperature 31P NMR study of the extraction of lanthanum with 2-ethylhexyl phenylphosphonic acid, Solvent Extraction and Ion Exchange, 1996, Vol. 14, pp.567-583.

 E.M. Pepe and E. Otu, The synergistic extraction of bismuth and zinc by 2-ethylhexyl phenylphosphonic acid and micelles of dinonylnaphthalene sulphonic acid, Solvent Extraction and Ion Exchange, 1996, Vol. 14, pp.247-262.

 E.Otu, J.J. Byerley and C.W. Campbell, Ion chromatography of cyanide and metal cyanide complexes: Review. J. Inter. Environ. Anal. Chem., 1996, Vol. 63, pp.81-90.

 E.Otu, M. Adams, J. Szubra, M. Kozliner and J. Pawlisyzn, Portable thermal pump for supercritical fluid delivery, Anal. Chem., 1995, Vol. 67, pp.212-219.

 E.Otu, J.J. Byerley and C.W. Campbell, Inorganic modifiers in ion pair chromatographic separation of gold cyanide, Analyst 1993, Vol. 118, pp.1277-1280.

 E.Otu and J. Pawlisyzn, Solid phase microextraction of metal ions, Mikrochimica Acta 1993, Vol. 112. pp.41-46.

 E.Otu, J.J. Byerley and C.W. Campbell, Kinetic modeling of the multi-cycle adsorption of gold on activated carbon in the presence of foulants, Canadian J. of Chem. Eng., 1993, Vol. 71, pp.925-933.

Emmanuel O. Otu, John J. Byerley and Campbell W. Robinson, Anion exchange chromatography of mixed cyano complexes: separation and determination of gold cyano complexes, Au(CN)2-, Analyst 1992, 117, 1145-1149.

 Emmanuel O. Otu and Alan D. Westland, Solvent Extraction with Sulphonic acids, SXIX 1991, 9, 875-883.

 Emmanuel O. Otu and Alan D. Westland, The thermodynamics of Extraction of some Lanthanide and other ions by 2-ethylhexyl phenylphosphonic acid, SXIX 1991, 9, 607-621.

 Emmanuel O. Otu and Alan D. Westland, Solvent Extraction with mono-acidic organophosphonic esters, SXIX 1990, 8, 759-781.

Emmanuel O. Otu and Alan D. Westland, The thermodynamics of Extraction of some Lanthanide and other ions by dinonylnaphthalene sulphonic acid, SXIX 1990, 8, 827-842.

Emmanuel O. Otu and Alan D. Westland, Liquid-liquid Extraction of Some M(II) and M(III) ions with 2-ethylhexyl phenylphosphonic acid, Polyhedron 1989, 8, 1307-1313.

Presentations (*student presenter; **student research participant)
Kara F. Curry** and Emmanuel O. Otu, Extraction of bismuth by Cyanex 272 into supercritical CO2. International Solvent Extraction Conference, Tucson, AZ, Sept. 15-19, 2008

Chinedu G. Otu** and Emmanuel O. Otu, Temperature effects in the extraction of bismuth by p,p'-di(2-ethylhexyl)ethylene and  methylene-diphosphonic acids.  International Solvent Extraction Conference, Tucson, AZ, Sept. 15-19, 2008

Emmanuel O. Otu, Competitive Extraction of the Rare Earth Elements with p,p'-di(2-ethylhexyl)ethylene and methylene-diphosphonic acids. 232nd Meeting of the American Chemical Society, September 19 – 23, 2006.  San Francisco, CA  

Jason Spencer* and Emmanuel O. Otu, Thermodynamics of the extraction of lanthanide by p,p`-di(2ethylhexyl)ethylenediphosphonic acids. 20th National Conference on Undergraduate Research (NCUR), Asheville, NC April 6 - 8, 2006.

Jason Spencer* and Emmanuel O. Otu, Competitive extraction of the rare earth elements with p,p`-di(2ethylhexyl)ethylenediphosphonic. 2nd Indiana University Southeast Student Conference, April 21, 2006

Sarah R. Dyer* and Emmanuel O. Otu, Competitive extraction of the rare earth elements with p,p`-di(2ethylhexyl)methylenediphosphonic. 2nd Indiana University Southeast Student Conference, April 21, 2006

Thermodynamics of the extraction of bismuth with mono-2-ethylhexyl phosphoric acid. International Solvent Extraction Conference, Beijing China, Sept. 19-23, 2005

 Thaddeaus S. Hannel* and Emmanuel O. Otu, Thermodynamics of the extraction of bismuth with organophosphorus acids, 19th National Conference on Undergraduate Research, Lexington, VA, April 19 – 23, 2005.

