Cooperative Institute for Research in Environmental Sciences at the University of Colorado Boulder

Robert E. Sievers

Research Interests

For more than 40 years the Sievers research group has conducted fundamental and applied studies in the areas of environmental and analytical chemistry. More recently the group has researched the formation of nanoparticle and microparticle aerosols and has developed innovative methods for synthesis, purification, characterization of useful materials. Carbon dioxide-assisted nebulization provides superior aerosols. 

Professor Sievers is collaborating with medical professionals and engineers to develop new methods for delivery of aerosol particles useful in direct and painless administration of therapeutic drugs and vaccines by inhalation and by sublingual delivery. The drugs are dissolved or suspended in supercritical fluids, and unusually small aerosol particles are formed by rapid decompression to facilitate delivery of the aerosol particles to the alveoli and to allow rapid uptake by the lungs and respiratory tracts. Formation of fine aerosols is expected to become increasingly important in the treatment or vaccination against corona viruses, measles, influenza, infections, stress, COPD, and asthma.
 

Current Research

Development of needle-free and water-free inhalable dry powder aerosol vaccines and pharmaceutical treatments, including cannabinoids from hemp
Substantial effort is directed toward inhalable dry powder aerosol vaccines and pharmaceuticals that require no needle, no purified water for reconstitution, and no electricity or batteries for delivery, which makes them especially useful in developing countries. The Sievers group has published about 200 journal articles and books cited by over 5000 other research groups. He and his colleagues have been awarded about 40 U.S. and foreign patents. Professor Sievers led a team as Principle Investigator of inhalable vaccines funded by FNIH through the Bill and Melinda Gates Foundation in the Grand Challenges in Global Health Initiative. 

There is also interest in our Carbon Dioxide Assisted Nebulization with a Bubble Dryer (CAN-BD), to produce aerosol microparticles small enough (1-5 microns aerodynamic diameter) for cannabinoids to be distributed throughout the moist respiratory tracts of humans and test animals in which diseases can be prevented or alleviated. CBD (cannabidiol) for example may alleviate severe COVID-19. The Sievers research group also manages an experimental hemp plot in East Boulder County to study new cultivars and to develop and improve processing and extraction technologies.
 

Publications

Click here for list of publications



Robert Sievers demonstrates easy vaccination by inhalation of dry powder aerosol vaccines in a needle-free inhaler that he co-invented. Photo credit: Glen Asakawa/CU Boulder

Honors and Awards

  • Tswett Chromatography Medallist, 1981
  • American Chemical Society Colorado Section Award, 1985
  • Dimick Award in Chromatography, 1992
  • Thomas Jefferson Award, 2001
  • Robert Stearns Award, 2003
  • Pinnacle of Inventorship Award, 2004
  • ACS Astellas Prize in Public Health, 2008
  • Governor's Award for Research Impact, 2009

View Publications

  • Lin, WHW; Moran, E; Adams, RJ; Sievers, RE; Hauer, D; Godin, S; Griffin, DE. (Apr 2020). A durable protective immune response to wild-type measles virus infection of macaques is due to viral replication and spread in lymphoid tissues. SCIENCE TRANSLATIONAL MEDICINE , 12(537). 10.1126/scitranslmed.aax7799
  • Manion, JR, SP Cape, DH McAdams, LG Rebits, S Evans and RE Sievers. (2012). Inhalable Antibiotics Manufactured Through Use of Near-Critical or Supercritical Fluids. AEROSOL SCIENCE AND TECHNOLOGY, 46(4), 403-410. 10.1080/02786826.2011.634453
  • Lin, WH, DE Griffin, PA Rota, M Papania, SP Cape, D Bennett, B Quinn, RE Sievers, C Shermer, K Powell, RJ Adams, S Godin and S Winston. (15-Feb 2011). Successful respiratory immunization with dry powder live-attenuated measles virus vaccine in rhesus macaques. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 108(7), 2987-2992. 10.1073/pnas.1017334108
  • Kisich, KO, MP Higgins, I Park, SP Cape, L Lindsay, DJ Bennett, S Winston, J Searles and RE Sievers. (29-Jan 2011). Dry powder measles vaccine: Particle deposition, virus replication, and immune response in cotton rats following inhalation. VACCINE, 29(5), 905-912. 10.1016/j.vaccine.2010.10.020
  • Cape, SP, JA Villa, ETS Huang, TH Yang, JF Carpenter and RE Sievers. (SEP 2008). Preparation of Active Proteins, Vaccines and Pharmaceuticals as Fine Powders using Supercritical or Near-Critical Fluids. PHARMACEUTICAL RESEARCH, 25(9), 1967-1990. 10.1007/s11095-008-9575-6
  • Kissmann, J, SF Ausar, A Rudolph, C Braun, SP Cape, RE Sievers, MJ Federspiel, SB Joshi and CR Middaugh. (SEP-OCT 2008). Stabilization of measles virus for vaccine formulation. HUMAN VACCINES, 4(5), 350-359. 10.4161/hv.4.5.5863
  • Burger, JL, SP Cape, CS Braun, DH Mcadams, JA Best, P Bhagwat, P Pathak, LG Rebits and RE Sievers. (MAR 2008). Stabilizing formulations for inhalable powders of live-attenuated measles virus vaccine. JOURNAL OF AEROSOL MEDICINE AND PULMONARY DRUG DELIVERY, 21(1), 25-34. 10.1089/jamp.2007.0658
  • Rebits, LG, DJ Bennett, PA Bhagwat, A Morin and RE Sievers. (DEC 2007). Method for quantifying the sample collected by an Andersen Cascade Impactor using total organic carbon analysis. JOURNAL OF AEROSOL SCIENCE, 38(12), 1197-1206. 10.1016/j.jaerosci.2007.09.005
  • Villa, JA, ETS Huang, SP Cape and RE Sievers. (JUN 2005). Synthesis of composite microparticles with a mixing cross. AEROSOL SCIENCE AND TECHNOLOGY, 39(6), 473-484. 10.1080/027868290964432
  • Huang, ETS, H Chang, CD Liang and RE Sievers. (2003). Fine particle pharmaceutical manufacturing using dense carbon dioxide mixed with aqueous or alcoholic solutions. SUPERCRITICAL CARBON DIOXIDE: SEPARATIONS AND PROCESSES, 860, 324-338.
