AC BRIEFS

E. W. HOBART, R. STEVENSON, and S. KALLMANN, Ledoux &. Company, Teaneck, N. J. 07666. Anal. Chem. 39, 1659 (1967). Electrochemical Masking with ...
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Effects of Adsorption of Electroactive Species in Stationary Electrode Polarography T h e effect of t h e adsorption of electroactive materials in stationary electrode polarography lias been, studied on a quantitative basis. A numerical m e t h o d t o solve t h e integral equations obtained from t h e b o u n d a r y value problems and t h e resulting d a t a have made i t possible t o characterize quantitatively t h e adsorption parameters of the system. ROBERT H . W O P S C H A L L and IRVING SHA1N, Chemistry Department, University of Wisconsin, Madison, Wis. A n a l . Chem. 39, 1514 (1967)

Adsorption Characteristics of the Methylene Blue System Using S t a t i o n a r y Electrode Polarography T h e theory of stationary electrode polarography in cases in which t h e product of t h e electrode reaction is strongly adsorbed h a s been tested b y a study of t h e reduction of methylene blue. Isotherm parameters for t h e adsorbed product (leuco methylene blue) have been calculated. ROBERT H . W O P S C H A L L and IRVING SHA1N, Chemistry Department, University of Wisconsin, Madison, Wis.

HIGHLIGHTS TECHNICAL

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Polarographic Study of Complexes of C o p p e r ( l l ) Ion w i t h Ammonia and Various Ethyl, Ethanol, and Ethylethanolamines An improved technique for determining from polarographic data, t h e formulas and formation constants of copper(I) a n d copper(II) complexes with, an amine a n d hydroxide ion as ligands is reported. Statistical methods used are adapted to a high speed digital computer. J O H N F. FISHER and JAMES L. HALL, Department of Chemistry, West Virginia University, Morgantown, W . Va. 26506 Anal. Chem. 39, 1550 (1967)

Analytical Applications of Kalousek Polarography Two of t h e three Kalousek polarographic techniques are examined for applicability as analytical methods emphasizing t h e capability to distinguish readily between reversible and irreversible reactions at t h e droping mercury electrode. W . F. KINARD, R. H. PHILP, and R. C. PROPST, Savannah River Laboratory, E. I. du Pont de Nemours & Co., Aiken, S. C. 2980I Anal. Chem. 39, 1556 (1967)

Anal. Chem. 39, 1527 (1967)

Adsorption Effects in Stationary Electrode Polarography w i t h a Chemical Reaction Following Charge Transfer A study to determine t h e applicability of adsorption models to_ systems with coupled chemical reactions has been carried o u t with t h e azobenzene-hydrazobenzene system as an example of a succeeding chemical reaction where t h e reactant is known to b e adsorbed. ROBERT H . W O P S C H A L L and IRVING S H A I N , Chemistry Department, University of Wisconsin, Madison, Wis.

Potentiometric Study of Base Strengths in the Binary Solvent, A c e t i c Acid—p-Dioxane A study to determine what solvent influences are exerted b y _ p-dioxane upon t h e potentiometrically measured basicity of nitrogen bases and periodic group La acetates. ORLAND W . KOLLING and D. A L L A N GARBER, Chemistry Department, Southwestern College, Winfield, Kan. 67156 Anal. Chem. 39, 1562 (1967)

A n a l . Chem. 39, 1535 (1967)

High-Precision Coulometric lodimetry The Mercury C o a t e d Tubular Platinum Electrode A reproducible m e t h o d for preparing a mercury coated tubular platinum electrode ( M T P E ) , defining voltage ranges over which it, m a y be used in nine supporting electrolytes, and evaluating t h e stability of the electrode for electroanalytical measurement is reported.

Reported are conditions under which iodine can be electrochemically generated from K I solutions with 99.9999+% current efficiency. N B S Standard Reference Material 83c, arsenic trioxide, has been analyzed based on these conditions. T h e precision of this method of analysis is 0.003% for 0.5-gram samples of As 2 0 3 .

T. O. OESTERLING and CARTER L. OLSON, College of Pharmacy, The Ohio State University, Columbus, Ohio

GEORGE MARINENKO and J O H N K. TAYLOR. Institute for Materials Research, Division of Analytical Chemistry, National Bureau of Standards, Washington, D. C. 20234

A n a l . Chem. 39, 1543 (1967)

Anal. Chem. 39, 1568 (1967)

Chronoamperometry a t Tubular Mercury-Film Electrodes Currents of experimental chronoamperograms of ion-ion and i o n - a m a l g a m reductions obtained a t open-ended M T P l i s of finite length were compared with a derived expression of t h e current-time equation for quiet solution electrolysis. T h e influence of e n d diffusion a n d convection was studied.