Thaddeaus S. Hannel* and Emmanuel O. Otu, Effect of temperature on the extraction of bismuth with organophosphorus acids, 10th Annual Indiana University Undergraduate Research Conference, Indianapolis, February 11, 2005.

Emily M. Tracy* and Emmanuel O. Otu, Effect of temperature on the extraction of lanthanum with dialkyl-substituted diphosphonic acids, 10th Annual Indiana University Undergraduate Research Conference, Indianapolis, February 11, 2005.

Melanie M. Huff* and Emmanuel O. Otu, Extraction of lead, copper, cadmium, cobalt and nickel with di-2-ethylhexyl and mono-2-ethylhexyl phosphoric acid, 18th National Conference on Undergraduate Research, Indianapolis, April 15 – 17, 2004.

Melanie M. Huff* and Emmanuel O. Otu, Thermodynamics of the extraction of lead, copper, cadmium, cobalt and nickel with mono-2-ethylhexyl phosphoric acid, 9th Annual Indiana University Undergraduate Research Conference, Indianapolis, November 7, 2003.   


Shannon G. Wilson* and Emmanuel O. Otu, Supercritical carbon dioxide as solvent in the extraction of copper, lead, nickel and zinc from aqueous acid solutions, Indiana University Undergraduate Research Conference, Indianapolis, November 8, 2002.

Phillip E. Mullins* and Emmanuel O. Otu, Synergistic extraction of the lanthanides by 2-ethylhexyl phenylphosphonic acid and micelles of dinonylnaphthalene sulphonic acid, Indiana University Undergraduate Research Conference, Indianapolis, November 8, 2002.

Emmanuel O. Otu* and R. Chiarizia, Thermodynamics of the extraction of some metal ions by dialkyl-substituted diphosphonic acids, International Solvent Extraction Conference (ISEC), Cape Town, South Africa, March 17-21, 2002.

Kenneth L. Nash*, R. Chiarizia, Marian Borkowski, Paul G. Rickert and Emmanuel O. Otu, Radioanalytical Techniques and the Characterization of New Separations Reagents. American Chemical Society Meeting, Orlando, FL, 2001.

Emmanuel O. Otu* and R. Chiarizia, Temperature effects in the extractions of metal ions by dialkyl-substituted diphosphonic acids. 12th Symposium on Separation Science and Technology for Energy Applications, Gatlinburg, TN, October 15-18, 2001.

Emmanuel O. Otu and R. Chiarizia*, Enthalpy and entropy variations in the extraction of Am(III) by dialkyl-substituted diphosphonic acids. 25th Actinide Separation Conference, Boise, ID, May 14-18, 2001.

Lori B. Milligan* and Emmanuel O. Otu, Solvent-free extraction of bismuth and lead from aqueous nitric acid solutions, 15th National Conference on Undergraduate Research, Lexington, KY; March 17, 2001.

Lori B. Milligan* and Emmanuel O. Otu, The extraction of bismuth and lead using supercritical carbon dioxide as solvent, 11th Annual Argonne Undergraduate Symposium in Science, Mathematics and Engineering, Argonne, IL; November 3 - 4, 2000.

Lori B. Milligan* and Emmanuel O. Otu, Extraction of copper, lead and zinc from aqueous medium using supercritical carbon dioxide as the solvent, Indiana University Undergraduate Research Conference, Kokomo October 20, 2000.

Johna M. Arnold* and Emmanuel O. Otu, Thermodynamics of the synergistic extraction of the lanthanides by 2-ethylhexyl phenyl-phosphonic acid and micelles of dinonylnaphthalene sulphonic acid, 10th Annual Argonne Undergraduate Symposium in Science, Mathematics and Enginering, Argonne, IL; November 5 - 6, 1999.

Johna Arnold* and Emmanuel O. Otu, The synergistic extraction of the lanthanides by 2-ethylhexyl phenyl-phosphonic acid and micelles of dinonylnaphthalene sulphonic acid, Indiana University Undergraduate Res. Conf. Indianapolis, October 28, 1999.