  • Sievers, RE, ETS Huang, JA Villa, G Engling and PR Brauer. (MAY 2003). Micronization of water-soluble or alcohol-soluble pharmaceuticals and model compounds with a low-temperature Bubble Dryer (R). JOURNAL OF SUPERCRITICAL FLUIDS, 26(1), 9-16. 10.1016/S0896-8446(02)00188-2
  • Andersen, WC, BC Noll, SP Sellers, LL Whildin and RE Sievers. (28-Jul 2002). Characterization and structures of the 2,2,7-trimethyl-3,5-octanedionate chelates of cerium(IV) and terbium(III). INORGANICA CHIMICA ACTA, 336, 105-110. 10.1016/S0020-1693(02)00873-3
  • Andersen, WC, RE Sievers, AF Lagalante and TJ Bruno. (SEP-OCT 2001). Solubilities of cerium(IV), terbium(III), and iron(III) ss-diketonates in supercritical carbon dioxide. JOURNAL OF CHEMICAL AND ENGINEERING DATA, 46(5), 1045-1049. 10.1021/je000257c
  • Sievers, RE, ETS Huang, JA Villa, JK Kawamoto, MM Evans and PR Brauer. (AUG 2001). Low-temperature manufacturing of fine pharmaceutical powders with supercritical fluid aerosolization in a Bubble Dryer (R). PURE AND APPLIED CHEMISTRY, 73(8), 1299-1303. 10.1351/pac200173081299
  • Sellers, SP, GS Clark, RE Sievers and JF Carpenter. (JUN 2001). Dry powders of stable protein formulations from aqueous solutions prepared using supercritical CO2-assisted aerosolization. JOURNAL OF PHARMACEUTICAL SCIENCES, 90(6), 785-797. 10.1002/jps.1032
  • Sievers, RE, PD Milewski, SP Sellers, BA Miles, BJ Korte, KD Kusek, GS Clark, B Mioskowski and JA Villa. (DEC 2000). Supercritical and near-critical carbon dioxide assisted low-temperature bubble drying. INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH, 39(12), 4831-4836. 10.1021/ie000190m
  • Sievers, RE, U Karst, PD Milewski, SP Sellers, BA Miles, JD Schaefer, CR Stoldt and CY Xu. (JAN 1999). Formation of aqueous small droplet aerosols assisted by supercritical carbon dioxide. AEROSOL SCIENCE AND TECHNOLOGY, 30(1), 3-15. 10.1080/713834046
  • Frazey, PA, RM Barkley and RE Sievers. (1-Feb 1998). Solid phase microextraction with temperature-programmed desorption for the analysis of iodination disinfection byproducts. ANALYTICAL CHEMISTRY, 70(3), 638-644. 10.1021/ac970395d
  • Xu, CY, BA Watkins, RE Sievers, XP Jing, P Trowga, CS Gibbons and A Vecht. (22-Sep 1997). Submicron-sited spherical yttrium oxide based phosphors prepared by supercritical CO2-assisted aerosolization and pyrolysis. APPLIED PHYSICS LETTERS, 71(12), 1643-1645. 10.1063/1.120004
  • Veltkamp, PR, KJ Hansen, RM Barkley and RE Sievers. (JUN 1996). Chromatographic measurement of molecular markers of sources of atmospheric aerosol particles. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH, 18(2), 77-80. 10.1007/BF01771135
  • Veltkamp, PR, KJ Hansen, RM Barkley and RE Sievers. (27-Aug 1996). Principal component analysis of summertime organic aerosols at Niwot Ridge, Colorado. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 101(D14), 19495-19504. 10.1029/95JD01749
  • LAGALANTE, AF, BN HANSEN, TJ BRUNO and RE SIEVERS. (8-Nov 1995). SOLUBILITIES OF COPPER(II) AND CHROMIUM(III) BETA-DIKETONATES IN SUPERCRITICAL CARBON-DIOXIDE. INORGANIC CHEMISTRY, 34(23), 5781-5785. 10.1021/ic00127a015
  • HANSEN, KJ, BN NANSEN, E CRAVENS and RE SIEVERS. (1-Oct 1995). SUPERCRITICAL-FLUID EXTRACTION GAS-CHROMATOGRAPHIC ANALYSIS OF ORGANIC-COMPOUNDS IN ATMOSPHERIC AEROSOLS. ANALYTICAL CHEMISTRY, 67(19), 3541-3549. 10.1021/ac00115a025
  • BUHR, SM, MP BUHR, FC FEHSENFELD, JS HOLLOWAY, U KARST, RB NORTON, DD PARRISH and RE SIEVERS. (OCT 1995). DEVELOPMENT OF A SEMICONTINUOUS METHOD FOR THE MEASUREMENT OF NITRIC-ACID VAPOR AND PARTICULATE NITRATE AND SULFATE. ATMOSPHERIC ENVIRONMENT, 29(19), 2609-2624. 10.1016/1352-2310(95)00171-T
  • DUNHAM, AJ, RM BARKLEY and RE SIEVERS. (1-Jan 1995). AQUEOUS NITRITE ION DETERMINATION BY SELECTIVE REDUCTION AND GAS-PHASE NITRIC-OXIDE CHEMILUMINESCENCE. ANALYTICAL CHEMISTRY, 67(1), 220-224. 10.1021/ac00097a033
  • HANSEN, BN, AF LAGALANTE, RE SIEVERS and TJ BRUNO. (JUN 1994). HIGH-PRESSURE EQUILIBRIUM CELL FOR SOLUBILITY MEASUREMENTS IN SUPERCRITICAL FLUIDS. REVIEW OF SCIENTIFIC INSTRUMENTS, 65(6), 2112-2114. 10.1063/1.1144821
  • HUANG, L, SB TURNIPSEED, RC HALTIWANGER, RM BARKLEY and RE SIEVERS. (16-Feb 1994). SYNTHESIS AND STRUCTURES OF VOLATILE MONONUCLEAR AND PENTANUCLEAR CHELATES OF BARIUM. INORGANIC CHEMISTRY, 33(4), 798-803. 10.1021/ic00082a029
  • RYERSON, TB, RM BARKLEY and RE SIEVERS. (3-Jun 1994). SELECTIVE CHEMILUMINESCENCE DETECTION OF SULFUR-CONTAINING-COMPOUNDS COUPLED WITH NITROGEN-PHOSPHORUS DETECTION FOR GAS-CHROMATOGRAPHY. JOURNAL OF CHROMATOGRAPHY A, 670(2-Jan), 117-126. 10.1016/0021-9673(94)80286-6
  • Hansen, Kris and Robert E. Sievers. (1994 1994). Incorporating undergraduates into graduate research in environmental science. Abstracts of Papers American Chemical Society, 207(2-Jan), 111-ANYL 111.
