AC BRIEFS

The end point is detected ampero- metrically. ..... I. ElSS and PAUL GIESECKE, AmericanCyanamid Co., Stamford,. Anal. Chem ... South Charleston,W. Va...
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BRIEFS Highlights of the scientific and technical articles in this issue

Informal Discussion of Electroanalytical Chemistry

Notes on an informal discussion of electroanalytical chemistry are presented. The general topics discussed are: electrochemical techniques, role of the electrode surface, and processes in the solution. W . H. RE1NMUTH, Columbia University, New York, N. Y„ C. N. REILLEY, University of North Carolina, Chapel Hill, N. C , and L. B. ROGERS, Massachusetts Institute of Technology, Cambridge, Mass. Anal. Chem. 3 1 , 1 4 5 0 ( 1 9 5 9 )

Continuous Coulometric Analysis Using a Working Electrode of Predetermined Potential

A new continuous coulometric analysis is described in which the working electrode not only causes the reaction but effects the necessary current control. The method is applicable for measuring electro-oxidizable or reduc­ ible substances in flowing stream. E. L. ECKFELDT, Leeds & Northrup Co., Philadelphia 4 4 , Pa.

Rapid Polarographic Determination of LowConcentrations of Silver in the Presence of Interfering Elements

A rapid polarographic procedure for determining low concentrations of silver in the presence of various ions is developed. The method uses an ammoniacal support­ ing electrolyte and a manual polarograph. Higher ac­ curacy is obtained than in conventional polarographic procedures. YECHESKEL ISRAEL and AVRAHAM V R O M E N , Israel Mining Industries, H a i f a , Israel Anal. Chem. 3 1 , 1 4 7 0 ( 1 9 5 9 )

Rapid Polarographic Determination of Low Concentrations of Mercuric Ion

Low concentrations of mercuric ion are determined by a rapid polarographic procedure. Mercuric ion is best determined with a manual polarograph, with the galva­ nometer deflection measured at the limiting plateau. Lowest detectable concentration was 5 X 10 "l millimole.

Anal. Chem. 3 1 , 1 4 5 3 ( 1 9 5 9 ) YECHESKEL ISRAEL, Israel Mining Industries, Haifa, Israel Anal. Chem. 3 1 , 1 4 7 3 ( 1 9 5 9 )

Coulometric Titration of Manganese with Electrogenerated V a n a d y l Ion

A coulometric titration procedure for manganese uses electrogenerated vanadyl ion as the titrant. Prior to titration the manganous ion is converted to permanganate with argentic oxide. The end point is detected amperometrically. D. G . DAVIS, Georgia Institute of Technology, Atlanta 1 3 , G a . Anal. Chem. 3 1 , 1 4 6 0 ( 1 9 5 9 )

Internal Electrolysis-Coulometric Method for Determination of Small Quantities of O x y g e n . Application to Individual Samples

A method for determining small amounts of free oxygen in gases or liquids involves an internal electrolysis and coulometric technique. No interference is encountered with hydrogen or hydrogen peroxide. The method is applied to studies in radiation chemistry, reactor water, steam and gas studies, and corrosion evaluation research. W . G . KNAPP, Argonne National Laboratory, Lemont,lll. Anal. Chem. 3 1 , 1 4 6 3 ( 1 9 5 9 )

Polarography of Mixtures. Simultaneous Determination of Iron and Nickel

Controlled-Potential and Derivative Polarograph

Detailed discussions are offered on the various features of controlled-potential and derivative polarography. Controlled-potential polarography is especially suitable for high resistance media. Certain polarograms are presented that illustrate the advantages of controlledpotential over conventional polarography. M. T. KELLEY, H. C. JONES, and D. J. FISHER, O a k Ridge National Laboratory, O a k Ridge, Tenn. Anal. Chem. 3 1 , 1 4 7 5 ( 1 9 5 9 )

Polarographic Determination of Pentaerythritol Trinitrate in the Presence of Nitroglycerin

A polarographic method is described for determining pentaerythritol trinitrate in nitrocellulose propellants. The sample may contain nitroglycerin, nitrocellulose, 2-nitrodiphenylamine, and dibutyl phthalate as major components. Interference due to heavy metal salts is negligible. W . M. AYRES and G . W . LEONARD, U. S. N a v a l Ordnance Test Station, China Lake, Calif. Anal. Chem. 3 1 , 1 4 8 5 ( 1 9 5 9 )

Spectrophotometric Determination Uranium-Rhodium Alloys

of Rhodium

in

Polarographic methods are described for the determina­ tion of iron and nickel in solution without the necessity of separation. The methods employ the 5-sulfosalicylic acid complex of iron (III) in supporting electrolytes of either ammoniacal or pyridinical composition.