Erin Emery, Matt Rutherford and Emmanuel O. Otu*, Spectroscopic evidence for micellar solubilization in the synergistic extraction of thorium(IV) and uranium(VI) by 2-ethylhexyl phenylphosphonic acid and dinonylnaphthalene sulphonic acid, ISEC99, July 12-16, 1999.

Emmanuel O. Otu, Supercritical fluid Extraction in gold hydrometallurgy, ISEC99, July 12 - 16, 1999.

Matt Rutherford* and Emmanuel O. Otu, The synergistic extraction of bismuth, lead and copper by 2-ethylhexyl phenyl-phosphonic acid and micelles of dinonylnaphthalene sulphonic acid, Indiana University Undergraduate Res. Conf. Indianapolis, November 6, 1998.

Emmanuel O. Otu, Supercritical fluid extraction of some metal inorganic and organic species in human hair, presented at the 8th International Symposium on Supercritical Fluid Chromatography and Extraction, St. Louis, MO, July 12 - 16, 1998.

Emmanuel O. Otu, Science, Technology and Afikpo Culture, presented at Africa Past and Present: a Multi-disciplinary Symposium on Africa, IUS, June 11, 1998

Emmanuel O. Otu, Supercritical carbon dioxide extraction of some metal ions, 20th Annual Midwest Environmental Chemistry Workshop, Indiana University, Bloomington, IN, November 8 & 9, 1997.

Emmanuel O. Otu, The synergistic extraction of some metal ions by 2-ethylhexyl phenylphosphonic acid and micelles of dinonylnaphthalene sulphonic acid, 30th Middle Atlantic Regional Meeting-American Chemical Society (MARM 96), May 24-26, 1996, Villanova, PA.

 Peter Wiese* and Emmanuel O. Otu, The thermodynamics of the synergistic extraction of bismuth and some lanthanides by 2-ethylhexyl phenylphosphonic acid and micelles of dinonylnaphthalene sulphonic acid, The New York Chemistry Student's Association 44rd Annual Undergraduate Research Symposium (NYCSA: 44th AURS) May 4, 1996.

 Teresa De Zayas* and Emmanuel O. Otu, Characterization of complexes formed in the synergistic extraction of bismuth and zinc by 2-ethylhexyl phenylphosphonic acid and micelles of dinonylnaphthalene sulphonic acid, NYCSA: 44th AURS.

 Valerie Reid* and Emmanuel O. Otu, The synergistic extraction of calcium, thorium and uranium by 2-ethylhexyl phenylphosphonic acid and micelles of dinonylnaphthalene sulphonic acid, NYCSA: 44th AURS.

 Nadine Marcellus* and Emmanuel O. Otu, Extraction of organic and inorganic species in human hair using supercritical carbon dioxide, NYCSA: 44th AURS.

 Emmanuel O. Otu, Effect of solvent composition on metal cyanide complexes retention in ion-pair and anion exchange chromatography, MARM 95, May 24-26, 1995, Washington, D.C.

 Raya K. Kouletsis* and Emmanuel O. Otu, The extraction of copper by supercritical carbon dioxide, MARM 95, May 24-26, 1995, Washington, D.C.

 Raya K. Kouletsis* and Emmanuel O. Otu, Extraction of copper-humic acid, copper-EDTA and Copper-acetylacetonate complexes by supercritical carbon dioxide, NYCSA: 43rd AURS, May 6, 1995.

 Eugene M. Pepe* and Emmanuel O. Otu, Synergistic extraction of some metal ions by 2-ethylhexyl phenylphosphonic acid and micelles of dinonyl naphthalene sulphonic acid, NYCSA: 43rd AURS, May 6, 1995.

 Wayne Suhrbier, Emmanuel O. Otu* and Thomas Nalli, Gas chromatographic analysis of glycols in environmental samples, Fifth National Conf. of the Council on Undergraduate Research, June 23-25, 1994, Lewiston, Maine.

 Wayne Suhrbier*, Emmanuel O. Otu and Thomas Nalli, Gas chromatography of glycols in environmental samples, NYCSA: 42rd AURS, May 7, 1994.

 Emmanuel O. Otu*, Catherine L. Arthur, Zhouyou Zhang, M. Chai, Karen D. Buchholz, David W. Porter and Janus  Pawlisyzn, Solvent-free sample preparation for capillary chromatography using solid phase microextraction, 15th Int. Symp. on Capillary Chromatography, May 24-28, (1993), Riva del Garda, Italy.