BRIEFS Diffusional Distortion in the Monitoring of Dynamic Events
652 The effects of diffusion over microscopic distances between the source of a chemical event and the point of observation are studied theoretically with a convolution procedure and experimentally with a microelectrode probe experiment. Royce C. Engstrom*, R. Mark Wightman, and Eric W. Kristensen, Department of Chemistry, Indiana University, Bloomington, Ind. 47405 ' Anal. Chem., 60 (1988) Voltammetry without Supporting Electrolyte Using a Platinum Working Electrode Supported on an Ion Exchange Membrane 657 A platinum on Nafion perfluorosulfonate electrode assem bly separates an analyte solution containing no supporting electrolyte from an electrolyte solution containing counter and reference electrodes. Thomas W. Kaaret and Dennis H. Evans*, Department of Chem istry and Biochemistry, University of Delaware, Newark, Del. 19716 Anal. Chem., 60 (1988) Multichannel Crossed-Beam Thermal Lens Measurements for Absolute Absorbance Determination with Pulsed Laser Excitation 662
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AMETEK THERMOX INSTRUMENTS DIVISION
CIRCLE 5 ON READER SERVICE CARD 426 A · ANALYTICAL CHEMISTRY, VOL. 60, NO. 7, APRIL 1, 1988
By simultaneously measuring the crossed-beam thermal lens signal at 128 points within a sample, the absolute absor bance of a sample is determined with a single laser pulse. Wayne A. Weimer, Naval Weapons Research Center, China Lake, Calif. 93555, and Norman J. Dovichi*, Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2 Anal. Chem., 60 (1988) Enhanced Fluorescence Detection of Dansyl Derivatives of Phenolic Compounds Using a Postcolumn Photochemical Reactor and Application to Chlorophenols in River Water 666 Photochemical decomposition of the derivatives leads to formation of highly fluorescent dansyl-OH and dansylOCH3 with a reproducible linear response over 3 orders of magnitude and up to 8000-fold signal enhancement. Cornells de Ruiter, Jan F. Bohle, Gerhardus j . de Jong, Udo A. Th. Brinkman, and Roland W. Frei*, Department of Analytical Chemistry, Free University, De Boelelaan 1083, 1081 HV Amster dam, The Netherlands Anal. Chem., 60 (1988) Phase Fluorometric Method for Determination of Standard Lifetimes 670 A multifrequency phase fluorometric method for accurately determining the lifetimes of monoexponential fluorophore without reference to another is described. Results are shown for some widely used standard fluorophores and for some recently developed compounds. Richard B. Thompson*, Bio/Molecular Engineering Branch, Code 6190, Naval Research Laboratory, Washington, D.C. 20375-5000, and Enrico Gratton, Department of Physics, Laboratory for Fluo rescence Dynamics, University of Illinois, Urbana, 111. 61801 Anal. Chem., 60 (1988)