A rapid spectrophotometric method is devised for de­ termining rhodium in uranium-rhodium alloys. A sep­ aration technique is not necessary; the sample is reacted with a solution of stannous chloride in hydrochloric acid and the red color measured at 520 ταμ.

S. L. PHILLIPS and EVAN M O R G A N , Internal Business Machines Corpora­ tion, Poughkeepsie, Ν . Υ. Anal. Chem. 3 1 , 1 4 6 7 ( 1 9 5 9 )

R. D. GARDNER and A. D. HUES, Los Alamos Scientific Laboratory, Los Alamos, Ν . Μ. Anal. Chem. 3 1 , 1 4 8 8 ( 1 9 5 9 )

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BRIEFS Determination of Radioactive Strontium Low concentration of isotopes strontium-89 and strontium-90 are determined in various environmental sam­ ples. Techniques for removal of interfering substances such as calcium, barium, radium, polyvalent metals, and phosphates are described. A. S. G O L D I N , R. J. VELTEN, and G. W . FRISHKORN, Robert A. Taft Sanitary Engineering Center, Cincinnati 2 6 , Ohio Anal. Chem. 3 1 , 1 4 9 0 ( 1 9 5 9 )

Ion Exchange Chromatography of A m i n o Acids. Semiautomatic Method of Operation with Cationic Exchange Resin Columns A c h r o m a t o g r a p h i c separation p r o c e d u r e is described for amino acids found in protein hydrolyzates. O n e column is employed, packed with a sulfonated polysty­ rene cationic exchange resin, along with a fraction col­ lector which automatically controls changes of tempera­ ture and buffer solutions. P. B. HAMILTON and R. A. ANDERSON, Alfred I. du Pont Institute of the Nemours Foundation, Wilmington 9 9 , Del. Anal. Chem. 3 1 , 1 5 0 4 ( 1 9 5 9 )

Analysis of Thin Metal Films by Neutron Activation N e u t r o n activation analysis is applied to the determina­ tion of very thin metal films deposited o n glass. Leach­ ing contaminants, incomplete isotopic exchange, and incomplete decontamination are the factors affecting the accuracy. Standard deviation for the p r o c e d u r e is ±0.5%. B. A. T H O M P S O N , General Electric Co., Schenectady, Ν. Υ.

Detection of Trace Constituents by Gas Chromatography. Analysis of Polluted Atmosphere

Anal. Chem. 3 1 , 1 4 9 2 ( 1 9 5 9 )

A gas chromatographic technique is described for analy­ sis of polluted atmosphere, determining components present in the r a n g e of a few parts p e r h u n d r e d million. Quantitative estimation is made by measuring the area under the c h r o m a t o g r a p h i c peak. T h e method is ap­ plicable to a large variety of organic c o m p o u n d s . Visual Titrations in Nonaqueous Solvents w i t h Benzanthrone as Internal Indicator

P. S. FARRINGTON, R. L. PECSOK, R. L. MEEKER, and T. J. O L S O N , University of California, Los Angeles, Calif.

Benzanthrone is employed as a useful indicator for the detection of the neutralization p o i n t of Lewis acids with tertiary bases in polar and n o n p o l a r solvents. T h e reversibility of t h e indicator is illustrated in several cases.

