The Structures of Cellulose - ACS Publications - American Chemical

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BRIEFS

The Structures of Cellulose

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ecent technological advances have given scientists state-of-the-art methods to use in the examination of cellulose, the principal constituent of plant cell walls. This book looks at the latest instrumentation and procedures used to delineate cellulose structure. You'll read about studies of wood and cotton— the primary sources of naturally occurring cellulose—and discover the changes that occur to their basic crystalline form when subjected to mechanical or chemical processes. The editor begins this book with a comprehensive overview chapter that sets the structural problem in perspective. The remaining chapters present various aspects of cellulose structure, including • X-ray Diffraction Studies of Ramie Cellulose · Two Crystalline Forms in Native Celluloses · Irreversibility Between Cellulose I and II · Raman Spectra of Cellulose · Aspects of Recrystallized Cellulose · Fractal Analysis of Cotton Cellulose · Alkaline Degradation of Hydrocellulose. This book will prove valuable to all scientists seeking to organize the chemical or biological data of cellulose in relation to its structure· Rajai H. Atalla, Editor, ACS Symposium Series No. 340 LC 87-11537 ISBN 0-8412-1032-2

328 pages (1987) Clothbound US & Canada $69.95 Export $83.95

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Graphics for Chemical Structures

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his exciting book presents the latest information from recognized experts in the field of chemical structure handling on microcomputers... and includes the newest developments in related systems on both mini- and mainframe computers. The book begins with an excellent overview of the evolution of computer graphics—and will introduce you to the four general types of software packages currently available · scientific word processing packages • packages that allow graphics entry of chemical structures but do not allow substructure searching or interfacing with other systems · packages that allow graphics structure entry and substructure searching and interfacing with other systems · packages designed to act as front ends to molecular modeling systems. This volume continues with discussions and comparisons of various software packages for the chemist. Information managers, information scientists, systems analysts, bench chemists, physical chemists, and PC enthusiasts will find this book a vital, necessary reference. Wendy A. Warr, Editor ACS Symposium Series No. 341 LC 87-3575 ISBN 0-8412-1401-8

176 pages (1987) Clothbound US & Canada $44.95 Export $53.95

Order from: American Chemical Society, Distribution Office Dept. 58 1155 Sixteenth St., N.W., Washington, DC 20036 or CALL TOLL FREE

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494 A · ANALYTICAL CHEMISTRY, VOL. 60, NO. 8, APRIL 15, 1988

Electron Capture Negative Ion Mass Spectra of Halogenated Diphenylethane Derivatives 787 The methane ECNI mass spectra of 17 halogenated diphenyl ethane, ethene, and ethanol derivatives (such as DDT, DDE, and dicofol) are reported. These three groups of compounds show spectral differences that reflect the nature of the base molecular structure. E. A. Stemmler and Ronald A. Hites*, School of Public and Environmental Affairs and Department of Chemistry, Indiana University, Bloomington, Ind. 47405 Anal. Chem., 60 (1988) Behavior of Liposomes in Flow Injection Systems

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Liposomes are stable at flow rates of up to 2 mL/min, and variations between flow profiles of small solute molecules and liposomes can be explained by diffusion coefficient differences. Laurie Locascio-Brown*, Anne L. Plant, and Richard A. Durst, Center for Analytical Chemistry, National Bureau of Standards, Gaithersburg, Md. 20899 Anal. Chem., 60 (1988) Reversed-Phase Chromatographic Separation of Highly Charged Inorganic Cations and Anions Using Ion Interaction Reagents and Competing Ions 797 Reversed-phase LC separations of inorganic complexes with charges to 4 + and 3~ are achieved in separation times of as little as 15 min. The method is applicable to a wide range of preparative, kinetic, and photochemical studies. A. D. Kirk* and A. K. Hewavitharana, Department of Chemistry, University of Victoria, Victoria, British Columbia, Canada V8W 2Y2 Anal. Chem., 60 (1988) Ultraviolet-Absorption Detector for Capillary Supercritical Fluid Chromatography with Compressible Mobile Phases 802 Cooling the ultraviolet absorption detector flow cell is shown to reduce baseline drift in capillary supercritical fluid chromatography. The detection limit for chrysene is ~30 pg at a signal-to-noise ratio of three. Steven M. Fields, Karin E. Markides, and Milton L. Lee*, Department of Chemistry, Brigham Young University, Provo, Utah 84602 Anal. Chem., 60 (1988) Liquid Chromatographic Artifacts and Peak Distortion: SampleSolvent Interactions in the Separation of Carotenoids 807 In the separation of carotenoids by LC, the interaction between solute molecules, injection solvent, and mobile phase can result in the production of peaks that may erroneously indicate the presence of impurities or «s-carotenoids. Frederick Khachik*, Gary R. Beecher, Joseph T. Vanderslice, and Greg Furrow, Nutrient Composition Laboratory, BHNRC, ARS, U.S. Department of Agriculture, Beltsville, Md. 20705 Anal. Chem., 60 (1988) Electron Capture Sulfur Detector: Reduced Sulfur Species Detection at the Femtomole Level 812 Reduced sulfur compounds are fluorinated after GC separation, then detected with an ECD. For H 2 S, OCS, CH 3 SH, CH3SCH3, and CS2, a calculated detection limit of