AC BRIEFS Highlights
Second Harmonic Alternating Current Poiarog raphy with a Reversible Electrode Process Second harmonic alternating current components arising in a.c. poiarography are investigated quantitatively. Ex perimental data is found to be in agreement with theoreti cal evidence. The study indicates the efficiency with which the capacitive current is eliminated by using second har monic a.c. poiarography. D. E. SMITH and W . H. REINMUTH, Columbia University, New York 27, Ν . Υ. Anal. Chem. 33,482 (1961)
Distortion of Chronopotentiograms from Double Layer and Surface Roughness Effects The effects of surface roughness and double layer capaci tance on chronopotentiometric potential-time curves arc studied. Consideration is given to means of eliminating or minimizing these effects. W . H. REINMUTH, Columbia University, New York 27, Ν. Υ.
of the scientific a n d technical articles in this issue
Determination of Acridine Titration in Acetic Acid
by
Potentiometric
A rapid and convenient titrimetric procedure is devised for the determination of acridine. The sample is dissolved in glacial acetic acid and potentiometrically titrated with perchloric acid. Bases of equal strength interfere. P. R. NAIDU and V. R. KRISHNAN, Sri Venkateswara University, Tirupati, South India Anal. Chem. 33,497 (1961)
Apparatus for High Pressure Poiarography with Application to Poiarography in Liquid Ammonia a t 25° C. A description and application of high pressure poiarogra phy is given, employing a dropping mercury electrode at elevated pressures. The technique is useful for polar ographic studies at temperatures above the normal boiling point, of the solvent. W . B. SCHAAP, R. F. CONLEY, and F. C. SCHMIDT, Indiana University, Bloomington, Ind, Anal. Chem. 33, 498 (1961)
Anal. Chem. 33, 485 (1961)
An Electron Paramagnetic Resonance Investiga tion of Vanadium in Petroleum Oils Automatic Polarograph for Use with Solutions of High Resistance A new automatic polarographic instrument is designed for use with solutions of high electrical resistance. By special arrangement of the pen and t h e drum on the strip-chart plotter, the ili drop is eliminated. T h e apparatus is tested on a wide variety of organic solutions. PAUL ARTHUR, P. A. LEWIS, N. A. LLOYD, and R. K. VANDERKAM, Oklahoma State University, Stillwater, Okla. Anal. Chem. 33,488 (1961)
Poiarography of Uranium(VI)-EDTA
Complexes
An investigation is made into the variables involved in the poiarography of uranium(VI) in E D T A solutions. Particular reference is made to the effect of pH on half wave potential and diffusion current constant. An inter ference-free procedure is outlined. D. G . DAVIS, Louisiana State University in New Orleans, New Orleans 22, La. Anal. Chem. 33, 492 (1961)
Electron paramagnetic resonance procedure is used to de termine the oxidation state of vanadium in petroleum oils. In application the technique indicated a high sensitivity, making possible a rapid and accurate quantitative method for determining vanadium. A. J . SARACENO, D. T. FANALE, and N. D. COGGESHALL, Gulf Research & Development Co., Pittsburgh, Pa. Anal. Chem. 33, 500 (1961)
Determination of Traces of Nickel and Vanadium in Petroleum Distillates. An X-Ray Emission Spectrographic Method Based on a New RapidAshing Procedure An x-ray emission spectrographic procedure is devised us ing a rapid ashing technique for determining traces of nickel and vanadium in petroleum products. The sample is burned in the presence of benzenesulfonic acid and the x-ray intensities of the metals measured directly from the ash. Cobalt is used as an internal standard. J. E. SHOTT, Jr., T. J . GARLAND, and R. O. CLARK, Gulf Re search Development Co., Pittsburgh, Pa. Anal. Chem. 33, 506 (1961)
High Speed Recording Potentiometric T i t r a t o r with Automatic Continuously Variable Rate of T i t r a n t Addition
Prediction of Retention Temperatures in Pro grammed Temperature Gas Chromatography. A Descriptive Equation and Computational Method
A high speed recording potentiometric titrator is devel oped for aqueous and nonaqueous titrations of acids in petroleum products. Titrant flow varies continually dur ing the titrations. T h e instrument is designed to perform titrations in solvents of low conductivity. I t has been used successfully for almost six thousand titrations.
