UPCOMING RESEARCH Comparison of Covalent and Noncovalent Labeling with Near-Infrared Dyes for the High-Performance Liquid Chromatographic Determination of Human Serum Albumin
Determination of Nanomolar Concentrations of Individual Dissolved Low Molecular Weight Amines and Organic Acids in Seawater
Covalent and noncovalent labeling of h u m a n serum albu min with near-IR polymethine cyanine dyes is compared for reversed-phase a n d size exclusion HPLC analysis. The advantages of covalent labeling are presented and discussed. Richard J. Williams, Malgorzata Lipowska, Gabor Patonay*, and Lucjan Strekowski, Department of Chemis try, Georgia State University, University Plaza, Atlanta, GA 30303
A passive diffusion technique is combined with GC to concentrate and determine low molecular weight amines and organic acids in seawater. Natural concentrations of 10 nM can be measured in 500 mL of seawater. Xiao-Hua Yang, Cindy Lee*, and Mary I. Scranton, Marine Sciences Research Center, State University of New York, Stony Brook, NY 11794-5000
Enzymatic Determination of Carbon-14-Labeled D-p-Hydroxybutyrate in Biological Samples A method to determine labeled Β-β-hydroxybutyrate and its specific radioactivity is based on a change in the phys ical properties of ϋ-β-hydroxybutyrate by specific en zyme-mediated transformation into the phenylhydrazone of acetoacetate. This allows quantitative separation from other compounds by trapping t h e phenylhydrazone in SPE C 1 8 columns. S. Quevedo, A. Palou*, and P. Roca, Departament de Biologia Fonamental i Ciències de la Salut (Bioquimica i Biologia Molecular), Universitat de les Illes Balears i Institut d'Estudis Avançais (UIB-CSIC), Ctra Valldemossa Km 7.5, 07071 Palma de Mallorca, Spain Study of Sonication and Supercritical Fluid Extraction of Primary Aromatic Amines A study of parameters affecting extraction efficiency of p r i m a r y aromatic amines from solid samples is presented. SFE using N 2 0 a s supercritical fluid and 1,6hexanediamine in methanol a s a modifier yields significantly better recoveries than classical methods. T. S. Oostdyk, R. L. Grob, J. L. Snyder, and M. E. McNally*, Chemistry Department, Villanova University, Villanova, PA 19085 Investigation of the Kinetic Properties of Particle-Loaded Membranes for Solid-Phase Extraction by Forced Flow Planar Chromatography Solid-phase extraction using particle-loaded membranes is normally performed a t flow rates t h a t generate four to nine theoretical plates. Existing models for predicting breakthrough volumes from chromatographic data can, in many cases, be applied successfully to membranes. W. Peter N. Fernando, Mary L. Larrivee, and Colin F. Poole*, Department of Chemistry, Wayne State University, Detroit, MI 48202
These articles are scheduled to appear in AC RESEARCH in the near future. "•"Corresponding author
Application of Square Wave Voltammetry to Strongly Adsorbed Quasireversible Redox Molecules Theory is presented for monolayer or lower coverage of equivalent noninteracting redox adsorbates. Major theoretical predictions are confirmed in experiments using adsorbed cytochrome c on COOH-alkylthiolate/gold selfassembled monolayer electrodes. James H. Reeves*, Department of Chemistry, University of North Carolina at Wilmington, 601 S. College Road, Wilmington, NC 28409 and Shihua Song and Edmond F. Bowden*, Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204 Molar Response of Polychlorinated Dibenzo-p-dioxins and Dibenzofurans by the Mass Spectrometric Detector The problem of dioxin solution standards is examined using mass spectrometric detection in capillary GC. Heinz Schimmel, Bernhard Schmid, Reiner Bâcher, and Karlheinz Ballschmiter*, Department of Analytical and Environmental Chemistry, University of Ulm, Albert-Einstein Allée 11, D-7900 Ulm, Germany Enzyme-Based Fiber Optic Zinc Biosensor A fiber optic metal ion biosensor t h a t can detect zinc specifically a t nanomolar concentrations is described. Metal ion concentration is proportional to a ratio of fluorescence intensities. Richard B. Thompson* and Eric R. Jones, Department of Biological Chemistry, University of Maryland School of Medicine, 108 N. Greene St., Baltimore, MD 21201, and Center for Bio/Molecular Science and Engineering, Code 6090, Naval Research Laboratory, Washington, DC 20375-5000 Automated Selection of Regression Models Using Neural Networks for 13C NMR Spectral Predictions A method using neural networks to select regression models for 1 3 C NMR spectral predictions is developed. This method selects models for a 30-compound prediction set consisting of various organic structural classes and predicts their spectra with a mean rms spectral error of 1.11 ppm. Jon W. Ball and Peter C. Jure*, Department of Chemistry, The Pennsylvania State University, 152 Davey Laboratory, University Park, PA 16802
ANALYTICAL CHEMISTRY, VOL. 65, NO. 4, FEBRUARY 15, 1993 · 197 A