Anal. Chem. 3 1 , 1 5 1 2 ( 1 9 5 9 )

R. C. PAUL, JASWANT S I N G H , and S. S. SANDHU, Panjab University, Hoshiarpur, India Anal. Chem. 3 1 , 1 4 9 5 ( 1 9 5 9 )

Analysis of lonones and Methylionones by GasLiquid Partition Chromatography Thermometric Titration of Acids in the Presence of Hydrolyzable Cations "Free acid" in acid solutions containing the hydrolyzable ions z i r c o n i u m ( I V ) , u r a n i u m ( V I ) , c o p p e r ( I I ) , thorium(IV), and chromium (III) is determined by an automatic, thermometric titration in which a thermistor is used to indicate the temperature change of the solutions. F. J. MILLER and P. F. T H O M A S O N , O a k Ridge National Laboratory, O a k Ridge, Tenn. Anal. Chem. 3 1 , 1 4 9 8 ( 1 9 5 9 )

Countercurrent Distribution of Some Aromatic Hydrocarbons T h e resolving p o w e r of/3,/3'-oxydipropionitrile and isooctane is studied in a countercurrent distribution tech­ nique for separation and identification of aromatic hydro­ carbons. Partition coefficients for 24 aromatic hydro­ carbons are determined and the distribution of a syn­ thetic mixture of naphthalenes is made for performance studies of the solvents. Y.-C. C H A N G and R. D. W O T R I N G , Bureau of Mines, Morgantown, W . Va. Ana!. Chem. 3 1 , 1 5 0 1 ( 1 9 5 9 !

A conventional gas chromatographic unit and a packed column of Apiezon L o n Celite are combined to resolve the isomeric composition of ionones and methylionones. T h e rapid method is applicable to commercial perfume grade mixtures. R. O . CR1SLER and C. L. BENFORD, Procter & Gamble Co., Cincinnati 3 1 , Ohio Anal. Chem. 3 1 , 1 5 1 6 ( 1 9 5 9 )

Mass Spectrometer IBM 6 5 0

Data

Reduction

Program

for

A p r o g r a m for mass spectrometer data reduction is written for the basic IBM 6 5 0 electronic computer using the iterative method of Gauss-Seidel. T h e system is flexible, convenient, and accurate and does not require a k n o w l e d g e of mass spectrometry by the 6 5 0 operator. J. M. GILLETTE, Tidewater Oil Co., Los Angeles 5, Calif. Anal. Chem. 3 1 , 1 5 1 8 ( 1 9 5 9 !

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BRIEFS Quantitative Determination of the Four Major Phases of Portland Cement by Combined X - R a y and Chemical Analysis

A combination of x-ray and chemical analysis is employed for evaluating the quantities of the four major compounds in portland cement. Alite, belite, tricalcium aluminate, and ferrite are analyzed and the results compared to es­ timations obtained by the Bogue method and micro­ scopical analysis. L. E. COPELAND, STEPHEN BRUNAUER, D. L. KANTRO, E. G. SCHULZ and C. H. WEISE, Portland Cement Association Research and Develop­ ment Laboratories! Skokie, III. Anal. Chem. 3 1 , 1 5 2 1 ( 1 9 5 9 )

Analysis by Phosphor Poisoning

A new analytical method is developed based on the ex­ ternal poisoning effects of certain heavy metals on a type of silver-activated cadmium sulfide phosphor. The mechanism involves the displacement of cadmium by the poison metal resulting in an opaque layer at the surface of each phosphor particle. Analysis is not affected by sample volume, pH, and temperature. ARTHUR BRADLEY and N. V. SUTTON, Associated Nucleonics, Inc., G a r d e n City, N.Y. Anal. Chem. 3 1 , 1 5 5 4 ( 1 9 5 9 )

Colorimetric Determination of Organic Peroxides High Mass Spectrometry. Propylene Polymer, Alkylated Benzene, a n d Wax Analysis

Improvement of instrumental and operating techniques for high mass spectrometry affords a wider range of applicability. Quantitative methods are presented for the analysis of propylene polymers, alkylated benzenes, and petroleum waxes. R. A. B R O W N , D. J. SKAHAN, V. A. CIRILLO, and F. W . MELPOLDER, The Atlantic Refining Co., Philadelphia, Pa.