A practical method of calculating predicted retention temperatures is described for temperature programmed gas chromatography. Peak temperatures are predicted rapidly and accurately. T h e equation derived is similar to that of Giddings although the approach is different in some particulars.
J . R. GLASS and E. J . MOORE, Socony Mobil O i l Co., Inc., Paulsboro, N. J . Anal. Chem. 33, 494 (1961)
ROBERT R O W A N , Jr., Esso Research and Engineering Co., Linden, N.J. Anal. Chem. 33, 510 (1961) VOL. 33, NO. 4 , APRIL 1961
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BRIEFS A Vapor Detector Based on Changes in Dielec tric Constant Λ vapor detector apparatus which is sensitive to changes in dielectric constant is used to determine impurities in certain carrier gases. Experimental data verify the theo retical evidence that the principle on which the instrument is constructed is sound. The detector may be applied to li'as chromatographic procedures. J. D. W1NEFORDNER, D. STEINBRECHER, and W . E. LEAR, University of Florida, Gainesville, Fla. Anal. Chem. 33, 515 (1961)
Refined Direct Transmission Photometry of Translucent Sheet Chromatograms. Some As pects of Partition Chromatography Affecting Interpretation of Measurements The assumptions and measurements involved in using direct photometry to determine the concentration of sub stances on paper chromatograms are theoretically investi gated. Instrumentation, galvanometer readings, and the statistical significance of the results are the principal factors studied. J. W . H. LUGG, University of Western Australia, Nedlands, Western Australia EDWARD McEVOY-BOWE, University of Malaya, Sepoy Lines, Singapore 3 Anal. Chem. 33, 535 (1961)
Gas Chromatographic Analysis of Some Volatile Phosphorus Compounds Volatile phosphorus compounds in mixtures are deter mined by gas chromatography using an instrument con structed with inert materials. The thermal conductivity cell contains borosilieate glass and a tantalum filament. The method developed affords a rapid and accurate pro cedure. S. H. SHIPOTOFSKY and H. C. MOSER, Kansas State University of Agriculture and Applied Science, Manhattan, Kan. Anal. Chem. 33, 521 (1961)
A Separation of Beryllium from Aluminum, Trivalent Iron, Yttrium, Cerium, and the Rare Earths by Cation Exchange Chromatography A cation exchange chromatographic procedure using AC! 50W-X8 resin effectively separates beryllium from alum i n u m ( I I I ) , i r o n ( I I I ) , y t t r i u m ( I I I ) , cerium(III), rare earths, and other elements. Single element elution curves are prepared using I.OJV hydrochloric acid as the eluant. F. W . E. STRELOW, South African Council for Scientific and In dustrial Research, Pretoria, South Africa Anal. Chem. 33, 542 (1961)
Double-Column Programmed Temperature Gas Chromatography The chromatograph has a specially designed column block, two completely independent gas flow control systems, and automatic hold, cool, and reset features. E. M. EMERY and W . E. KOERNER, Monsanto Chemical Co., St. Louis 77, Mo. Anal. Chem. 33, 523 (1961)
Copper Binding by Proteins in Alkaline Solution The biuret reaction of alkaline copper tartrate with certain proteins is stoichiometrically investigated. I n all proteins studied, except serum globulin, six peptide nitrogens are bound to each copper. In serum globulin five nitrogens are bound to each copper. A method is proposed for de termining peptide nitrogen by copper binding. R. D. STRICKLAND, M. L FREEMAN, and F. T. GURULE, Veterans Administration Hospital, Albuquerque, N.M. Anal. Chem. 33, 545 (1961)
Electrochromatographic Separation of Silver and Thallium Ions from Each Other and from Mixtures of Various Polyvalent Cations An electrochromatographic procedure is used for the sepa ration of silver or thallium from multieomponent mixtures of polyvalent cations—and for the separation of silver from thallium and other ions. The electrical migrations employed are completed in ammoniacal solutions without crocs contamination. H. H. STRAIN, J. F. BINDER, G. H. EVANS, H. D. FRAME, Jr., and J. J . HINES, Argonne National Laboratory, Argonne, III. Anal. Chem. 33, 527 (1961)
Use of Chlorine in Cation Exchange Separations
Investigation of Nuclear Fast Red Method of Baar for Direct Spectrophotometric Détermina tion of Calcium in Serum, Urine, and Spinal Fluid The Baar method for determining calcium in serum, urine, and spinal fluid is modified. The effects of variations of lime, temperature, concentration of reagents, and interference of nonspecific substances are investigated. T h e modified procedure is an improved nuclear fast red determination of calcium. G. R. KINGSLEY and OZIE ROBNETT, University of California, Los Angeles 24, Calif. Anal. Chem. 33, 552 (1961)
Determination of Calcium and Magnesium Urine by Atomic Absorption Spectroscopy
in
An investigation is made of the effects of chlorinations of ion exchange resins and their consequences in analytical separation procedures. Chlorine uptake by the resin af fects the exchange capacity and moisture content, and increases the weak acid groups.