  • RYERSON, TB, AJ DUNHAM, RM BARKLEY and RE SIEVERS. (15-Sep 1994). SULFUR-SELECTIVE DETECTOR FOR LIQUID-CHROMATOGRAPHY BASED ON SULFUR MONOXIDE-OZONE CHEMILUMINESCENCE. ANALYTICAL CHEMISTRY, 66(18), 2841-2851. 10.1021/ac00090a009
  • HYBERTSON, BM, JE REPINE, CJ BEEHLER, KS RUTLEDGE, AF LAGALANTE and RE SIEVERS. (WIN 1993). PULMONARY DRUG-DELIVERY OF FINE AEROSOL-PARTICLES FROM SUPERCRITICAL FLUIDS. JOURNAL OF AEROSOL MEDICINE-DEPOSITION CLEARANCE AND EFFECTS IN THE LUNG, 6(4), 275-286. 10.1089/jam.1993.6.275
  • SIEVERS, RE, SB TURNIPSEED, L HUANG and AF LAGALANTE. (OCT 1993). VOLATILE BARIUM BETA-DIKETONATES FOR USE AS MOCVD PRECURSORS. COORDINATION CHEMISTRY REVIEWS, 128(2-Jan), 285-291. 10.1016/0010-8545(93)80035-4
  • BUHR, MP, M TRAINER, DD PARRISH, RE SIEVERS and FC FEHSENFELD. (22-May 1992). ASSESSMENT OF POLLUTANT EMISSION INVENTORIES BY PRINCIPAL COMPONENT ANALYSIS OF AMBIENT AIR MEASUREMENTS. GEOPHYSICAL RESEARCH LETTERS, 19(10), 1009-1012. 10.1029/92GL01020
  • BROOKS, KC, SB TURNIPSEED, RM BARKLEY, RE SIEVERS, V TULCHINSKY and AE KALOYEROS. (JUL-AUG 1992). SYNTHESIS AND CHARACTERIZATION OF VOLATILE BISMUTH BETA-DIKETONATE COMPOUNDS FOR METAL ORGANIC-CHEMICAL VAPOR-DEPOSITION OF THIN-FILMS. CHEMISTRY OF MATERIALS, 4(4), 912-916. 10.1021/cm00022a030
  • HANSEN, BN, BM HYBERTSON, RM BARKLEY and RE SIEVERS. (JUL-AUG 1992). SUPERCRITICAL FLUID TRANSPORT CHEMICAL-DEPOSITION OF FILMS. CHEMISTRY OF MATERIALS, 4(4), 749-752. 10.1021/cm00022a003
  • SIEVERS, RE and B HANSEN. (22-Jul 1991). CHEMICAL SAFETY - SUPERCRITICAL FLUID NITROUS-OXIDE EXPLOSION. CHEMICAL & ENGINEERING NEWS, 69(29), 2-2.
  • TURNIPSEED, SB, RM BARKLEY and RE SIEVERS. (20-Mar 1991). SYNTHESIS AND CHARACTERIZATION OF ALKALINE-EARTH-METAL BETA-DIKETONATE COMPLEXES USED AS PRECURSORS FOR CHEMICAL VAPOR-DEPOSITION OF THIN-FILM SUPERCONDUCTORS. INORGANIC CHEMISTRY, 30(6), 1164-1170. 10.1021/ic00006a003
  • MONTZKA, SA, BM HYBERTSON, RM BARKLEY and RE SIEVERS. (MAY 1991). LOW-TEMPERATURE OXIDATION OF YBA2CU3O6.0 WITH NITROGEN-DIOXIDE. JOURNAL OF MATERIALS RESEARCH, 6(5), 891-894. 10.1557/JMR.1991.0891
  • HYBERTSON, BM, BN HANSEN, RM BARKLEY and RE SIEVERS. (NOV 1991). DEPOSITION OF PALLADIUM FILMS BY A NOVEL SUPERCRITICAL FLUID TRANSPORT-CHEMICAL DEPOSITION PROCESS. MATERIALS RESEARCH BULLETIN, 26(11), 1127-1133. 10.1016/0025-5408(91)90118-6
  • BUHR, MP, DD PARRISH, RB NORTON, FC FEHSENFELD, RE SIEVERS and JM ROBERTS. (20-Jun 1990). CONTRIBUTION OF ORGANIC NITRATES TO THE TOTAL REACTIVE NITROGEN BUDGET AT A RURAL EASTERN UNITED-STATES SITE. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 95(D7), 9809-9816. 10.1029/JD095iD07p09809
  • DICKINSON, PH, TH GEBALLE, A SANJURJO, D HILDENBRAND, G CRAIG, M ZISK, J COLLMAN, SA BANNING and RE SIEVERS. (1-Jul 1989). CHEMICAL VAPOR-DEPOSITION OF YBA2CU3O7-X SUPERCONDUCTING FILMS. JOURNAL OF APPLIED PHYSICS, 66(1), 444-447. 10.1063/1.343845
  • FOREMAN, WT, CL SHELLUM, JW BIRKS and RE SIEVERS. (10-Mar 1989). SUPERCRITICAL FLUID CHROMATOGRAPHY WITH SULFUR CHEMI-LUMINESCENCE DETECTION. JOURNAL OF CHROMATOGRAPHY, 465(1), 23-33. 10.1016/S0021-9673(01)94939-8
  • MONTZKA, SA, RM BARKLEY and RE SIEVERS. (JUN 1989). CATALYZED REDOX REACTIONS OCCURRING IN A CHEMI-LUMINESCENCE DETECTOR USED FOR ENVIRONMENTAL-ANALYSIS. SOUTH AFRICAN JOURNAL OF CHEMISTRY, 42(2), 81-86.
