UPCOMING RESEARCH Optical Measurements of pH Using Fluorescence Lifetimes and Phase-Modulation Fluorometry A simple green H e - N e light source can be used to mea s u r e p H b y p h a s e - m o d u l a t i o n fluorometry. Lifetime measurements are advantageous in t h a t they can be in sensitive to photo-bleaching and/or probe washout. Such lifetime-based sensing can be expected to migrate r a p idly to the clinical environment for applications such as optical sensing of blood gases. Henryk Szmacinski and Joseph R. Lakowicz*, Department of Biological Chemistry, Center for Fluorescence Spectroscopy, University of Maryland School of Medicine, 660 West Redwood Street, Baltimore, MD 21201 Determination of Mercury at Electrodes Modified with Polymeric Films of [Ru(v-bpy) 3 ] 2+ Incorporating Amino Acids Electrodes t h a t have been modified with polymeric films of [Ru(v-bpy) 3 ] 2+ incorporting amino acids are employed for the determination of Hg in solution over the range of 1 χ 10" 7 -1 χ 1(T 2 M with an RSD of 5-10%. The relative sensitivity of the various ligands follows trends in t h e value of t h e formation c o n s t a n t s a n d can be used i n Hg speciation. Seong K. Cha*, Byung K. Ahn, Jung-Ui Hwang, and Hec tor D. Abruna*, Department of Chemistry, Kyungnam Uni versity, Masan, 630-701 Korea and Department of Chemistry, Cornell University, Ithaca, NY 14853-1301 Effects of High-Intensity Ultrasound on Glassy Carbon Electrodes Sonication of glassy carbon electrodes in dioxane results in surface activation effects t h a t persist for u p to five days. Analogous results a r e not obtained if ultrasonic modification is performed in water. Honghua Zhang and Louis A. Coury, Jr.*, Department of Chemistry, Duke University, Durham, NC 27708-0346 Neutral Products Formed during Backbone Fragmentation of Protonated Peptides in Tandem Mass Spectrometry Neutralization-reionization MS is used to characterize the neutral molecules eliminated upon the dissociation of protonated peptides. Identification of these complemen t a r y n e u t r a l losses reveals new structural information a n d m e c h a n i s t i c i n s i g h t into t h e f r a g m e n t a t i o n p r o cesses. Marcela M. Cordero, John J. Houser, and Chrys Wesdemiotis*, Department of Chemistry, The University of Akron, Ak ron, OH 44325-3601
These articles are scheduled to appear in AC RESEARCH in the n e a r future.
Ion Mobility Spectrometry of Hydrazine, Monomethylhydrazine, and Ammonia in Air with 5-Nonanone Reagent Gas A hand-held ion mobility spectrometer is configured with ionization chemistry to provide low-ppb-level detection limits for hydrazine and monomethylhydrazine without interference from ammonia. Calibration stability is dem onstrated during a period of six weeks, including use on the space shuttle Atlantis. Gary A. Eiceman*, Michael R. Salazar, and Michael R. Rod riguez, Department of Chemistry, New Mexico State Univer sity, Las Cruces, NM 88003-0001, Thomas F. Limero, Steve W. Beck, and John H. Cross, KRUG Life Sciences, Inc., Hous ton, TX 77058, Rebbeca Young, Toxic Vapor Detection Labora tory, National Aeronautical and Space Administration, John F. Kennedy Space Center, FL 32899, and John T. James, Bio medical Operations and Research Branch, National Aeronauti cal and Space Administration, Johnson Space Center, Houston, TX 77058 Selective Application of Chemical Separations to Isotope Dilution Inductively Coupled Plasma Mass Spectrometric Analyses of Standard Reference Materials The accuracy and precision of isotope dilution ICPMS can be degraded a s a result of matrix interferences. Cus tomized separations are developed, resulting in the certi fication of Ni, Cd, Mo, and Ag in five new environmental SRMs to precisions < 1%. E. S. Beary* and P. J. Paulsen, National Institute of Stan dards and Technology, Gaithersburg, MD 20899 Automated Determination of Iron in Seawater by Chelating Resin Concentration and Chemiluminescence Detection The method is based on a combination of selective col u m n extraction using 8-quinolinol chelating resin and improved luminol—hydrogen peroxide chemiluminescence detection in a closed, flow-through system. Hajime Obata, Department of Chemistry, Faculty of Science, Kyoto University, Kyoto 606-01, Japan, Hajime Karatani, De partment of Polymer Science and Engineering, Kyoto Institute of Technology, Kyoto 606, Japan, and Eiichiro Nakayama*, Research Center for Instrumental Analysis, Faculty of Science, Kyoto University, Kyoto 606-01, Japan Simultaneous Characterization of Extraction Equilibria and Back-Extraction Kinetics: Use of Arsenazo(lll) To Characterize Lanthanide-Bis(2,4,4-trimethylpentyl)phosphinic Acid Complexes in Surfactant Micelles A novel metallochromic indicator method is developed and applied using arsenazo(III) to simultaneously char acterize the extraction equilibria and dissociation kinet ics of lanthanide-dialkylphosphinic acid complexes in Triton X-100 micelles. Kazuho Inaba, Subramaniam Muralidharan*, and Henry Freiser, Strategic Metals Recovery Research Facility, Depart ment of Chemistry, University of Arizona, Tucson, AZ 85721
*Corresponding author ANALYTICAL CHEMISTRY, VOL. 65, NO. 10, MAY 15, 1993 · 475 A
