A C BRIEFS Highlights of Articles in This Issue
A Computer Operated Mass Spectrometer System
Electrochemical Reduction of Phenol Red
A computer-controlled mass spectrometer with fourfold increase in ion detection efficiency is described. Signal integration and computer-managed data are provided.
Electrochemical studies reveal that phenol red is reduced at a mercury electrode in two steps, with the product of the first electron transfer undergoing a second order disproportionation.
W. E. REYNOLDS, V. A. BACON, J. C. BRIDGES, T. C. COBURN, BERTHOLD HALPERN, JOSHUA LEDERBERG, E. C. LEVINTHAL, ERNEST STEED, and R. B. TUCKER. Department of Genetics, Stanford University School of Medicine, Stanford, Calif. 94305 Anal. Chem., 42, 1122
(1970)
Ion Microprobe Mass Spectrometric Analysis of Oxygen in Copper A method lias been mass spectrometer a copper matrix. detection limits of tained.
developed employing an ion microprobe to determine oxygen concentrations in Precision and accuracy of 20-25% and 10-20 ppmw of oxygen have been at-
C. A. EVANS, JR., Ledgemont Laboratory, per Corporation, Lexington, Mass. 02173
Kennecott Cop-
Anal. Chem., 42, 1130 (1970)
Determination of C 1 2 Alkylnaphthalenes and Methylbiphenyls in Aromatic Fractions by Capillary Gas Chromatography A description is given of the separation of these hydrocarbons in fractions of pyrolysis/steam cracker/oil and black coal tar, using three capillary columns with different selectivities. JIR MOSTECKY, MILAN POPL, and JOSEF KRIZ, Institute of Chemical Technology, Department of Synthetic Fuel and Petroleum, Technickâ 1905, Praha 6, Czechoslovakia Anal. Chem., 42, 1132
(1970)
J. K. SENNE and L. W. MARPLE, Department of Chemistry, Iowa State University, Ames, Iowa 50010 Anal. Chem., 42, 1147 (1970) Interactive Electronic Analytical Instrumentation Based on Computerized Experimental Design This paper describes the design of a specialized hardware computer to perform interrupted-sweep stationary electrode polarography using medium-scale integrated circuit tech nology. D. 0. JONES and S. P. PERONE, Department of Chemistry, Purdue University, Lafayette, Ind. 47907 Anal. Chem., 42, 1151 (1970) Kinetics and Analytical Applications of the Ruthenium Catalyzed Reaction between Cerium(IV) and Arsenic(lll) in Sulfuric Acid Medium Kinetic data and an empirical rate expression are given for the ruthenium catalyzed Ce(IV)-As(III) redox reaction. Selective analyses of nanomolar mixtures of Os and R u are reported. JAMES B. WORTHINGTON and HARRY L. PARDUE, Depart ment of Chemistry, Purdue University, Lafayette, Ind. 47907 Anal. Chem., 42, 1157 (1970) Direct Current, Alternating Current, Rapid, and Inverse Polarographic Methods for Determination of Tin(IV)
A New Approach to Automating an Analytical Gas Chromatograph
Six polarographic techniques, conventional ac and dc, rapid ac and dc, and inverse ac and dc polarography, as applied to the direct analysis of tin(IV) have been compared.
A novel automatic gas chromatograph to handle discrete liquid samples is described.
A. M. BOND, Department of Inorganic Chemistry, Univer sity of Melbourne, Parkville, Victoria 3052, Australia
P. B. STOCKWELL and R. SAWYER, Laboratory of the Government Chemist, Cornwall House, Stanford St., London, SW 1, England Anal. Chem., 42, 1136 (1970) Chromatographic Peak Capacity and the Factors Influencing It Peak capacity is an important measure of the efficiency of various chromatographic systems. In order to increase the peak capacity careful evaluation of the experimental condition must be made. EL/ GRUSHKA, Department of Chemistry, State of New York at Buffalo, Buffalo, Ν. Υ. 14214
University
Anal. Chem., 42, 1142 (1970)
Anal. Chem., 42, 1165
(1970)
Use of Polarographic Methods for the Determination of Tin in Geological Samples Polarographic methods for determination of tin in geological samples have been investigated. Ac polarography provides a means for simple, direct, and quantitative determination in most samples. A. M. BOND, T. A. O'DONNELL, and A. B. WAUGH, Depart ment of Inorganic Chemistry, University of Me/bourne, Parkville, Victoria, 3052, Australia and R. J. W. MC LAUGHLIN, Department of Geology, University of Mel bourne, Parkville, Victoria, 3052, Australia Anal. Chem., 42, 1168 (1970)
ANALYTICAL CHEMISTRY, VOL. 42, NO. 11, SEPTEMBER 1970
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Computer Approach to Ion-Selective Electrode Potentiometry by Standard Addition Methods
Intel-laboratory Evaluation of a Material with Unequal Numbers of Replicates
Methods are described which allow the determination of unknown concentrations using an ion-selective electrode without prior calibration. Computer methods are used to calculate the results.