  • FOREMAN, WT, RE SIEVERS and BW WENCLAWIAK. (1988). SUPERCRITICAL FLUID CHROMATOGRAPHY WITH REDOX CHEMI-LUMINESCENCE DETECTION. FRESENIUS ZEITSCHRIFT FUR ANALYTISCHE CHEMIE, 330(3), 231-234. 10.1007/BF00515613
  • DEANGELIS, JJ, RM BARKLEY and RE SIEVERS. (27-May 1988). COUPLING LIQUID-CHROMATOGRAPHY WITH REDOX CHEMI-LUMINESCENCE DETECTION. JOURNAL OF CHROMATOGRAPHY, 441(1), 125-134. 10.1016/S0021-9673(01)84660-4
  • MCNAMARA, EA, SA MONTZKA, RM BARKLEY and RE SIEVERS. (28-Oct 1988). SUPERCONDUCTOR METAL-OXIDE CATALYST IN A CHEMI-LUMINESCENCE CHROMATOGRAPHY DETECTOR. JOURNAL OF CHROMATOGRAPHY, 452, 75-83. 10.1016/S0021-9673(01)81438-2
  • SIEVERS, RE, RL SHEARER and RM BARKLEY. (12-Jun 1987). GAS-CHROMATOGRAPHIC MEASUREMENT OF CARBON-MONOXIDE IN HYDROCARBON MATRICES WITH A REDOX CHEMILUMINESCENCE DETECTOR. JOURNAL OF CHROMATOGRAPHY, 395, 9-17. 10.1016/S0021-9673(01)94096-8
  • POURREZA, N, SA MONTZKA, RM BARKLEY, RE SIEVERS and RS HUTTE. (24-Jul 1987). CHEMISTRY OCCURRING IN REDOX CHEMILUMINESCENCE DETECTORS FOR CHROMATOGRAPHY. JOURNAL OF CHROMATOGRAPHY, 399, 165-172.
  • GREAVES, RC, RM BARKLEY, RE SIEVERS and RR MEGLEN. (1987). COVARIATIONS IN THE CONCENTRATIONS OF ORGANIC-COMPOUNDS ASSOCIATED WITH SPRINGTIME ATMOSPHERIC AEROSOLS. ATMOSPHERIC ENVIRONMENT, 21(12), 2549-2561. 10.1016/0004-6981(87)90187-9
  • HUTTE, RS, RE SIEVERS and JW BIRKS. (NOV 1986). GAS-CHROMATOGRAPHY DETECTORS BASED ON CHEMILUMINESCENCE. JOURNAL OF CHROMATOGRAPHIC SCIENCE, 24(11), 499-505. 10.1093/chromsci/24.11.499
  • ROBERTS, JM, CJ HAHN, FC FEHSENFELD, JM WARNOCK, DL ALBRITTON and RE SIEVERS. (1985). MONOTERPENE HYDROCARBONS IN THE NIGHTTIME TROPOSPHERE. ENVIRONMENTAL SCIENCE & TECHNOLOGY, 19(4), 364-369. 10.1021/es00134a011
  • GRADEFF, PS, FG SCHREIBER, KC BROOKS and RE SIEVERS. (1985). SIMPLIFIED METHOD FOR THE SYNTHESIS OF CERIC ALKOXIDES FROM CERIC AMMONIUM-NITRATE. INORGANIC CHEMISTRY, 24(7), 1110-1111. 10.1021/ic00201a033
  • WENZEL, TJ, EJ WILLIAMS, RC HALTIWANGER and RE SIEVERS. (1985). STUDIES OF METAL-CHELATES WITH THE NOVEL LIGAND 2,2,7-TRIMETHYL-3,5-OCTANEDIONE. POLYHEDRON, 4(3), 369-378. 10.1016/S0277-5387(00)86994-6
  • NYARADY, SA and RE SIEVERS. (1985). SELECTIVE CATALYTIC-OXIDATION OF ORGANIC-COMPOUNDS BY NITROGEN-DIOXIDE. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 107(12), 3726-3727. 10.1021/ja00298a058
  • GILLIS, JN, RE SIEVERS and GE POLLOCK. (1985). SELECTIVE RETENTION OF OXYGEN USING CHROMATOGRAPHIC COLUMNS CONTAINING METAL CHELATE POLYMERS. ANALYTICAL CHEMISTRY, 57(8), 1572-1577. 10.1021/ac00285a017
  • NYARADY, SA, RM BARKLEY and RE SIEVERS. (1985). REDOX CHEMI-LUMINESCENCE DETECTOR - APPLICATION TO GAS-CHROMATOGRAPHY. ANALYTICAL CHEMISTRY, 57(11), 2074-2079. 10.1021/ac00288a016
  • HAWTHORNE, SB, RE SIEVERS and RM BARKLEY. (1985). ORGANIC EMISSIONS FROM SHALE OIL WASTEWATERS AND THEIR IMPLICATIONS FOR AIR-QUALITY. ENVIRONMENTAL SCIENCE & TECHNOLOGY, 19(10), 992-997. 10.1021/es00140a018
  • ROBERTS, JM, RS HUTTE, FC FEHSENFELD, DL ALBRITTON and RE SIEVERS. (1985). MEASUREMENTS OF ANTHROPOGENIC HYDROCARBON CONCENTRATION RATIOS IN THE RURAL TROPOSPHERE - DISCRIMINATION BETWEEN BACKGROUND AND URBAN SOURCES. ATMOSPHERIC ENVIRONMENT, 19(11), 1945-1950. 10.1016/0004-6981(85)90020-4
  • GREAVES, RC, RM BARKLEY and RE SIEVERS. (1985). RAPID SAMPLING AND ANALYSIS OF VOLATILE CONSTITUENTS OF AIRBORNE PARTICULATE MATTER. ANALYTICAL CHEMISTRY, 57(14), 2807-2815. 10.1021/ac00291a015
  • WENCLAWIAK, B, RM BARKLEY, EJ WILLIAMS and RE SIEVERS. (11-Dec 1985). GAS-CHROMATOGRAPHIC AND LIQUID-CHROMATOGRAPHIC SEPARATIONS OF GEOMETRICAL-ISOMERS OF TRIS(2,2,7-TRIMETHYLOCTANE-3,5-DIONATO)CHROMIUM(III) AND COBALT(III) CHELATES AND OTHER CR-BETA-DIKETONATES. JOURNAL OF CHROMATOGRAPHY, 349(2), 469-479. 10.1016/S0021-9673(01)83807-3
