Fundamentals and Applications of Chemical Sensors
New! Dennis Schuetzle and Robert Hammerle, Editors Ford Motor Company Presents the first comprehensive collection of articles on the fundamentals and applications of a wide variety of chemical sensors. Discusses a range of topics from the development of new sensor concepts to improvements in sensors that have been mass produced for several years. Specific types of sensors discussed include oxygen, electrochemical, microbial, drug, and glucose sensors. CONTENTS Chemically Sensitive Electronic Devices · Gas Sensors in Japan · Tin Oxide Microsensors · Tin(IV) Oxide Gas Sensors · Perovskite-Type Oxides · Zirconium Oxide Oxygen Sensors · Microsensor Vapor Detectors · Chemical Microsensors · Solid State Gas Sensors · Amperometric Proton-Conductor Sensors · Atmospheric Gas Composition Determinations · Chemically Modified Electrode Sensors · Coated-Wire Ion-Selective Electrodes · Chemical Sensing · Detection of Airborne Chemicals · AmidoximeFunctionalized Coatings · Optical Waveguide Devices · Microbial Sensors · Stabilized Lipid Membranes · Design of Sensitive Drug Sensors · Subcutaneous-Type Glucose Sensors Developed from a symposium presented at the Congress of Pacific Basin Societies, Honolulu, Hawaii ACS Symposium Series No. 309 395 pages (1986) Clothbound LC 86-86-3518 ISBN 0-8412-0973-1 US & Canada $74.95 Export $89.95 Order From: American Chemical Society Distribution Office Dept. 16 1155 Sixteenth St., N.W. Washington, DC 20036 or CALL TOLL FREE 800-424-6747 and use your credit card!
Focus based detectors have great potential in this area, as discussed by Ed Yeung (Iowa State University) and Milos Novotny (Indiana University). Yeung described the use of indirect detection methods in which one probes the environment of the species rathex than the species itself. In polarimetry, for example, the signal-to-noise ratio of the background is sufficiently high that very sensitive measurements can be made. Because fluorescence detection is already highly sensitive and selective, derivatization of nonfluorescing solute molecules with fluorescing moieties is another approach to achieving sensitivity. In this way, the solute is modified to suit the detection system; usually it is the detection system that is modified to suit the solutes of interest. Because of the current interest in the newly emerging technology of SFC, several papers were given on the interfacing of SFC with spectroscopy. Dick Smith (Battelle Pacific Northwest Laboratory) described in detail the problems associated with restriction and decompression at the SFC column outlet. Jack Henion described the modification of a bench-top mass
spectrometer for SFC/MS. For FT-IR detection, deposition of the effluent on a solid surface (a moving ZnSe window, for example) before detection provides the same sensitivity advantages as noted previously for L C / F T IR. Steven Goates (Brigham Young University) presented recent results obtained from introducing the SFC column effluent into a supersonic jet for fluorescence measurements. The narrow-line fluorescence spectra obtained as a result of rotational cooling in the jet expansion region offer great improvement in the selectivity of coupled SFC/fluorescence spectroscopy. Development of modern analytical measurement techniques is driven by the desire to improve detection limits and to increase the information content of measurements. This year's Summer Symposium primarily addressed the second of these two goals. With the current interest in chromatography-spectroscopy combinations and with the rapid advancements being made in this area, there is every reason to expect that this topic will again be the central focus of a Summer Symposium in the not-too-distant future.
Cell Separations Aqueous two-phase partitioning, countercurrent chromatography, and field flow fractionation can be used to fractionate cell populations In the past several years, biochemists and cell biologists have become increasingly interested in obtaining viable, relatively homogeneous cell fractions for use in studies of cellular structure and function as well as for biotechnology applications, such as cloning and the production of monoclonal antibodies. Because of the fragile nature of cells, none of the common organic-solvent-based separatory techniques (such as solvent extraction or preparative chromatography) can be used. But three analytical techniques originally developed for separation of macromolecules—aqueous two-phase partitioning, countercurrent chromatography (CCC), and field flow fractionation (FFF)—are now being successfully applied to the fractionation of cell populations, as described recently at the 10th International Symposium on Column Liquid Chromatography (HPLC '86) in San Francisco, Calif.
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Aqueous two-phase partitioning Aqueous solutions of dextran (Dx) and polyethylene glycol (PEG), when mixed above certain concentrations, form immiscible liquid two-phase systems consisting of a PEG-rich top layer and a Dx-rich bottom layer. These aqueous polymer systems have been found useful not only for fractionation of proteins and nucleic acids, but also for fractionation of cells, as described at the symposium by Harry Walter of the Veterans Administration Medical Center in Long Beach, Calif. "Particles usually partition between one of the phases and the interface (unlike soluble materials, which partition between the bulk phases)," Walter explains. "The normal position of cells in a two-phase polymer system is at the interface, so whenever you see partitioning it indicates that something is acting on the cells to pull them out of the interface and into one