A statistical procedure is presented for obtaining a properly weighted average of measurements, obtained by round robin procedures, in cases of unequal numbers of replicates in the different laboratories.
M. J. D. BRAND and G. A. RECHNITZ, Department of Chemistry, State University of New York, Buffalo, Ν. Υ. 14214 Anal. Chem., 42, 1172 (1970)
JOHN MANDEL and ROBERT C. PAULE, National of Standards, Washington, D. C. 20234
Bureau
Anal. Chem., 42, 1194 (1970) Determination of Oxazoline in the Presence of Aziridine
Environmental Effects upon Fluorescence of 5- and 8-Hydroxyquinoline T h e principal decay process competing with fluorescence is internal conversion to the ground state, the efficiency of which is enhanced by both intermolecular and intramolecu lar hydrogen-bond formation.
A new method for determination of oxazoline plus aziridine has been developed, employing a solution of morpholine in chlorobenzcne as back-titrant. A one sigma standard deviation of ± 0 . 3 % was obtained.
MICHAEL GOLDMAN and E. L. WEHRY, Department of Chemistry, Indiana State University, Bloomington, Ind. 47401 Anal. Chem., 42, 1178 (1970)
RONALD D. LAW, Product and Methods Development, Re search and Development Laboratories Division, Thiokol Chemical Corporation, Wasatch Division, Brigham City, Utah 84302 Anal. Chem., 42, 1198 (1970)
Environmental Effects upon the Photoluminescence of 8-Quinolineboronic Acid
Properties of the Chelating Polymer Poly-(Triaminophenol-Glyoxal) in the Microanalysis of Copper
Unlike 5- and 8- hydroxyquinolines, a low-lying (η,π*) singlet appears important in determining the luminescence of 8-quinolineboronic acid. The results indicate significant excited-state interaction of hydroxylic species with the boronic acid group.
The method uses a specific chelating agent in a column to remove copper from solution. The concentrated metal is then eluted from the chelate and determined by atomic absorption spectrometry.
MICHAEL GOLDMAN and E. L. WEHRY, Department of Chemistry, Indiana University, Bloomington, Ind. 47401 Anal. Chem., 42, 1186
(1970)
A Rapid Sampler for Intermediate Speed Reactions
Simplified Spectrophotometric Determination of Acid Dissociation Constants A simplified method for the spectrophotometric determina tion of acid dissociation constants has been developed. The equations for calculating the acid dissociation constants are presented. JOHN 0. FROHLIGER, Department of Occupational Health, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pa. 15213 and JOSEPH E. DZIEDZIC and OMAR W. STEWARD, Department of Chemistry, Duquesne University, Pittsburgh, Pa. 15219 Anal. Chem., 42, 1189
(1970)
Determination of Carbon-13 by Infrared Spectrophotometry of Carbon Monoxide T h e absolute abundance of 13C in 13 CO -f- 12 CO mixtures is determined to within a few per cent by measuring the peak absorbancs of the R(13) lines in the vibrational fundamen tals of 1 2 C0 and l a C 0 . ROBIN S. McDOWELL, LOS Alamos Scientific Laboratory, University of California, Los Alamos, Ν. Μ. 87544 Anal. Chem., 42, 1192
ALBERT ZLATKIS, WILHELM BRUENING, and ERNST BAYER, Department of Chemistry, University of Houston, Houston, Texas 77004 Anal. Chem., 42, 1201 (1970)
(1970)
A rapid-mixing and multi-sampling device for sampling reaction mixtures at intervals of 0.5 to 50 seconds has been designed to determine rates of intermediate speed re actions. HARRY C. FROEDE, JOHN COWAN, TED W. REID, and IRWIN B. WILSON, Department of Chemistry, University of Colorado, Boulder, Colo. 80302 Anal. Chem., 42, 1204 (1970) Determination of Submicrogram Amounts of Chromium by Coulometric Titrimetry An improved method has been developed for the titi ition of 30 ,ug to 15 ng of chromium with coulometrically-generated ferrous ion. The method is bias free. It is shown that the end-point determination is the limiting factor in the method. C. E. CHAMPION, G. MARINENKO, and J. K. TAYLOR, In stitute for Materials Research, National Bureau of Stan dards, Washington, D. C. 20234 and W. E. SCHMIDT, Chemistry Department, George Washington University, Washington, D. C. 20006 Anal. Chem., 42, 1210
ANALYTICAL CHEMISTRY, VOL. 42, NO. 11, SEPTEMBER 1970
(1970) ·
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AC Matching of Mass Spectra When Peak Height Is Encoded to One Bit Disagreement statistics have been calculated for a library of 3000 organic mass spectra. A theory is derived permitting accurate prediction of these results from the spectral group statistics. S. L. GROTCH, Jet Propulsion Laboratory, stitute of Technology, Pasadena, Calif.