  • SIEVERS, RE, SA NYARADY, RL SHEARER, JJ DEANGELIS, RM BARKLEY and RS HUTTE. (11-Dec 1985). SELECTIVITY OF THE REDOX CHEMILUMINESCENCE DETECTOR FOR COMPLEX SAMPLE ANALYSIS. JOURNAL OF CHROMATOGRAPHY, 349(2), 395-403. 10.1016/S0021-9673(01)83797-3
  • HAWTHORNE, SB and RE SIEVERS. (1984). EMISSION OF ORGANIC AIR-POLLUTANTS FROM SHALE OIL WASTEWATERS. ENVIRONMENTAL SCIENCE & TECHNOLOGY, 18(6), 483-490. 10.1021/es00124a016
  • CONDITT, MK and RE SIEVERS. (1984). MICROANALYSIS OF REACTION-PRODUCTS IN SEALED TUBE WET AIR OXIDATIONS BY CAPILLARY GAS-CHROMATOGRAPHY. ANALYTICAL CHEMISTRY, 56(13), 2620-2622. 10.1021/ac00277a085
  • WILLIAMS, EJ and RE SIEVERS. (1984). SYNTHESIS AND CHARACTERIZATION OF A NEW SORBENT FOR USE IN THE DETERMINATION OF VOLATILE, COMPLEX-FORMING ORGANIC-COMPOUNDS IN AIR. ANALYTICAL CHEMISTRY, 56(13), 2523-2528. 10.1021/ac00277a058
  • HUTTE, RS, EJ WILLIAMS, J STAEHELIN, SB HAWTHORNE, RM BARKLEY and RE SIEVERS. (1984). CHROMATOGRAPHIC ANALYSIS OF ORGANIC-COMPOUNDS IN THE ATMOSPHERE. JOURNAL OF CHROMATOGRAPHY, 302(OCT), 173-179. 10.1016/S0021-9673(01)89009-9
  • ROBERTS, JM, FC FEHSENFELD, SC LIU, MJ BOLLINGER, C HAHN, DL ALBRITTON and RE SIEVERS. (1984). MEASUREMENTS OF AROMATIC HYDROCARBON RATIOS AND NOX CONCENTRATIONS IN THE RURAL TROPOSPHERE - OBSERVATION OF AIR-MASS PHOTOCHEMICAL AGING AND NOX REMOVAL. ATMOSPHERIC ENVIRONMENT, 18(11), 2421-2432. 10.1016/0004-6981(84)90012-X
  • WENCLAWIAK, B and RE SIEVERS. (1983). SEPARATION OF GEOMETRICAL-ISOMERS OF CR-BETA-DIKETONATES WITH REVERSED PHASE-HPLC. FRESENIUS ZEITSCHRIFT FUR ANALYTISCHE CHEMIE, 314(7), 682-682. 10.1007/BF00487359
  • SIEVERS, RE and KC BROOKS. (1983). GAS-CHROMATOGRAPHY COMBINED WITH MASS-SPECTROMETRY IN STUDIES OF COMPLEX-MIXTURES OF TRIS(BETA-DIKETONATO)CHROMIUM(III) GEOMETRICAL-ISOMERS WITH FUSED-SILICA CAPILLARY COLUMNS. INTERNATIONAL JOURNAL OF MASS SPECTROMETRY AND ION PROCESSES, 47(JAN), 527-530. 10.1016/0020-7381(83)87250-7
  • BOLLINGER, MJ, RE SIEVERS, DW FAHEY and FC FEHSENFELD. (1983). CONVERSION OF NITROGEN-DIOXIDE, NITRIC-ACID, AND NORMAL-PROPYL NITRATE TO NITRIC-OXIDE BY GOLD-CATALYZED REDUCTION WITH CARBON-MONOXIDE. ANALYTICAL CHEMISTRY, 55(12), 1980-1986. 10.1021/ac00262a034
  • ROBERTS, JM, FC FEHSENFELD, DL ALBRITTON and RE SIEVERS. (1983). MEASUREMENT OF MONOTERPENE HYDROCARBONS AT NIWOT RIDGE, COLORADO. JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS, 88(NC15), 667-678. 10.1029/JC088iC15p10667
  • WENZEL, TJ and RE SIEVERS. (1982). NUCLEAR MAGNETIC-RESONANCE STUDIES OF TERPENES WITH CHIRAL AND ACHIRAL LANTHANIDE(III) SILVER(I) BINUCLEAR SHIFT-REAGENTS. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 104(2), 382-388. 10.1021/ja00366a003
  • WENZEL, TJ, ME ASHLEY and RE SIEVERS. (1982). WATER-SOLUBLE PARAMAGNETIC RELAXATION REAGENTS FOR C-13 NUCLEAR MAGNETIC-RESONANCE SPECTROMETRY. ANALYTICAL CHEMISTRY, 54(4), 615-621. 10.1021/ac00241a004
  • WIZNER, MA, S SINGHAWANGCHA, RM BARKLEY and RE SIEVERS. (1982). SELECTIVE ELECTRON-CAPTURE SENSITIZATION OF WATER, PHENOLS, AMINES AND AROMATIC AND HETEROCYCLIC-COMPOUNDS. JOURNAL OF CHROMATOGRAPHY, 239(APR), 145-157. 10.1016/S0021-9673(00)81976-7
  • WENZEL, TJ and RE SIEVERS. (1982). BINUCLEAR SHIFT-REAGENTS FOR NUCLEAR MAGNETIC-RESONANCE SPECTROMETRY OF AROMATIC AND POLYCYCLIC AROMATIC-COMPOUNDS. ANALYTICAL CHEMISTRY, 54(9), 1602-1606. 10.1021/ac00246a032
  • PICKER, JE and RE SIEVERS. (1981). LANTHANIDE METAL-CHELATES AS SELECTIVE COMPLEXING SORBENTS FOR GAS-CHROMATOGRAPHY. JOURNAL OF CHROMATOGRAPHY, 203(JAN), 29-40. 10.1016/S0021-9673(00)80279-4
  • WENZEL, TJ and RE SIEVERS. (1981). BINUCLEAR COMPLEXES OF LANTHANIDE(III) AND SILVER(I) AND THEIR FUNCTION AS SHIFT-REAGENTS FOR OLEFINS, AROMATICS, AND HALOGENATED COMPOUNDS. ANALYTICAL CHEMISTRY, 53(3), 393-399. 10.1021/ac00226a005