The calcium and magnesium contents of urine are determined by atomic absorption spectroscopy. For calcium, the sample is diluted with lanthanum or strontium chloride solution, and water is used for diluting the sample for magnesium determination. Solutions are sprayed into an air-acetylene flame and the absorption measured.
W . J . BLAEDEL and E. D. OLSEN, University of Wisconsin, Madi son, Wis. Anal. Chem. 33, 531 (1961)
J . B. WILLIS, C.S.I.R.O. Chemical Research Laboratories, Melbourne, Australia Anal. Chem. 33, 556 ( 1961) VOL. 33, NO. 4, APRIL 1961
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BRIEFS Extension of the Porter-Silber Reaction to 17Deoxy-alpha-ketolic Steroids A spectrophotometric method is used for the determina tion of micro amounts of pure 17-deoxy-alpha-ketolic steroids. T h e steroids are oxidized t o glyoxals with cupric acetate then treated with Porter-Silber reagent. T h e method is applied to 17-OH-ketols which are converted to glyoxals on paper chromatograms.
Determination of Mixtures of 1,1 -Dimethylhydrazine
Determination
of
Total
Serum
A simple, accurate, and reproducible turbidimetric proce dure is used for determining serum cholesterol. Blood serum samples are diluted with saline and treated with sodium ethylate. The produced turbidity is measured against a standard and the cholesterol concentration cal culated. G. R. KINGSLEY and OZIE ROBNETT, University of California, Los Angeles, Calif. Anal. Chem. 33, 561 (1961)
Paper Chromatographic Separation and Complexometric Titration of Trace Amounts of Strontium and Calcium in Biological M a t e r i a l The calcium and strontium contents of biological materials are simultaneously determined by a complexometric titra tion procedure. T h e elements are separated by paper chromatography, calcinated, and titrated with E D T A . Amounts as little as 1 microgram of calcium and 2 micro grams of strontium are measured. P. A . DUMONT, University of Louvain, Louvain, Belgium
and
A nonaqueous titrimetric procedure is developed for deter mining mixtures of hydrazine and 1,1-dimethylhydrazine. The samples are dissolved in acetic acid and titrated with perchloric acid in dioxane. Specificity is enhanced by us ing salicylaldehyde. H. E. MALONE, Edwards Air Force Base, Calif.