Conductometric Analysis of Binary Amine Mixtures Reacting via A p p a r e n t Fractional O r d e r Kinetics Reaction orders, nt, a n d rate constants of pure amines reacting with methyl iodide in various media are reported as well as results obtained for the analyses of several mixtures of amines reacting via fractional-order kinetics.

T. O. OESTERLING and CARTER L. OLSON, College of Pharmacy, The Ohio State University, Columbus, Ohio

RONALD A . GREINKE and HARRY B. MARK, Jr., Department of Chemistry, University of Michigan, Ann Arbor, Mich. 48104

A n a l . Chem. 39, 1546 (1967)

Anal. Chem. 39, 1572 (1967) VOL. 39, NO. 13, NOVEMBER 1967 ·

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AC BRIEFS C r i t i c a l Experimental Evaluation of Limitations of G r a p h i c a l Extrapolation and the Roberts and Regan Differential Reaction Rate Methods. Effects of Ratio of Rate Constants and Composition of Mixture on Accuracy Binary mixtures of amines reacting with t h e reagent, m e t h y l iodide, are analyzed employing two differential r e ­ action rate methods, G E M a n d M E R , in order to define t h e limitations a n d point of failure of t h e m e t h o d s b y means of actual experimental analysis. RONALD A. GREINKE and HARRY B. MARK, Jr., Department of Chemistry, University of Michigan, Ann Arbor, Mich. 48104

Flame Spectrophotometric Determination of Phosphorus O p t i m u m excitation flame conditions of t h e atomic spec­ t r u m of phosphorus are reported. T h e analytical poten­ tialities of b o t h atomic and molecular spectra for t h e oxyacetylene, oxyhydrogen, and air-hydrogen flames are also evaluated. T h e method has been applied t o repre­ sentative biological materials. R. K. SKOGERBOE, A N N S. GRAVATT, and G . H . MORRISON, Department of Chemistry, Cornell University, Ithaca, Ν. Υ. Anal. Chem. 39, 1602 (1967)

Anal. Chem. 39, 1577 (1967)

Nuclear Magnetic Resonance Spectrometry of Methyl-1-lndanones T h e relative geometry of indanones a n d t h e corresponding indanol derivatives has been studied a n d the stereochem­ istry determined by conversion of t h e indanones t o indanols with sodium borohydride and b y consideration of the anisotropy effects associated with t h e system. HARRY A G A H I G I A N , H O W A R D PLANT, and GEORGE D. VICKERS, Olin Mathieson Chemical Corp., New Haven, Conn., and JAMES VANDERVEEN, Department of Chemistry, Stevens Institute of Technology, Hoboken, N. J .

Determination of N i t r i t e Ion Using the Reaction w i t h p-Nitroaniline and Azulene A purplish pink azo dye which nitrite forms with p-nitroaniline and azulene has a molar absorptivity of 5.2 χ 10* mole" 1 cm" 1 measured at 515 ναμ. T h e sensitivity of t h e m e t h o d is 0.22 μ-g of nitrite. Ε. Ε. GARCIA, Nuclear Technology Department, General Electric Co., Pleasanton, Calif. Anal. Chem. 39, 1605 (1967)

Anal. Chem. 39, 1583 (1967)

Structure Determination o f Substituted Benzenes by Proton Magnetic Resonance. An Empirical Treatment of Substituent Effects and Their Utility in Predicting Chemical Shifts Presented is a scheme for rapidly predicting t h e ring pro­ ton chemical shifts of certain substituted benzenes. Of 543 possible unique chemical shifts in a given set of sub­ stituted benzenes, 171 have been observed and predicted to within 0.02 p p m . I t is claimed t h a t all of t h e 372 r e ­ maining shifts can b e predicted t o good accuracy with t h e use of 51 empirical constants.