  • PICKER, JE and RE SIEVERS. (1981). APPLICATIONS OF SELECTIVE COMPLEXATION BY A EUROPIUM(III) COORDINATION POLYMER SORBENT FOR THE PRE-FRACTIONATION OF VOLATILE COMPOUNDS. JOURNAL OF CHROMATOGRAPHY, 217(NOV), 275-288. 10.1016/S0021-9673(00)88082-6
  • CUNNINGHAM, JA and RE SIEVERS. (1980). STRUCTURES OF EUROPIUM COMPLEXES AND IMPLICATIONS IN LANTHANIDE NUCLEAR MAGNETIC-RESONANCE SHIFT-REAGENT CHEMISTRY. INORGANIC CHEMISTRY, 19(3), 595-604. 10.1021/ic50205a005
  • WENZEL, TJ, TC BETTES, JE SADLOWSKI and RE SIEVERS. (1980). NEW BINUCLEAR LANTHANIDE NMR SHIFT-REAGENTS EFFECTIVE FOR AROMATIC-COMPOUNDS. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 102(18), 5903-5904. 10.1021/ja00538a032
  • GOLDAN, PD, FC FEHSENFELD, WC KUSTER, MP PHILLIPS and RE SIEVERS. (1980). VINYL-CHLORIDE DETECTION AT SUB-PARTS-PER-BILLION LEVELS WITH A CHEMICALLY SENSITIZED ELECTRON-CAPTURE DETECTOR. ANALYTICAL CHEMISTRY, 52(11), 1751-1754. 10.1021/ac50061a048
  • HALTIWANGER, RC, KJ KOLONKO, RH SHAPIRO and RE SIEVERS. (1979). 1,4,5,6-TETRAHYDRO-1,5,N-TRIMETHYL-4,6-DIOXO-1,3,5-TRIAZINE-2-CARBOXAMIDE. ACTA CRYSTALLOGRAPHICA SECTION B-STRUCTURAL SCIENCE, 35(JUN), 1509-1512. 10.1107/S0567740879006919
  • PHILLIPS, MP, RE SIEVERS, PD GOLDAN, WC KUSTER and FC FEHSENFELD. (1979). ENHANCEMENT OF ELECTRON-CAPTURE DETECTOR SENSITIVITY TO NONELECTRON ATTACHING COMPOUNDS BY ADDITION OF NITROUS-OXIDE TO THE CARRIER GAS. ANALYTICAL CHEMISTRY, 51(11), 1819-1825. 10.1021/ac50047a049
  • KOLONKO, KJ, RH SHAPIRO, RM BARKLEY and RE SIEVERS. (1979). OZONATION OF CAFFEINE IN AQUEOUS-SOLUTION. JOURNAL OF ORGANIC CHEMISTRY, 44(22), 3769-3778. 10.1021/jo01336a007
  • SIEVERS, RE, MP PHILLIPS, RM BARKLEY, MA WIZNER, MJ BOLLINGER, RS HUTTE and FC FEHSENFELD. (1979). SELECTIVE ELECTRON-CAPTURE SENSITIZATION. JOURNAL OF CHROMATOGRAPHY, 186(DEC), 3-14. 10.1016/S0021-9673(00)95232-4
  • SIEVERS, RE and JE SADLOWSKI. (1978). VOLATILE METAL-COMPLEXES. SCIENCE, 201(4352), 217-223. 10.1126/science.201.4352.217
  • PETERSON, H, GA EICEMAN, RE SIEVERS and LR FIELD. (1978). GAS-CHROMATOGRAPHIC INJECTOR ATTACHMENT FOR DIRECT INSERTION AND REMOVAL OF A POROUS POLYMER SORPTION TRAP. ANALYTICAL CHEMISTRY, 50(14), 2152-2154. 10.1021/ac50036a052
  • CHEN, TM, GG HESS and RE SIEVERS. (1977). IMPROVEMENTS IN GAS-CHROMATOGRAPHIC COLUMNS FORMED BY INSITU POLYMERIZATION. JOURNAL OF CHROMATOGRAPHY, 134(1), 170-173. 10.1016/S0021-9673(00)82580-7
  • ROSS, WD, JL PYLE and RE SIEVERS. (1977). ANALYSIS FOR BERYLLIUM IN AMBIENT AIR PARTICULATES BY GAS-CHROMATOGRAPHY. ENVIRONMENTAL SCIENCE & TECHNOLOGY, 11(5), 467-471. 10.1021/es60128a004
  • BLACK, MS, WR REHG, RE SIEVERS and JJ BROOKS. (1977). GAS-CHROMATOGRAPHIC TECHNIQUE FOR COMPOUND CLASS ANALYSIS OF JET ENGINE EXHAUST. JOURNAL OF CHROMATOGRAPHY, 142(NOV), 809-822. 10.1016/S0021-9673(01)92088-6
  • SIEVERS, RE, RM BARKLEY, GA EICEMAN, RH SHAPIRO, HF WALTON, KJ KOLONKO and LR FIELD. (1977). ENVIRONMENTAL TRACE ANALYSIS OF ORGANICS IN WATER BY GLASS CAPILLARY COLUMN CHROMATOGRAPHY AND ANCILLARY TECHNIQUES - PRODUCTS OF OZONOLYSIS. JOURNAL OF CHROMATOGRAPHY, 142(NOV), 745-754. 10.1016/S0021-9673(01)92082-5
  • NAVRATIL, JD, RE SIEVERS and HF WALTON. (1977). OPEN-PORE POLYURETHANE COLUMNS FOR COLLECTION AND PRECONCENTRATION OF POLYNUCLEAR AROMATIC-HYDROCARBONS FROM WATER. ANALYTICAL CHEMISTRY, 49(14), 2260-2263. 10.1021/ac50022a038
  • NAVRATIL, JD and RE SIEVERS. (1977). CHEMICAL SEPARATIONS WITH OPEN-PORE POLYURETHANE. INT LAB(NOV-), 26-&.
  • SIEVERS, RE, JJ BROOKS, JA CUNNINGHAM and WE RHINE. (1976). UNUSUALLY VOLATILE AND SOLUBLE METAL-CHELATES - LANTHANIDE NMR SHIFT-REAGENTS. ADVAN CHEM SER(150), 222-231.