California
Anal. Chem., 42, 1214
In
(1970)
BRIEFS
Distribution Studies between Thenoyltrifluoroacetone (TTA) in Methyl Isobutyl Ketone (MIBK) and Aqueous Solutions Using Radiotracers of Group II and Group III Elements Studies of the Group I I and Group I I I elements using this solvent extraction system have shown that many quanti tative single stage separations are possible. W. MORRISON JACKSON, GEOFFREY I. GLEASON, and PERCY J. HAMMONS, JR., Special Training Division, Oak Ridge Associated Universities, Oak Ridge, Tenn. Anal. Chem., 42, 1242
Analysis of Steroid Hormones Using High Resolution Liquid Chromatography Fast, high resolution separations of steroid hormones were achieved with modest instrumentation using reversed phase liquid-liquid partition chromatography. Optimization of separations was achieved by varying the stationary phase loading on a hydrophobic support. SIDNEY SIGGIA and ROBERT A. DISHMAN, University Massachusetts, Amherst, Mass. Anal. Chem., 42, 1223
of
(1970)
(1970)
X-Ray Excited Optical Fluorescence Spectrometry: Scope of Application to Trace Rare Earth Determinations X - R a y excited optical fluorescence spectrometry is capable of detecting the presence of rare earth impurities at con centrations of 100 ppm or less in compounds prepared from 49 of the chemical elements. The excitation mechanism for production of these spectra is also reviewed. EDWARD L. DeKALB, ARTHUR P. D'SILVA, and VELMER A. FASSEL, Institute for Atomic Research and Department of Chemistry, Iowa State University, Ames, Iowa 50010 Anal. Chem., 42, 1246 (1970)
Determination of Moisture in Starch Hydrolyzates by Near-Infra red and Infrared Spectrophotometry
Computer Calculations of Escape Curves of Nonideal Solutes in Thin Film Dialysis
Moisture content of starch hydrolyzates can be determined directly by using either near-infrared or infrared spectro photometry. The results compare favorably with the vacu um-oven filter-aid procedure. DANIEL W. VOMHOF and JAMES H. THOMAS, Bureau of Standards, Washington, D. C. 20234 Anal. Chem., 42, 1230
The analytical thin film dialysis behavior of solutes which exhibit monomer-monomer interconversion or monomerpolymer aggregation has been studied by computer simula tion.
National KENT K. STEWART, L. C. CRAIG, and R. C. WILLIAMS, JR., The Rockefeller University, New York, Ν. Υ. 10021 (1970) Anal. Chem., 42, 1252 (1970)
Analysis of the Polarographic Method of Studying Metal Complex Equilibria
Notes
An error analysis of the polarographic method of studying metal complex equilibria is presented. The limitations of this technique are discussed in detail.
Thin Film Dialysis Studies with Highly Acetylated Cellophane Membranes
LEON N. KLATT and RUSSELL L. ROUSEFF, Department of Chemistry, University of Georga, Athens, Ga. 30601 Anal. Chem., 42, 1234
(1970)
Highly acetylated cellophane membrane prepared for thin film dialysis permit only a slow diffusion of tritiated water and are highly selective for a variety of small solutes. KENT K. STEWART and LYMAN C. CRA/G, The Rockefeller University, New York, Ν. Υ. 10021 Anal. Chem., 42, 1257
(1970)
A Complexometric Titration for the Determination of Sodium Ion
Cinnamo- and 2-Furohydroxamic Acid Chelates
Stability constants of both the sodium and potassium com plexes of C y D T A are determined and the fourth acid dis sociation constant of C y D T A is redetermined in the light of these stabilities.
Cinnamo- and 2-furohydroxamic acid chelates of V ( V ) , T i ( I V ) , F e ( I I I ) , V 0 2 ( I I ) and Os(VIII) were investigated. Absorption curves, effect of p H on absorption, structure studies, and interfering ions were examined for each system.