Determination of Beryllium and Titanium w i t h Benzoylacetanilide Benzoylaeetanilide precipitates beryllium, BeCCisHsOaN)», in hot, nearly neutral solutions, and an orange-yellow complex with titanium,. TÎOCCIBHIISOBNÎS, from acidic solutions, for gravimetric determination of Be and T i . Spectrometric determination of T i complex in chloroform showed m a x i m u m absorbance a t 360-5 τημ. AJIT K. SARKAR and JYOTIRMOY DAS, Department of Chem­ istry, The University of Burdwan, W . Bengal, India Anal. Chem. 39, 1608 (1967)

J O H N J . R. REED, Esso Research and Engineering Co., Baytown Chemicals Research Laboratory, Baytown, Texas Anal. Chem. 39, 1586 (1967)

Determination of Gadolinium and Europium in Their Tungsten Bronzes by High Energy Photon A c t i v a t i o n and Computer Resolution of Gamma-Ray Spectra A procedure which utilizes t h e electron synchrotron as t h e irradiation source and relies on a linear least-squares fit­ ting program for data analysis for the nondestructive quantitative determination of G d and E u is reported. PETER J . M. KORTHOVEN, MARGARET A. WECHTER, and ADOLF F. VOIGT, Institute for Atomic (Research and Department of Chemistry, Iowa State University, Ames, Iowa 50010

Effect of Tailing on the Separability of Mixtures in Gas Chromatography T h e t h eo r y of tailing of kinetic origin as it effects peak mixture separability is evaluated. A detailed analysis of a particular tail profile is compared t o its description b y Gidding's expression of tailing of kinetic origin. KAZUHARU TAKIZAWA, TERUYA SHIMBASH1, and TADAO SHIBA, Department of Chemical Engineering, Tokyo Institute of Technology, Tokyo, Japan Anal. Chem. 39, 1612 (1967)

Anal. Chem. 39, 1594 (1967)

Emission Photometry of Picomoles of Calcium, Magnesium, and O t h e r Metals

Gas Chromatographic Separation of Polar Isotopic Molecules

T h e helium glow excitation technique has been used to measure minor metallic constituents in nanoliter volumes of fluid, and sensitivities of 10 elements have been o b ­ tained.

A study of G C separations of alcohols, acetone, and chloro­ form from their deuterated molecules is reported. Differ­ ences of enthalpy and e n t r o p y related to t h e chromato­ graphic process for alcohols and acetone have been deter­ mined.

GERALD G . VUREK, Laboratory of Technical Development, Na­ tional Heart Institute, Bethesda, M d . 20014

G. PAOLO CARTONI, ARNALDO LIBERTI, and ALBERTO PELA, Istituto Chimica Analitica, Universita Napoli, Naples, Italy

Anal. Chem. 39, 1599 (1967)

Anal. Chem. 39, 1618 (1967)

Circle No.111on Readers' Service Card

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Determination of Alkylpolynitrates by Electron C a p t u r e Gas C h r o m a t o g r a p h y — Application t o A i r Pollution

Lithium Aluminum Di-n-Butyl Amide as a Direct Acid-Base T i t r a n t f o r Q u a n t i t a t i v e Determination of Silanol A general m e t h o d for t h e determination of silanol a n d water has been developed and applied t o study a wide variety of silanol-containing materials. Potential interfering reactions have been studied in detail, a n d t h e visual end point h a s been confirmed b y potentiometric titration.

A m e t h o d of air gas chromatographic analysis b y electron capture detection has been applied to t h e determination of three industrial alkylpolynitrates : E G D N , P G D N , and NG.

Michigan

ETTORE C A M E R A and D A R I O P R A V I S A N I . Research D e p t . o f Dr. I n g . M . Biazzi S. Α . , D i n a m i t e S.p.A., M e r e t o d i T o m b a , Udine, Italy

A n a l . C h e m . 3 9 , 1623 ( 1 9 6 7 )

A n a l . C h e m . 3 9 , 1645 ( 1 9 6 7 )

G E N E E. K E L L U M a n d K E N N E T H L. U G L U M , C e n t r a ! University, M o u n t Pleasant, M i c h .

Titration of Bases in Acetonitrile Reported is a study of the visual, spectrophotometric, p o tentiometric, and conductometric titration in A N of u n charged a n d of univalent anion bases with perchloric acid. I. M . K O L T H O F F , M . K. C H A N T O O N I , Jr., a n d S A D H A N A B H O W M I K , School of Chemistry, University of M i n n e s o t a , M i n neapolis, M i n n . 5 5 4 5 5 A n a l . C h e m . 3 9 , 1627 ( 1 9 6 7 )

Precipitation of Beryllium from Homogeneous Solution by Decomposition of an Acetylacetone Species in Basic Solution A relatively soluble species, formed when a ratio of b e ­ tween one and two moles of acetylacetone t o one of beryllium is maintained, holds beryllium in solution in quite basic media. Upon heating, beryllium hydroxide precipitates from homogeneous solution producing a more easily filterable precipitate. W A L T E R G . B O Y L E and C H A R L E S H . O T T O , Jr., Lawrence Ra­ d i a t i o n Laboratory, University of C a l i f o r n i a , Livermore, C a l i f .

