UPCOMING RESEARCH Chemical Generation of Chlorine, Bromine, and Iodine for Sample Introduction into a Surfatron-Generated Argon Microwave-Induced Plasma
Polymeric Porogens Used in the Preparation of Novel Monodispersed Macroporous Polymeric Separation Media for High-Performance Liquid Chromatography
A continuous-flow system for the simultaneous genera tion of chlorine, bromine, and iodine gas is coupled to a ΜΙΡ-surfatron. Halogens can be measured within t h e range of 0.25-75 μg/mL. M. Dolores Calzada, M. Carmen Quintero, Antonio Gamero*, and Mercedes Gallego, Department of Applied Physics, Faculty of Sciences, University of Cordoba, 14071 Cordoba, Spain
Size-monodispersed beads with large pores, prepared with a solution of polymeric porogens, give excellent r e sults in the reversed-phase separation of proteins and in size-exclusion chromatography. Q. Ching Wang, Ken Hosoya, Frantisek Svec, and Jean M. J. Fréchet*, Department of Chemistry, Baker Laboratory, Cornell University, Ithaca, NY 14853-1301
Pulse Voltammetry in Single Cells Using Platinum Microelectrodes Multiple-pulse voltammetry at platinum electrodes is de scribed for intracellular analysis. This technique shows repeatable voltammetry for biological samples and mini mizes deterioration of voltammetric signals at electrodes used in biological microenvironments. Ta Kung Chen, Yau Yi Lau, Danny Κ. Υ. Wong, and An drew G. Ewing*, Department of Chemistry, 152 Davey Labora tory, Penn State University, University Park, PA 16802 Direct Detection and Identification of Volatile Organic Compounds Dissolved in Organic Solvents by Reversed-Phase Membrane Introduction Tandem Mass Spectrometry Reversed-phase membrane introduction tandem MS can be used for rapid determination of sub-ppm concentra tions of organic compounds in aliphatic and aromatic sol vents. Frants R. Lauritsen, Tapio Kotiaho, Tarun K. Choudhury, and R. Graham Cooks*, Department of Chemistry, Purdue University, West Lafayette, IN 47907 Sub-Femtomole Determination of PhenylthiohydantoinAmino Acids: Capillary Electrophoresis and Thermooptical Detection Twenty PTH amino acids are separated by micellar CE in 13.5 min. Detection limits are ~ 3 orders of magnitude superior to those obtained with conventional LC. Karen C. Waldron and Norman J. Dovichi*, Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
These articles are scheduled to appear in AC RESEARCH in the near future. Corresponding author
Permeability of Glucose and Other Neutral Species through Recast Perfluorosulfonated lonomer Films Effective diffusion coefficients of the neutral forms of glucose, hydroquinone, and ascorbic acid in recast Nafion films range from 3.4 to 22 χ 10~ 8 cm 2 /s. Thermally curing the film reduces these values twofold to eightfold. Zhonghui Fan and D. Jed Harrison*, Department of Chem istry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2 Molecular Weight Distributions of Water-Soluble Polymers by Flow Field-Flow Fractionation A new flow FFF method determines polymer molecular weight distributions by converting measured diffusion coefficients through the use of available Mark-Houwink constants. J. J. Kirkland*, C. H. Dilks, Jr., and S. W. Rementer, E. I. DuPont de Nemours and Company, Central Research and Devel opment, Experimental Station, P.O. Box 80228, Wilmington, DE 19980-0228 Superficially Porous Silica Microspheres for the Fast High-Performance Liquid Chromatography of Macromolecules Superficially porous silica microspheres composed of a 5-μπι solid core and a 1-μπι- thick outer shell with 300 -À pores show distinct advantages for the HPLC separation of macromolecules. J. J. Kirkland*, E. I. DuPont de Nemours and Company, Central Research and Development, Experimental Station, P.O. Box 80228, Wilmington, DE 19980-0228 Liquid Chromatographic Separation Schemes for Pyrrole and Pyridine Nitrogen Aromatic Heterocycle Fractions from Crude Oils Suitable for Rapid Characterization of Geochemical Samples Direct separations are performed on a polar aminocyanobonded silica column. The separation schemes developed are suitable for rapid characterization of geochemical samples. Maowen Li, Stephen R. Larter*, and Daniel Stoddart, Newcastle Research Group in Fossil Fuels & Environmental Geochemistry, Drummond Building, The University, Newcastle upon Tyne, NE1 7RU, U.K. and Malvin Bjor0y, Geolab Nor, Hornebergveien 5, P.O. Box 1581, 7002 Trondheim, Norway ANALYTICAL CHEMISTRY, VOL. 64, NO. 10, MAY 15, 1992 • 561 A
UPCOMING RESEARCH Molecular Theory of Chromatographic Selectivity Enhancement for Blocklike Solutes in Anisotropic Stationary Phases and Its Application
Steric Factors Affecting the Discrimination of Isomeric and Structurally Related Olefin Gases and Vapors with a Reagent-Coated Surface Acoustic Wave Sensor
An equation based on a lattice-fluid model and applica ble to GC, LC, and SFC is derived, interpreted, and tested experimentally. Chao Yan and Daniel E. Martire*, Department of Chemistry, Georgetown University, Washington, DC 20057-2222