A simple and sensitive colorimetric method for the de­ termination of organic peroxides employs benzoyl leuco methylene blue as the reagent. In a benzene— trichloroacetic acid solution it reacts to give the char­ acteristic methylene blue color, the transmittance of which is measured at 662 πΐμ. M. I. EISS and PAUL GIESECKE, American Cyanamid Co., Stamford, Conn. Anal. Chem. 3 1 , 1 5 5 8 ( 1 9 5 9 )

Anal. Chem. 3 1 , 1 5 3 1 ( 1 9 5 9 )

Determination of Boric Oxide in Glass by Pyrohydrolysis Separation High Resolution Infrared Spectra of Steroids in the Carbon-Hydrogen Stretching Region

Structural features of various steroidal sapogenins are identified from details of their C—H stretching spectra. The infrared spectra investigation is conducted in the 3100- to 2 7 5 0-cm. _1 region. All observed bands show a strong dependence on the over-all structure of the mole­ cule. A. M. SMITH, Eastern Regional Research Laboratory, Philadelphia 1 8 , Pa., and C. R. EDDY, Temple University, Philadelphia 2 2 , Pa.

A pyrohydrolysis separation is described for the de­ termination of boric oxide in glass. The sample is mixed with uranium oxide and sodium metasilicate monohydrate in a platinum tube and steam passed over the mixture at high temperature. The boric acid ob­ tained is titrated conventionally. Lead, zinc, and phos­ phorus oxides interfere at certain per cent concentra­ tions. J. P. WILLIAMS, Ε. Ε. CAMPBELL, and T. S. MAGLIOCCA, Coming Glass Works, Corning, N.Y. Anal. Chem. 3 1 , 1 5 6 0 ( 1 9 5 9 )

Anal. Chem. 3 1 , 1 5 3 9 ( 1 9 5 9 )

X - R a y Powder Diffraction Data of Azoic Coupling Components

X-ray data identifying 15 of the azoic coupling com­ ponents of commercially available Naphthol AS types are presented. The method is valuable because it leads to positive identification and because commercial Naphthol AS types, usually impure, can be analyzed directly without prior preparation. ISIDORE SCHNOPPER, J. O . BROUSSARD, and C. K. LaFORGIA, U. S. Customs Laboratory, New York, Ν. Υ. Anal. Chem. 3 1 , 1 5 4 2 ( 1 9 5 9

Determination of Trace Impurities in Zirconium Metal by a Point-to-Plane Spectrochemical Procedure

Zirconium metal is directly excited with an ignited al­ ternating current arc to determine 1 7 metals in the partsper-million range. This method of production control analysis gives required spectral sensitivity and reproduc­ ibility, and reduces analysis time and opportunity for sample contamination compared with other methods. R. F. FARRELL G. J. HARTER, and R. M JACOBS, Westinghouse Electric Corp., Pittsburgh, Pa. Anal Chem 3 1 , 1 5 5 0 ( 1 9 5 9 1

Determination of V i n y l Ethers and Other Unsaturated Compounds. Modified Mercuric Acetate Procedure

Vinyl ethers and other olefinic unsaturated compounds are determined by a modified methoxymercuration method. The sample is reacted with mercuric acetate in methanol at a low temperature and the acetic acid formed is ti­ trated with alcoholic potassium hydroxide. Wide range application data are presented. J. B. J O H N S O N and J. P. FLETCHER, Union Carbide Chemicals Co., South Charleston, W . V a . Anal. Chem. 3 ) , 1 5 0 3 ( 1 9 5 9 )

Determination of Dichlorodifluoromethane in Fumigation Mixtures with Ethylene Oxide. By Measurement of Thermal Conductivity

A rapid and simple procedure for determining dichloro­ difluoromethane in fumigation mixtures with ethylene oxide is practical for field use. The ethylene oxide is removed and determined separately and the dichloro­ difluoromethane determined by a thermal conductivity method. W . A. AFFENS, E. O. HAENNI, and R. A. FULTON. U. S. Departmen· o< Agriculture, Beltsvilk, M d . Anal Cnem 3 V Ï 5 ô 5 ( 1 9 5 9 »

VOL. 31,

N O . 9, SEPTEMBER

1959



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BRIEFS Reaction of Sodium Chlorite with Various Polysaccharides. Rate Studies and Aldehyde Group Determinations

The oxidation reactions between sodium chlorite and certain polysaccharides are studied under various conditions. Aldehyde contents and degree of polymerization values of polysaccharides are calculated from chlorite results. These results compare favorably with other chemical methods.

