A C BRIEFS Quantitative Analysis of a Moisture-Cure Polyurethane Coating by Gel Permeation Chromatography Undesirable chemical reaction was eliminated by reacting - N C O with alcohol, changing the molecular size of the reactive components, and facilitating separation. N. D. KORNBAU and D. C. ZIEGLER, Research and De velopment Center, Armstrong Cork Company, Lancaster, Pa. 17604 Anal. Chem., 42, 1290 (1970) Dielectrometric Titrations: Nonquantitative Reactions Dielectrometric and spectrophotometric titrations between picric acid and pyridine or 3-iodopyridine, examples of nonquantitative reactions, were performed in benzene. Theo retical equations were devised for calculation of the titra tion curves. Except in the case of large pyridine excess each result was explained in terms of a single salt formation constant. ROBERT MEGARGLE, GEORGE L. JONES, JR., and DON ALD ROSENTHAL, Department of Chemistry, Clarkson College of Technology, Potsdam, Ν. Υ. 14676 Anal. Chem., 42, 1293 (1970)
Correspondence Kinetic Parameters from Thermogravimetric Data BENJAMIN CARROLL, Department of Chemistry, Rutgers, The State University, Newark, N. J. 07102 and EMANUEL P. MANCHE, Division of Natural Sciences and Mathemat ics, York College of the City University of New York, Flushing, Ν. Υ. 11365 Anal. Chem., 42, 1296 (1970) Kinetic Parameters from Thermogravimetric Data—A Reply SALLY A. WENTWORTH and J. H. SHARP, Department of Ceramics with Refractories Technology, The University, Sheffield, England Anal. Chem., 42, 1297 (1970)
Aids for Analytical Chemists Automation of Existing Atomic Absorption and Emission Flame Photometers with BCD Punched Tape Output for Computer Processing of Data L. T. BLOUIN, C. V. DOSTIE, W. L. BLOOM, and F. J. LOW, Parke, Davis & Co., Research Laboratories, Ann Arbor, Mich. 48106 Anal. Chem., 42, 1298 (1970) Pressure Device for Displacement of Sucrose Gradients SHERMAN R. DICKMAN and VERL J. PERRY, Department of Biochemistry, University of Utah College of Medicine, Salt Lake City, Utah 84112 Anal. Chem., 42, 1302 (1970) Atomic Absorption Spectrometry for Direct Determination of Metals in Powders M. A. COUDERT and J. M. VERGNAUD, Département de Chimie, Faculté des Sciences, Alger, Algérie Anal. Chem., 42, 1303 (1970)
New Drying Column for Air and Gases... Pressures up to 90 psig INDICATING DRIERITE IN THIS ACRYLIC UNIT DRIES AIR TO A DEW POINT OF - 1 0 0 ° F AND PROVIDES CONSTANT VISUAL ASSURANCE OF DESICCANT CONDITION The Laboratory A i r and Gas Drying U n i t w i l l completely dry air at atmospheric pressure or pressures up to 90 psig. A connection by rubber t u b i n g f r o m the air line or gas cylinder to the b o t t o m of the drier provides an immediate f l o w of dry gas. Flow rate may be 200 liters per hour or 0.1 scfm. Indicating DRIERITE is blue. W h e n exhausted it turns to a rose red or pink. The zone between the t w o colors in the c o l u m n may be purple. This zone should be a sharp, narrow color band w h e n the f l o w is at e q u i l i b r i u m . Regeneration w i l l restore the blue color. The Indicating DRIERITE gives constant visual assurance of the active desiccant. The progress of this color change upward t h r o u g h the c o l u m n is very informative. It shows the d r y i n g zone as a narrow color band w h e n the correct f l o w rates are used. The band widens w h e n o p t i m u m f l o w rates are exceeded. The Laboratory A i r and Cas D r y i n g Unit has many uses. You can dry systems prior to distillation or refluxing, pressurize electronic enclosures where dry atmospheres are required, or use as a vent drier on storage tanks or instrument compartments. The unit has applications in chromatography and can supply small flows of dry air for instruments. It can be used as a moisture indicator for laboratory gases. O r fill it w i t h Ascarite for CO2 removal, or other physical adsorbents for specific separations. DRIERITE can be easily regenerated for further use. Available f r o m your Laboratory Supply Dealer. For further i n f o r m a t i o n send for Bulletin 68. Of a d d i tional interest is o u r b o o k DRIERITE And Its Applications. DRIERITE is a product of the W . A. H A M M O N D DRIERITE C O M P A N Y , XENIA, O H I O SOLOS-LIQUIDS GASESSOUDSUOUIDSGASESSOUDS VI
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ANALYTICAL CHEMISTRY, VOL. 42, NO. 11, SEPTEMBER 1970
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