Radiochemical Separations by Adsorption on Manganese Dioxide

A n a l . C h e m . 3 9 , 1647 ( 1 9 6 7 )

T h e fixation of a large n u m b e r of different ionic species on M n 0 2 has been studied b y batch equilibrium and passage through chromatographic columns. Some practical applications to radiochemical separations and activation analysis have been tested. C A R L A B I G L I O C C A , F R A N C O G I R A R D ] , JULES PAULY, and E N R I C O S A B B I O N I , Chemistry D e p a r t m e n t , C C R Euratom, Ispra, and S A N D R O M E L O N I and A U G U S T O P R O V A S O L I , L a b o r a t o r y di Radiochimica d e l l ' l s t i t u t o d i C h i m i c a G é n é r a l e d e l i ' U n i v e r s i t a di Pavia, Pavia, I t a l y A n a l . C h e m . 3 9 , 1634 ( 1 9 6 7 )

X-Ray Diffraction Determination of Dialkyldimethylammonium-Urea Adduct in Urea A m e t h o d for determining the a m o u n t of a dialkyl qua­ ternary ammonium-urea adduct in t h e presence of excess urea b y measuring t h e intensity of a hexagonal urea dif­ fraction maximum is reported. L. M . C H A M B E R S , The Procter a n d G a m b l e C o . , C i n c i n n a t i , O h i o 45217 A n a l . C h e m . 3 9 , 1650 ( 1 9 6 7 )

Notes Determination of T r a c e Impurities in M e r c u r y and Some High Purity Acids by Spark Source Mass Spectrometry

Q u a n t i t a t i v e Analysis of Volatile F a t t y Acids in Aqueous Solution by Gas Chromatography

Spark source mass spectrometry has been applied as a highly sensitive and rapid technique t o t h e trace analysis of high purity liquids. Specific application results are reported for mercury, phosphoric acids, a n d nitric acid analyses. C L A U D E CHERRIERi and M I T H A T N A L B A N T O G L U , Centre d e Recherches d e la C r o i x d e Berny, Sociata d e Produits Chimiques, P e c h i n e y - S a i n t - G o b a i n , 9 2 . A n t o n y , France

A simple and reliable method for t h e separation and quan­ tification of aqueous solutions of short chain normal and iso acids b y gas chromatography using columns contain a new packing material, Porapak Q, is reported. VAIDYANATH MAHADEVAN isotope Service, Minneapolis Minn. 55417

and L A U R E N S T E N R O O S , Radio­ Veterans H o s p i t a l , M i n n e a p o l i s ,

A n a l . C h e m . 3 9 . 1652 ( 1 9 6 7 )

A n a l . C h e m . 3 9 , 1640 ( 1 9 6 7 )

Spectrophotometric Determination of Iron W i t h 2. 4-Dihydroxypropiophenone Oxime Ferric iron has been found to form a stable purple colored complex with 2, 4-dihydroxypropiophenone between p H?2.0 and 3.0 which h a s a molar absorptivity of 22.50 X 10 a t 510 rmt. M . H . G A N D H I and M A H E N D R A N . D E S A I . C h e m i s t r y ment, G u j a r a t University, A h m e d a b a d - 9 , India

Determination of Vinyl Unsaturation in Organic Compounds w i t h Mercuric A c e t a t e An efficient and accurate method for determining vinyl unsaturation in organic compounds is applied to t h e d e ­ termination of styrènes, cyclohexene, allyl alcohol, and methally alcohol.

Depart-

R O L A N D P. M A R Q U A R D T and E. N . L U C E , The Dow C h e m i c a l Co., Midland, Mich. 48640

A n a l . C h e m . 3 9 , 1643 ( 1 9 6 7 )

A n a l . C h e m . 3 9 , 1655 ( 1 9 6 7 )

-Circle No. 208 on Readers' Service Card

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AC BRIEFS Mechanism of the Reaction of 4-Amino-6-Chlorom-Benzenedisulfonamide w i t h Nitrous A c i d

Determining the True Mid-Point of α Count Rate Observed in Radionuclear Counting

T h e reaction proceeds i n t w o steps, yielding first a sulfamoylbenzenesulfonic acid derivative, t h e n a thiatriazine derivative which r a p i d l y reverts t o t h e corresponding diazonium derivative i n t h e presence of water.