M. L. LEWBART and V. R. MATTOX, Mayo Clinic and Mayo Foundation, Rochester, Minn. Anal. Chem. 33, 559 (1961)
Turbidimetric Cholesterol
Hydrazine
Anal. Chem. 33, 575 (1961)
Determination of Copolymer Composition by In f r a r e d Analysis. Poly (vinyl Acetate )-Poly(methyl A c r y l a t e ) Poly (methyl acrylate)-poly (vinyl acetate) mixtures or co polymers are analyzed for composition by an infrared ab sorptiometry technique. The key factor in composition determination is the ester linkage in the 8.0 and 8.55 mi cron region. S. N. C H I N A I and R. H. CAMPBELL, Monsanto Chemical Co., Boston, Mass. Anal. Chem. 33, 577 (1961)
Spectrophotometric Iron
Determination
of
Ferric
The conditions for a quantitative method for determining ferric iron are investigated. In the presence of ferric iron, dimethyl-p-phenylenediamine is oxidized to give a red pink solution. T h e color intensity is proportional to the ferric iron concentration and is measured at 515 ηιμ. G I O V A N N I CERIOTTI and LUIGI Tumori di Busto, Arsizio, Italy
SPANDRIO, Centro Studio Anal. Chem. 33, 579 (1961)
Anal. Chem. 33, 565 (1961)
Differential Thermal Studies with Simultaneous Gas Evolution Profiles A continuous gas detection system enhances the differen tial thermal investigation of propellants. A gas evolution profile allows the monitoring of the gas evolution from thermal reactions during chemical or physical change of the sample. The technique indicates wider application as a research tool. W . M. AYRES and E. M. BENS, U.S. Naval Ordance Test Station, China Lake, Calif. Anal. Chem. 33, 568 (1961)
Use of Hydrazine to Accelerate the Rate of Hy drogen Sulfide Evolution from Thioacetamide Solutions The reaction between thioacetamide and hydrazine which produces hydrogen sulfide is elucidated and its analytical application indicated. In acid solution the reaction cata lyzes the rapid precipitation of metal sulfides. D. M. KING and F. C. A N S O N , California Institute of Technology, Pasadena, Calif. Anal. Chem. 33, 572 (1961)
Catalysts for Cerium ( I V ) Oxidimetry. Deter mination of Polyhydric Alcohols and Metal Che lates of 8-Quinolinol The oxidation of glycerol, erythritol, pentaerythritol, and 8-quinolinol by cerium (IV) sulfate in perchloric acid is enhanced by a silver(I)-manganese( II) catalyst. Reaction time is between 3 and 5 minutes at 90° C , with the end point indicated by a red color formation. G. G. GUILBAULT, Princeton University, Princeton, N. J . W . H. McCURDY, Jr., University of Delaware, Newark, Del. Anal. Chem. 33, 580 (1961)
Determination of Oxide Film Thickness by Proton Activation Proton activation of naturally occurring oxygen-18 accord ing to the reaction O18 (p, n) F 1 s has been successfully ap plied to the measurement of oxide film thickness on tanta lum. Copper, nickel, and zinc interfere; titanium inter ference is overcome by using proton energy below 3.8 ni.e.v. B. A. THOMPSON, General Electric Co., Schenectady, Ν. Υ. Anal. Chem. 33, 583 (1961) VOL. 33, NO. 4, APRIL 1961
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BRIEFS Quantitative Determination of Metallic Iron in the Presence of Iron Oxides in Treated Ores and Slags Iron in the presence of iron oxides is determined by using copper as a displacement element. The sample is reacted with copper sulfate using a mercury catalyst and the prod uct is dissolved in nitric acid. The copper equivalent is measured electrolytically from which the iron concentra tion is calculated.
The Radiochemical Determination methium-147 in Fission Products
of
Pro-
A radiochemical procedure is devised for the separation and determination of promethium-147 in fission product solutions. Promethium-147 is extracted with a di(2-ethylhexyD-orthophosphoric acid-llltrasene mixture. Activity is measured by liquid scintillation counting. R. D. BRITT, Jr., E. I. du Pont de Nemours & C o . , A i k e n , S. C . A n a l . C h e m . 3 3 , 602 ( 1 9 6 1 )
Μ . Θ . H A B A S H Y , A l e x a n d r i a , E g y p t , U . A . R. A n a l . C h e m . 33, 586 ( 1 9 6 1 )
Sampling Errors in the X-Ray Fluorescent Deter mination of Titanium in a High Temperature Alloy Sampling procedure is of significance in the determination of titanium in high temperature alloys. Agreement be tween x-ray fluorescence and wet chemical procedures was obtained only when the same surface was analyzed by both methods. Special sampling is required since titanium segregation is independent of ingot size. R. F. STOOPS a n d Κ. Η . M c K E E , G e n e r a l E l e c t r i c C o . , D e t r o i t , Mich. A n a l . C h e m . 33, 589 ( 1 9 6 1 )
Spectrophotometric Determination of Ammonia as Indophenol A rapid and sensitive photometric procedure is developed for determining ammonia from Kjeldahl digestions and other solutions. The ammonia is reacted with phenol and hypochlorite to form indophenol which gives a blue color in alkaline solution. The optimum concentration range is 0.3 to 3.0 p.p.m. of ammonia in the color solution. W . T. BOLLETER, C . J . B U S H M A N , a n d P. W . T I D W E L L , santo C h e m i c a l C o . , Texas C i t y , Tex.