  • BLACK, MS and RE SIEVERS. (1976). DETERMINATION OF CHROMIUM IN HUMAN-BLOOD SERUM BY GAS-CHROMATOGRAPHY WITH A MICROWAVE EXCITED EMISSION DETECTOR. ANALYTICAL CHEMISTRY, 48(13), 1872-1874. 10.1021/ac50007a015
  • TESCH, JW, WR REHG and RE SIEVERS. (1976). MICRODETERMINATION OF NITRATES AND NITRITES IN SALIVA, BLOOD, WATER, AND SUSPENDED PARTICULATES IN AIR BY GAS-CHROMATOGRAPHY. JOURNAL OF CHROMATOGRAPHY, 126(3-Nov), 743-755. 10.1016/S0021-9673(01)84117-0
  • ROSS, WD, GW BUTTLER, TG DUFFY, WR REHG, MT WININGER and RE SIEVERS. (1975). ANALYSIS FOR AQUEOUS NITRATES AND NITRITES AND GASEOUS OXIDES OF NITROGEN BY ELECTRON-CAPTURE GAS-CHROMATOGRAPHY. J CHROMATOGR, 112(29-Oct), 719-727.
  • KUTAL, C and RE SIEVERS. (1974). RATE AND EQUILIBRIUM STUDY OF CIS-TRANS ISOMERIZATION OF TRIS(1,1,1-TRIFLUORO-2,4-PENTANEDIONATO)CHROMIUM(III) IN GAS-PHASE. Inorg. Chem., 13(4), 897-900.
  • HANSEN, LC and RE SIEVERS. (1974). HIGHLY PERMEABLE OPEN-PORE POLYURETHANE COLUMNS FOR LIQUID-CHROMATOGRAPHY. J CHROMATOGR, 99(6-Nov), 123-133.
  • HILEMAN, FD, RE SIEVERS, GG HESS and WD ROSS. (1973). IN-SITU PREPARATION AND EVALUATION OF OPEN PORE POLYURETHANE CHROMATOGRAPHIC COLUMNS. Anal. Chem., 45(7), 1126-1130.
  • BROOKS, JJ and RE SIEVERS. (1973). GAS-CHROMATOGRAPHIC STUDIES OF INTERACTIONS BETWEEN SELECTED ORGANIC NUCLEOPHILES AND NMR SHIFT REAGENT, TRIS(1,1,1,2,2,3,3-HEPTAFLUORO-7,7-DIMETHYL-4,6-OCTANEDIONATO)EUROPIUM(III). J. Chromatogr. Sci., 11(6), 303-309.
  • ECKSTEIN, H, RE SIEVERS and E BAYER. (1973). SIMPLIFIED SYNTHESIS OF TYROSINE AND LYSINE DERIVATIVES FROM THEIR COPPER-COMPLEXES BY LIGAND-EXCHANGE WITH DISODIUM SALT OF ETHYLENEDIAMINETETRAACETIC ACID (EDTA). ANN CHEM(9), 1467-1470.
  • BAYER, E, M MUTTER, RE SIEVERS, R UHMANN and P HUNZIKER. (1972). F-19 NUCLEAR MAGNETIC-RESONANCE FOR CONTROL OF PEPTIDE SYNTHESIS. J. Am. Chem. Soc., 94(1), 265-&.
  • ROSS, WD and RE SIEVERS. (1972). ENVIRONMENTAL AIR ANALYSIS FOR ULTRATRACE CONCENTRATIONS OF BERYLLIUM BY GAS-CHROMATOGRAPHY. Environ. Sci. Technol., 6(2), 155-&.
  • RICHARDS.MF and RE SIEVERS. (1972). CRYSTAL AND MOLECULAR STRUCTURE OF MACROCYCLIC COMPLEX, 11,13-DIMETHYL-1,4,7,10-TETRAAZACYCLOTRIDECA-10,12-DIENATONICKEL(II) PERCHLORATE. J. Am. Chem. Soc., 94(12), 4134-&.
  • CUMMINGS, SC and RE SIEVERS. (1972). PSEUDOOCTAHEDRAL COBALT(III), NICKEL(II), AND CADMIUM(II) COMPLEXES OF LINEAR, SEXADENTATE, FLUORINATED SCHIFF-BASE LIGANDS. Inorg. Chem., 11(7), 1483-&.
  • EISENTRA.KJ, RE SIEVERS, MS BLACK and DJ GRIEST. (1972). BERYLLIUM CONTENT OF US GEOLOGICAL SURVEY STANDARD ROCKS. Earth Planet. Sci. Lett., 15(2), 169-&.
  • WOLF, WR, RE SIEVERS and GH BROWN. (1972). VAPOR-PRESSURE MEASUREMENTS AND GAS-CHROMATOGRAPHIC STUDIES OF SOLUTION THERMODYNAMICS OF METAL BETA-DIKETONATES. Inorg. Chem., 11(9), 1995-&.
  • FEIBUSH, B, RE SIEVERS, CS SPRINGER and RICHARDS.MF. (1972). COMPLEXES OF NUCLEOPHILES WITH RARE-EARTH CHELATES .1. GAS-CHROMATOGRAPHIC STUDIES OF LANTHANIDE NUCLEAR MAGNETIC-RESONANCE SHIFT REAGENTS. J. Am. Chem. Soc., 94(19), 6717-&.
  • HANSEN, LC, WG SCRIBNER, TW GILBERT and RE SIEVERS. (1971). RAPID ANALYSIS FOR SUB-NANOGRAM AMOUNTS OF CHROMIUM IN BLOOD AND PLASMA USING ELECTRON CAPTURE GAS CHROMATOGRAPHY. Anal. Chem., 43(3), 349-&.
  • RICHARDS.MF and RE SIEVERS. (1971). VOLATILE RARE EARTH CHELATES OF 1,1,1,5,5,5-HEXAFLUORO-2,4-PENTANEDIONE AND 1,1,1,2,2,3,3,7,7,7-DECAFLUORO-4,6-HEPTANEDIONE. Inorg. Chem., 10(3), 498-&.
  • RONDEAU, RE and RE SIEVERS. (1971). NEW SUPERIOR PARAMAGNETIC SHIFT REAGENTS FOR NUCLEAR MAGNETIC RESONANCE SPECTRAL CLARIFICATION. J. Am. Chem. Soc., 93(6), 1522-&.