Stable Apparatus for High-Frequency Analysis

General consideration of high-frequency analysis and its application are presented. In this type of analysis changes in the sample are detected by the detector circuit as measurable responses of current and frequency shift. Soybean and buckwheat leaves are investigated. KO ISHII, SHOICHI HAYASHI, and SHIZUO FUJIWARA, University of Electro-Communications, Chôfu, Tokyo, Japan Anal. Chem. 3 1 , 1 5 8 6 ( 1 9 5 9 )

H. F. LAUNER and Y O S H I O TOMIMATSU, Western Regional Research Laboratory, Albany, Calif. Anal. Chem. 3 1 , 1 5 6 9 ( 1 9 5 9 )

Arsenic in Naphthas Rapid Determination of Organically Bound Fluorine

A rapid and simple method for determining organically bound fluorine is found to be accurate and precise for a wide variety of organic fluorine compounds. The sample is burned under special conditions and the fluorine photometrically determined by Megregian's procedure. B. Z. SENKOWSKI, E. G . WOLLISH, and E. G . E. SHAFER, Hoffmannl a Roche Inc., Nutley, N . J. Anal. Chem. 3 1 , 1 5 7 4 ( 1 9 5 9 )

Trace Analysis for Total Nitrogen in Petroleum Fractions. Adsorption-ter Meulen Method

Trace amounts of nitrogen compounds in petroleum fractions are quantitatively determined. Large samples are concentrated and the nitrogen compounds adsorbed on a silica gel column. The column is placed in a ter Meulen apparatus where the nitrogen compounds are desorbed. The nitrogen is converted to ammonia and determined by conventional procedures. E. C. SCHLUTER, Jr., Union Oil Co. of California, Brea, Calif.

Chromatographic and colorimetric techniques are combined for the determination of trace amounts of arsenic in naphthas. The arsenic is adsorbed onto silica gel and eluted with acid. It is converted to arsine and reacted with silver diethyldithiocarbamate in pyridine. The adsorbance is measured at 540 πΐμ. G. W . POWERS, Jr., R. L. MARTIN, and F. J. PIEHL, Standard Oil Co. (Indiana), Whiting, Ind., and J. M. GRIFFIN, Utah Oil Refining Co., Salt Lake City, Utah Anal. Chem. 3 1 , 1 5 8 9 ( 1 9 5 9 )

Determination of Microgram Quantities of Arsenic in Naphthas with Oxyhydrogen Burner

The arsenic concentration in naphthas at the parts per billion level is quantitatively determined after sample combustion in a Beckman oxyhydrogen burner. The arsenic is dissolved in sodium hydroxide, converted to arsine, and determined spectrophotometrically with silver diethyldithiocarbamate in pyridine. D. K. ALBERT and LAWRENCE GRANATELLI, American Oil Co., Texas City, Tex. Anal. Chem. 3 1 , 1 5 9 3 ( 1 9 5 9 )

Anal. Chem. 3 1 , 1 5 7 6 ( 1 9 5 9 )

Identification and Differentiation of Sympathomimetic Amines

Separation and Determination of Microgram Amounts of Sulfur

Certain clinical tests are outlined for the identification and differentiation of four sympathomimetic amines. Color reactions and microcrystal formations are employed along with photomicrographs and infrared absorption spectra of the reaction products.

A sensitive method is outlined for the determination of micro amounts of sulfur in uranium trioxide, sodium zirconium fluoride, and hydrofluoric acid. Fusion causes the evolution of sulfur trioxide which is reduced to the dioxide and determined with pararosaniline and form­ aldehyde.

L. G . CHATTEN and LEO LEVI, Department of National Health and W e l f a r e , O t t a w a , Ontario, C a n a d a Anal. Chem. 3 1 , 1 5 8 1 ( 1 9 5 9 )

R. P. LARSEN, L. E. ROSS, and N . M. INGBER, Argonne National Labo­ ratory, Lemont, III. Anal. Chem. 3 1 , 1 5 9 6 ( 1 9 5 9 )

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