JAMES D. CARR and D. G. SWARTZFAGER, Department of Chemistry, University of Nebraska, Lincoln, Neb. 68508 Anal. Chem., 42, 1238
(1970)
RONALD ROWLAND and CLIFTON E. MELOAN, Depart ment of Chemistry, Kansas State University, Manhattan, Kan. Anal. Chem., 42, 1261 (1970)
ANALYTICAL CHEMISTRY, VOL. 42, NO. 11, SEPTEMBER 1970
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AC BRIEFS Fluorometric Determination of Quantities of Thorium
Determination of Polymer Composition of Rubber Vulcanizates
Submicrogram
T h e fluorometric method using 3,4',7-trihydroxyflavone has a detection limit of 0.03 /ig of thorium and a precision to about 1% on 10 /ug. Unlike morin, 3,4',7-trihydroxyflavone is not sensitive to beryllium. T. D. FILER, Health Services Laboratory, Energy Commission, Idaho Falls, Idaho
U. S.
Atomic
Anal. Chem., 42, 1265
(1970)
D. W. CARLSON, H. C. RANSAW, and A. G. ALTENAU, The Firestone Tire & Rubber Company, Central Research Laboratories, Akron, Ohio 44317 Anal. Chem., 42, 1278
Gas Chromatographic Study of Interactions between Aliphatic Amines and Metallic Ions T h e retention volumes of 13 aliphatic amines were measured on columns whose stationary phases were solutions of metallic stéarates in Quadrol. The results are discussed in terms of the metallic ion and the structure of the amine. R. C. CASTELLS and J. A. CATOGGIO, Departmento de Quimica Analitica, Facultad de Ciencias Exactes, Universidad Nacional de La Plata, 47 esq. 115, La Plata, Rep. Argentina Anal. Chem., 42, 1268
The composition and microstructure of the polymers in rubber vulcanizates were determined by infrared and N M R .
(1970)
Termonomer Analysis in Ethylene Propylene Terpolymers The weight per cent of termonomer in various commercial ethylene terpolymers was determined by a time averaging N M R technique. T h e results are compared with those obtained by two iodine monochloride methods. A. G. ALTENAU, L. M. HEADLEY, C. 0. JONES, and H. C. RANSAW, The Firestone Tire & Rubber Company, Central Research Laboratories, Akron, Ohio 44317 Anal. Chem., 42, 1280 (1970)
(1970) Spectrophotometric Determination of Sulfur Dioxide
Identification of Sulfonic Acids and Sulfonates by Mass Spectrometry Methods of conversion of involatile sulfonic acid and sulfonate derivatives of organic compounds to the volatile methyl esters suitable for mass spectrometric analysis are presented, together with typical examples of structural analysis of organic methyl sulfonates. A. HEYWOOD, A. MATHIAS, and A. E. WILLIAMS, Imperial Chemical Industries Limited, Dyestuffs Division, Blackley, Manchester, England Anal. Chem., 42, 1272 (1970)
The Stephens-Lindstrom spectrophotometric method has been modified and the nature of the reaction of SO2 with iron(III) in the presence of phenanthroline elucidated. Amounts of SOa in the range of 2 to 30 jug have been determined using 4-cm cells. AMIR ATTARI, T. P. IGIELSKI, and BRUNO JASELSKIS, Department of Chemistry, Loyola University, Chicago, III. Anal. Chem., 42, 1282 (1970)
Radiopolarography of Thallium Catalytic Effect of Iron on Oxidation of Plutonium by Hydrogen Peroxide In the presence of iron, hydrogen peroxide oxidizes plutonium partially to the hexavalent state instead of reducing it quantitatively to the quadrivalent state as otherwise occurs in a sulfate system. CLAUDE W. SILL, DONALD R. PERCIVAL, and RODGER L. WILLIAMS, Health Services Laboratory, U. S. Atomic Energy Commission, Idaho Falls, Idaho Anal. Chem., 42, 1273
R. A. CULP and A. F. FINDEIS, Department of University of Alabama, University, Ala. 35486
Chemistry,
Anal. Chem., 42, 1285
(1970)
(1970) Determination of Water in Ion-Exchange Resins: Anion Exchange Resins
Selective Response of Photographic Emulsions to Ion Structure A direct comparison is presented regarding the relative sensitivity of photographic emulsions to ions of different structure, size and composition. PAUL VOUROS, D. M. DESIDERIO, J. V. M. LEFERINK, and JAMES A. McCLOSKEY, Institute for Lipid Research, Baylor College of Medicine, Houston, Texas 77025 Anal. Chem., 42, 1275
Comparisons of radiopolarographic and polarographic data show that the radioactivity associated with the mercury drops is a combination of the diffusion controlled process and specific adsorption or post-electrolysis that occurs after the drop has detached from the D M E .
(1970)
The drying, Karl Fischer, and P M R methods of water determination in several cation and anion exchangers have been examined. The Karl Fischer titration method is satisfactory in all the cases studied. The limitations of the drying and P M R techniques have been pointed out. H. D. SHARMA and N. SUBRAMANIAN, Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada Anal. Chem., 42, 1287 (1970)
ANALYTICAL CHEMISTRY, VOL. 42, NO. 11, SEPTEMBER 1970 · 19 A
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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