  • SPRINGER, C, RE SIEVERS and B FEIBUSH. (1971). CHIRAL CHELATES WITH CHIRAL LIGANDS - STEREOISOMERS OF TRIS[(+]-3-ACETYLCAMPHORATO(COBALT(III). Inorg. Chem., 10(6), 1242-&.
  • BAYER, E, HP MULLER and R SIEVERS. (1971). HEXAFLUOROMONOTHIOACETYLACETONE-A NEW LIGAND FOR GAS CHROMATOGRAPHIC SEPARATION OF D8-METALS. Anal. Chem., 43(14), 2012-&.
  • EISENTRA.KJ, DJ GRIEST and RE SIEVERS. (1971). ULTRATRACE ANALYSIS FOR BERYLLIUM IN TERRESTRIAL, METEORITIC, AND APOLLO-11 AND APOLLO-12 LUNAR SAMPLES USING ELECTRON CAPTURE GAS CHROMMATOGRAPHY. Anal. Chem., 43(14), 2003-&.
  • CUMMINGS, SC and RE SIEVERS. (1970). A NEW SYNTHETIC ROUTE TO MACROCYCLIC NICKEL(II) COMPLEXES WITH UNINEGATIVE, SCHIFF-BASE LIGANDS. Inorg. Chem., 9(5), 1131-&.
  • RICHARDS.MF and RE SIEVERS. (1970). SCHIFF BASES PREPARED FROM ETHYLENEDIAMINE AND HEXAFLUOROACETYLACETONE. J INORG NUCL CHEM, 32(6), 1895-&.
  • RICHARDS.MF, PW CORFIELD, DE SANDS and RE SIEVERS. (1970). CRYSTAL AND MOLECULAR STRUCTURE OF ACETYLACETONIMINE ADDUCT OF YTTERBIUM ACETYLACETONATE, YB(C5H7O2)3(CH3COCH=C(NH2)CH3). Inorg. Chem., 9(7), 1632-&.
  • BAYER, E, NICHOLSO.G and RE SIEVERS. (1970). SEPARATION OF ISOTOPES OF CARBON AND SULFUR BY GAS CHROMATOGRAPHY WITH PACKED COLUMNS. J. Chromatogr. Sci., 8(8), 467-&.
  • CUMMINGS, SC and RE SIEVERS. (1970). A NEW AND SIMPLE TEMPLATE SYNTHESIS OF UNINEGATIVE, MACROCYCLIC, CORRIN-TYPE LIGANDS. J. Am. Chem. Soc., 92(1), 215-&.
  • SICRE, JE, JT DUBOIS, EISENTRA.KJ and RE SIEVERS. (1969). VOLATILE LANTHANIDE CHELATES .2. VAPOR PRESSURES HEATS OF VAPORIZATION AND HEATS OF SUBLIMATION. J. Am. Chem. Soc., 91(13), 3476-&.
  • KOWALSKI, BR, TL ISENHOUR and RE SIEVERS. (1969). ULTRA-TRACE MASS SPECTROMETRIC METAL ANALYSIS USING HEPTAFLUORODIMETHYLOCTANEDIONE CHELATES. Anal. Chem., 41(8), 998-&.
  • ROSS, WD and RE SIEVERS. (1968). RAPID ULTRA-TRACE DETERMINATION OF BERYLLIUM BY GAS CHROMATOGRAPHY. Talanta, 15(1), 87-&.
  • SIEVERS, RE, JW CONNOLLY and WD ROSS. (1967). METAL ANALYSIS BY GAS CHROMATOGRAPHY OF CHELATES OF HEPTAFLUORODIMETHYLOCTANEDIONE. J GAS CHROMATOGR, 5(5), 241-&.
  • SPRINGER, CS, DW MEEK and RE SIEVERS. (1967). RARE EARTH CHELATES OF 1,1,1,2,2,3,3-HEPTAFLUORO-7,7-DIMETHYL-4,6-OCTANEDIONE. Inorg. Chem., 6(6), 1105-&.
  • EISENTRA.KJ and RE SIEVERS. (1967). THERMOGRAVIMETRIC STUDIES OF METAL BETA-DIKETONATES. J INORG NUCL CHEM, 29(8), 1931-&.
  • FORTMAN, JJ and RE SIEVERS. (1967). DETERMINATION OF RATES OF OPTICAL INVERSION OF ALUMINUM BETA-DIKETONATE COMPLEXES BY NUCLEAR MAGNETIC RESONANCE STUDIES OF RACEMIC MIXTURES. Inorg. Chem., 6(11), 2022-&.
  • LINCK, RG and RE SIEVERS. (1966). SOLVENT EFFECTS ON NUCLEAR MAGNETIC RESONANCE SPECTRA OF ALUMINUM BETA-DIKETONATES. Inorg. Chem., 5(5), 806-&.
  • CHATTORA.SC, AG CUPKA and RE SIEVERS. (1966). CADMIUM AND ZINC CHELATES OF HEXAFLUOROACETYLACETONE - GAS PHASE REACTION OF A NOVEL VOLATILE CADMIUM COMPLEX WITH HYDROGEN SULPHIDE. J INORG NUCL CHEM, 28(9), 1937-&.
  • VANHEMER.RL, SPENDLOV.LB and RE SIEVERS. (1965). VAPOR DEPOSITION OF METALS BY HYDROGEN REDUCTION OF METAL CHELATES. J. Electrochem. Soc., 112(11), 1123-&.
  • DASSARMA, B, RE SIEVERS, JC BAILAR and KR RAY. (1964). STEREOCHEMISTRY OF METAL CHELATES WITH MULTIDENTATE LIGANDS .2. J. Am. Chem. Soc., 86(1), 14-&.
  • SIEVERS, RE, BW PONDER, ML MORRIS and RW MOSHIER. (1963). GAS PHASE CHROMATOGRAPHY OF METAL CHELATES OF ACETYLACETONE, TRIFLUOROACETYLACETONE, AND HEXAFLUOROACETYLACETONE. Inorg. Chem., 2(4), 693-&.
  • SIEVERS, RE and JC BAILAR. (1962). SOME METAL CHELATES OF ETHYLENEDIAMINETETRAACETIC ACID, DIETHYLENETRIAMINEPENTAACETIC ACID, AND TRIETHYLENETETRAMINEHEXAACETIC ACID. Inorg. Chem., 1(1), 174-&.