Mon
X-Ray Fluorescence Analysis Using Ion Exchange Resin for Sample Support. Determination of Strontium in 0.1 M Calcium Acetate Solutions X-ray fluorescence analysis is used in conjunction with ion exchange for the determination of elemental ions. The solution is passed through an ion exchange column and the resin pressed into a pellet. The fluorescence intensity of the pellet is measured in an x-ray spectrograph. Varia tions are controlled by use of an internal standard. R. L. C O L L I N , C a n c e r Research Institute, N e w England Deaconness H o s p i t a l , Boston, Mass. A n a l . C h e m . 33, 605 ( 1 9 6 1 )
Spectrochemical Determination of Trace Ele ments in Inorganic Salts Using a ConcentrationPrecipitation Technique A concentration-precipitation technique is used to deter mine trace amounts of seven elements in certain inorganic salts. The elements are concentrated by the précipitants, oxine and thionalide, and are simultaneously determined by a direct current arc spectrographic procedure. R. L. D E H M , W . G . D U N N , and E. R. LODER, Eastman Kodak C o . , Rochester 4 , Ν . Υ . A n a l . C h e m . 33, 607 ( 1 9 6 1 )
A n a l . C h e m . 33, 592 ( 1 9 6 1 )
The Jet Fumigator The Theoretical Sensitivity and Linearity Photoelectric Systems for Polarimetry
of
The sources and magnitude of error in photoelectric sys tems for polarimetry' are investigated. Consideration is given to sensitivity of single beam systems and the devialion of the output of these systems from linearity with respect to optical rotation. A . L. R U O Y a n d B E N J A M I N C A R R O L L , Rutgers, The S t a t e U n i v e r s i t y , Newark, N . J . A n a l . C h e m . 33, 594 ( 1 9 6 1 )
Complexometric Determination of Calcium and Magnesium in Ferromanganese Slags A rapid complexometric method is used for determining calcium and magnesium in ferromanganese slags. Inter fering elements are marked with triethanolamine. Cal cium and magnesium are titrated with E D T A in alkaline medium using specific indicators. Α. θ . C . MORRIS, Africa
Ferralloys,
Ltd., Cato
Ridge,
Natal,
South
A n a l . C h e m . 33, 599 ( 1 9 6 1 )
Circle No. 164 on Readers' Service Card
A jet fumigator is developed for generating small amounts of gas for fumigation chamber atmospheres. The device operates continuously and is not limited to gaseous fumigants. Solutions producing liquid or solid aerosols are effectively incorporated. G . L. R O U N D S , J . H . H O E F F E R L E , E. F. G A R N E R , a n d H . J . M A T O I , Kaiser Steel C o r p . , Fontana, C a l i f . A n a l . C h e m . 33, 609 (1961)
Liquid Scintillation Counting of Carbon-14. Use of Ethanolamine-Ethylene Glycol Monomethyl Ether-Toluene A liquid-scintillation counting procedure for carbon-14 is based on the oxidization of organic compounds to carbon dioxide. The gas is trapped in an ethanolamine solution of ethylene glycol monoethyl ether. An aliquot is added to toluene containing a scintillator and counted in a liquid scintillation spectrometer. H E N R Y J E F F A Y a n d J U L I A N A L V A R E Z , U n i v e r s i t y of I l l i n o i s , College of Medicine, Chicago, III. A n a l . C h e m . 33, 612 ( 1 9 6 1 )
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BRIEFS Determination of the Absolute Disintegration Rates of Low Energy Beta Emitters in a Liquid Scintillation Spectrometer The absolute disintegration rate of low energy beta-emit ter ions is determined by an integral counting method us ing a liquid scintillation spectrometer. The results are compared with those calculated from theory and statistical probabilities. Low levels of tritium in water are deter mined. D. L. H O R R O C K S and M . H . STUDIER, Argonne N a t i o n a l Labora tory, Argonne, I I I . A n a l . C h e m . 33, 615 ( 1 9 6 1 )