A D O N A. GORDUS, Department of Chemistry, The University of Michigan, Ann Arbor, Mich. 48J04 Anal. Chem. 39, 1672 (1967)

TIBOR URBANYI, M I R I A M PAGLIERY, and C. R. REHM, Re­ search Department, C1BA Pharmaceutical Co., Summit, N. J . Anal. Chem. 39, 1656 (1967) A p p l i c a b i l i t y of L o w - T e m p e r a t u r e Ignition M e t h o d f o r Determining C a r b o n in Various A l k a l i M e t a l s T h e low t e m p e r a t u r e ignition m e t h o d r e p o r t e d is suitable for determining as little as 1 /tg of carbon a n d h a s b e e n applied to Li, K , N a K , Cs, a n d R b . E. W . HOBART, R. STEVENSON, and S. KALLMANN, Ledoux & Company, Teaneck, N. J . 07666

Aids for Analytical Chemists H e a t e d I n f r a r e d C e l l f o r Investigation of Solids in a Controlled Atmosphere THEODORE WYDEVEN and MARK LEBAN, Ames Research Cen­ ter, NASA, Moffett Field, Calif. 94035 Anal. Chem. 39, 1673 (1967)

Anal. Chem. 39, 1659 (1967) Electrochemical Masking w i t h an Adsorbed M e t a l Complex. Determination of S i l v e r - M e r c u r y Mixtures A n adsorbed lead layer selectively penetrable b y different ions is used for determining A g - H g ( I I ) mixtures based on an a p p r o p r i a t e analysis of t h e morphology of a single p o larographic current—time curve. ROYCE W . MURRAY and R. L. McNEELEY, Department of Chemistry, University of North Carolina, Chapel Hill, N. C . 27514

Simple Effluent S p l i t t e r f o r Measurement of Electron C a p t u r e / F l a m e Ionization Response Ratios WALTER L. ZIELINSKI, JR., LAWRENCE FISHBEIN, and RICH­ ARD O . T H O M A S , Bionetics Research Laboratories, Inc., Falls Church, Va. Anal. Chem. 39, 1674 (1967)

Ana!. Chem. 39, 1661 (1967) Analysis and Distillation of Propylene C a r b o n a t e T h e purification of propylene carbonate b y fractional dis­ tillation is r e p o r t e d using gas—solid c h r o m a t o g r a p h y as t h e p r i m a r y analytical t e c h n i q u e .

Detection of M e r c a p t a n s by the Weisz Ring Oven Method M. H . SAXE, 64 Williams Road, Lexington, Mass.

02173

Anal. Chem. 39, 1676 (1967)

RAYMOND J. JASINSKI and SUSAN KIRKLAND, Tyco Laborato­ ries, Inc., Waltham, Mass. 02154 Anal. Chem. 39, 1663 (1967) P r e p a r a t i o n of M e t h y l Esters of Amino Acids f o r Gas C h r o m a t o g r a p h y Using Dimethyl Dodecanedioate as an Internal S t a n d a r d

Correspondence An O p t i c a l l y Transparent Thin Layer Electrochemical C e l l

MILDRED GEE, Western Regional Research Laboratory, Agricul­ tural Research Service, U. S. Department of Agriculture, Albany, Calif. 94710 Anal. Chem. 39, 1677 (1967)

ROYCE W . MURRAY, W . R. HEINEMAN, and G . W . O ' D O M , Department of Chemistry, University of North Carolina, Chapel Hill, N. C. 275I4 Anal. Chem. 39, 1666 (1967) Frumkin Double-Layer Corrections A p p l i e d t o the Heterogeneous Rate Constant f o r C d ( l l ) Evaluated by A l t e r n a t i n g C u r r e n t Polarography J, D. McLEAN and ANDREW TIMNICK, Department of Chem­ istry, Michigan State University, East Lansing, Mich. 48823

Double-Path Q u a r t z M i c r o - C e l l f o r Solutions of Unknown Absorbance DENIS M. ABELSON, Department of Medicine, Graduate Hospital of the University of Pennsylvania, Philadelphia, Pa. 19146 Anal. Chem. 39, 1679 (1967)

Anal. Chem. 39, 1669 (1967) Kinetics and Mechanism of Extraction of C o b a l t ( I I ) w i t h Substituted Diphenylthiocarbazones

A Simple A d a p t a t i o n t o C o n v e r t Commercial A u t o m a t i c T i t r a t o r s t o Automatic Microtitrators

J O O N S. O H and HENRY FREISER, Department of Chemistry, University of Arizona, Tucson, Ariz. 85721

MARK L. LYNDRUP, Department of Chemistry, Northwestern Uni­ versity, Evanston, III.

Anal. Chem. 39, 1671 (1967)

Anal. Chem. 39, 1680 (1967) VOL. 39, NO. 13, NOVEMBER 1967 ·

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