High sensitivity for the less hindered members of three series of olefins is achieved by using a 30-MHz SAW os cillator coated with one of several Pt(II)-ethylene π-complexes. Detection limits range from ~ 2 to 70 Hg/L. Edward T. Zellers* and Guo-Zheng Zhang, University of Michigan, Department of Environmental and Industrial Health, School of Public Health, 1420 Washington Heights, Ann Arbor, MI 48109-2029
Equilibrium Studies on Colorimetric Plastic Film Sensors for Carbon Dioxide The equilibrium responses (as a function of percent C 0 2 and temperature) are reported for plastic colorimetric film C 0 2 direct sensors that use a phase transfer agent to solubilize the sensing dye. Andrew Mills*, Qing Chang, and Neil McMurray, Depart ment of Chemistry, University College of Swansea, Singleton Park, Swansea SA2 8PP, U.K. Electrochemical Characteristics of Amino Acids and Peptides Derivatized with Naphthalene-2,3-dicarboxaldehyde: pH Effects and Differences in Oxidation Potentials The variance of half-wave potentials by ~ 200 mV for 18 derivatized amino acids and 15 derivatized peptides indi cates that voltammetry can enhance identification and selective detection. The pH independence of the oxidation potential allows for the control of selectivity in the pres ence of pH-dependent oxidizable compounds such as phe nols. Mark A. Nussbaum*, Jill E. Przedwiecki, and Daniel U. Staerk, Department of Chemistry, Ripon College, Ripon, WI 54971 and Susan M. Lunte and Christopher M. Riley, Cen ter for Bioanalytical Research and the Department of Pharma ceutical Chemistry, University of Kansas, 2095 Constant Ave nue, Lawrence, KS 66047 Thin Aluminum Nitride Film Resonators: Miniaturized High Sensitivity Mass Sensors A piezoelectric mass sensor based on existing thin alumi num nitride film resonator technology is developed. Per formance characteristics, including a high mass sensitiv ity ( — 5 5 0 cm 2 /g), are evaluated and discussed. Ronald P. O'Toole, Stanley G. Burns, Glenn J. Bastiaans, and Marc D. Porter*, Department of Electrical Engineering and Computer Engineering, Microelectronics Research Center, Center for Advanced Technology Development, Center for Microanalytical Instrumentation, Ames Laboratory-USDOE, and Department of Chemistry, Iowa State University, Ames, IA 50011 Compensating for Instrumental and Sampling Biases Accompanying Electrokinetic Injection in Capillary Zone Electrophoresis Measurements of integrated injection current and sample solution conductivities can be used to correct for sam pling biases in electrokinetic injection in CZE. Thomas T. Lee and Edward S. Yeung*, Department of Chemistry and Ames Laboratory-USDOE, Iowa State Univer sity, Ames, IA 50011
Evaluation of Transient Responses of Ammonia-Selective Potentiometric Electrodes for Quantitative Applications An error-compensating, predictive kinetic method is adapted a n d evaluated for q u a n t i t a t i v e applications based on transient responses from an ammonia-selective electrode. Predicted values of equilibrium signal are close to measured values and exhibit the expected logarithmic dependence on ammonia concentration in t h e range 0 . 1 100 nmol/L. Michael D. Love, Harry L. Pardue*, and Gelson Pagan, Department of Chemistry, Purdue University, 1393 Brown Building, West Lafayette, IN 47907-1393 Preparation of Polyacrylamide Gel-Filled Capillaries for Ultrahigh Resolution of Polynucleotides by Capillary Gel Electrophoresis A simple method is established for the production of sta ble and bubble-free polyacrylamide gel-filled capillaries t h a t demonstrate high precision, ultrahigh resolving power, and wide applicability. Yoshinobu Baba*, Toshiko Matsuura, Kyoko Wakamoto, Yoshiko Morita, Yumi Nishitsu, and Mitsutomo Tsuhako, Kobe Women's College of Pharmacy, Kitamachi, Motoyama, Higashinada-ku, Kobe 658, Japan Isotope Dilution Liquid Chromatography/Mass Spectrometry Using a Particle Beam Interface Quantitative isotope dilution analysis using particle beam LC/MS, free of co-elution enhancement effects, is described. An equation is derived allowing use of either single- or multiple-labeled isotopic internal standards. Daniel R. Doerge*, Mike W. Burger, and Steve Bajic, De partments of Environmental Biochemistry and Chemistry, Uni versity of Hawaii at Manoa, Honolulu, HI 96822 and VG BioTech, Altrincham, Cheshire, U.K. Metal - Dispersed Carbon Paste Electrodes Preparation of electrocatalytic carbon paste electrodes by mixing metallized graphite with an organic pasting liquid is described. These electrodes couple the inherent proper ties of carbon paste surfaces with the efficient catalytic activity of metal sites. Joseph Wang*, Najih Naser, Lucio Angnes, Hui Wu, and Liang Chen, Department of Chemistry, New Mexico State Uni versity, Las Cruces, NM 88003
ANALYTICAL CHEMISTRY, VOL. 64, NO. 10, MAY 15, 1992 • 563 A