Determination of Formaldehyde in Gas Mixtures by the Chromotropic Acid Method The West and Sen chromotropic acid method for deter mining formaldeh3'de in gas mixtures is investigated and minor modifications suggested. Interference due to ole fins and aromatic hydrocarbons is eliminated by corrected sampling procedure. N o interference is encountered from nitrogen dioxide, aldehydes, and ketones. A . P. A L T S H U L L E R , D. L MILLER, and S. F. SLEVA, U. S. De partment of H e a l t h , Education, and W e l f a r e , Cincinnati 26, Ohio
Spot Test Microdetermination of DDT and Its Related Compounds in Biological Materials A single spot test is used for the isolation and identification of trace amounts of D D T and its metabolized products in biological specimens. D D T and related compounds are extracted with alcohol and nitrated; in reaction with po tassium hydrazide a characteristic series of colors is pro duced. A R O K I A S A M Y I R U D A Y A S A M Y and A . R. N A T A R A J A N , Forensic Sciences Laboratory, Madras 3, India
State
A n a l . C h e m . 33, 630 ( 1 9 6 1 )
An Absolute Method of Turbidimetric Analysis A method is outlined which, under certain conditions of particle size and size distribution, eliminates empirical comparison and yields an absolute measurement of con centration. The principle of turbidimetric measurement is applied in studies of a silver bromide solution. E. J . M E E H A N and W . H . BEATTIE, University of Minnesota, Minneapolis 14, M i n n . A n a l . C h e m . 33, 632 (1961)
A n a l . C h e m . 33, 621 ( 1 9 6 1 )
Colorimetric Assay for Diosgenin and Related Compounds Crude diosgenin is analyzed for diosgenin content by a rapid colorimetric procedure. Diosgenin when reacted with perchloric acid produces a yellow chromogen having an absorption maximum at 410 ταμ. The procedure is compared with a chromatographic method of anah'sis. S. C . S L A C K and W . J . M A D E R , C i b a Pharmaceutical Products, Inc., Summit, N . J . A n a l . C h e m . 33, 625 ( 1 9 6 1 )
Microdetermination of Formaldehyde in A i r A sensitive spectrophotometric procedure determines low concentrations of formaldehyde in air. The formaldelyde is collected in acidified water and the color developed with Schiff's reagent and acetone. Maximum absorbance is measured at 560 πιμ. Diurnal variations are observed, in dicating high concentration in the morning and late after noon. A . C . R A Y N E R and C . M . J E P H C O T T , O n t a r i o Department of H e a l t h , Toronto, C a n a d a A n a l . C h e m . 33, 6 2 7 ( 1 9 6 1 )
Detection of Olefins by Epoxidation and Hydroxamation and Characterization by Rear rangement of Epoxides to Carbonyl Compounds Olefins are detected by conversion to glycol monoacetates with peracetic acid, and treated with hydroxylamine. The hydroxamic acids are detected as the wine red ferric salt. Another qualitative test is described involving the rear rangement of the epoxides to carbonyl compounds. J . G . S H A R E F K I N and H . E. S H W E R Z , Brooklyn C o l l e g e , Brook lyn, Ν . Υ. A n a l . C h e m . 33, 635 ( 1 9 6 1 )
Detection and Characterization of Acetylenes by Hydration to Carbonyl Compounds and For mation of 2,4-Dinitrophenylhydrazones A qualitative method is used for detecting acetylene in the presence of olefinic functional groups. Acetylene is hydrated t o a carbonyl group which is detected by reac tion with 2,4-dinitrophenylhydrazine. The hydrazone formed produces a red color when reacted with methanolic potassium hydroxide. J. G . SHAREFKIN Brooklyn, Ν . Υ .
and E. M . B O G H O S I A N ,
Brooklyn C o l l e g e .
A n a l . C h e m . 33, 6 4 0 ( 1 9 6 1 )
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