AC BRIEFS Some Applications of the Nitrous O x i d e Acetylene Flame in Chemical Analysis by Atomic Absorption Spectrometry A nitrous oxide—acetylene flame has been applied to the determination of Sr and Ba in rocks, V in fuel oil, Al, Si, and Ti in bauxite, and Ti in steel. Optimizing factors, ionization problems, and interelement interferences are discussed. J. A. B O W M A N and J . B. WILLIS, Division of Chemical Physics, Commonwealth Scientific and Industrial Research Organization, Melbourne, Australia
HIGHLIGHTS TECHNICAL
OF THE
SCIENTIFIC
ARTICLES
IN THIS
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Faradaic Impedance Technique with Twin Cells Two synchronized dropping mercury electrodes are used, one in a cell containing depolarizer with supporting electrolyte and one with supporting electrolyte only ; the two cells may be sequentially compared to obtain the Faradaic series components. The method has been applied to the V'VV* 2 system. DAVID ELLIOTT and G. S. BUCHANAN, School of Chemistry, The University of New South Wales, Kensington, N. S. W., Australia Anal. Chem. 39, 1245 (1967)
Anal. Chem. 39, 1210 (1967)
Photometric Titrations with Dichromatic Light A phototitrator utilizing two wavelengths and photocells connected in opposition makes possible slow and automatic relay titrations as well as accurate complexometric and acid-base titrations with a gradual color change at the end point. ANDERS RINGBOM, BENGT SKRIFVARS, and EBBE STILL, Department of Chemistry, Abo Akademi Abo, Finland Anal. Chem. 39, 1217 (1967)
Microdetermination of Oxygen in Organic Compounds Using Nondispersive Infrared Absorptiometry A method for the determination of between 0.5 and 1.4 mg of oxygen in organic samples analyzes the combustion gas for CO by means of a nondispersive infrared gas analyzer. T h e existence of a hidden error, a time-variable blank, in the Unterzaucher procedure is discussed. J. A. KUCK, A. J. ANDREATCH, and J. P. MOHNS, Microanalytical and Instrumental Groups, Central Research Division, American Cyanamid Co., Stamford, Conn. Anal. Chem. 39, 1249 (1967)
Supporting Electrolyte Effects in Nonaqueous Electrochemistry. Coordinative Relaxation Reactions of Reduced Metal Acetylacetonates in Acetonitrile Reported is a study of the shift of reduction potentials of metal acetylacetonates in acetonitrile by the addition of LiClOi to the tetraethylammonium percnlorat.e supporting electrode. Polarographic data for the interaction of the F e ( I I I ) aeetylacetonate complex with the medium are included. ROYCE W . MURRAY and L. KENNETH HILLER, Jr., Department of Chemistry, University of North Carolina, Chapel H i l l , N. C. 27514
Measurement of Organic Carbon in W a t e r Using the Hydrogen-Flame Ionization Detector A precision of ± 5 % for replicate determinations of a given standard solution is reported for the measurement of organic carbon in water using a combustion—reduction chromatographic unit. T h e efficiency of the reduction and combustion steps has been evaluated. RICHARD A. DOBBS, ROBERT H. WISE, and ROBERT B. DEAN, U. S. Department of Interior, Federal Water Pollution Control Administration, Cincinnati, Ohio 45226 Anal. Chem. 39, 1255 (1967)
Anal. Chem. 39, 1221 (1967)
A Modular, Transistorized ControlledPotential Coulometer The plug-in integrator and potcntiostat modules are designed to operate independently or together as a controlled-potential coulometer. T h e instrument is capable of an output of ± 24 V at ± 400 mA without current polarity switching. Included are a number of analytical determinations to test the performance of the coulometer.
Determination of Sub-PPM Nickel and Vanadium in Petroleum by Ion Exchange Concentration and X-Ray Fluorescence A method for the simultaneous determination of Ni and V at the 0.1-ppm level utilizes decomposition by ashing, concentration on a thin disk of cation exchange paper, and determination by x-ray fluorescence. Xo intcrclemcntal effects between Xi, V, and Fe were observed.
J. E. HARRAR and ERVIN BEHRIN, Lawrence Radiation Laboratory, University of California, Livermore, Calif. 94550
J . G. BERGMANN, C. H. EHRHARDT, L. GRANATELLI, and J. L. JANIK, Research and Development Department, American Oil Co., Whiting, Ind.
Anal. Chem. 39, 1230 (1967)
Anal. Chem. 39, 1258 (1967)
Coulostatic Titrations Using a Dropping Mercury Electrode
Exchange Equilibrium through Anion Exchange Membranes
Coulostatic relaxation curves have been used to measure the end points of titrations of Zn, Cd, Pb, and M n with KDTA. An equation has been derived for the dropping mercury electrode during the relaxation process.
The permselectivity of anion exchange membranes for systems containing divalent anions and the time required to reach ion exchange equilibrium have been compared with corresponding data for cation exchange membranes.
RICHARD W . SORENSEN and R. F. SYMPSON, Department of Chemistry, Ohio University, Athens, Ohio
W . J . BLAEDEL and E. L. CHRISTENSEN, Chemistry Department, University of Wisconsin, Madison, Wis. 53706
Anal. Chem. 39, 1238 (1967)
Anal. Chem. 39, 1262 (1967) VOL. 39, NO. 1 1 , SEPTEMBER 1967
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AC BRIEFS A New Method for Measuring the Oxidation Stability of Elastomers A quartz crystal electronic microbalance has been em ployed to measure changes in polymer mass resulting from surface oxidation. Factors studied include elastomer types, filler types, vulcanization, inhibitors, temperature, and ultraviolet radiation. W . F. FISCHER and W . H. KING, Jr., Esso Research and Engl neering Co., Linden, N. J . Anal. Chem. 39, 1265 (1967)
Direct Determination of Amine Salt-Base Ratios by Nuclear Magnetic Resonance Spectrometry; Correlation of Acid Strengths in Chloroform by Nuclear Magnetic Resonance and Infrared Spectrometry T h e chemical shift of the jV-methyl proton N M R signal is used to determine the proportion of amine salt to free amine in a chloroform extract of the amine from specific acids. Correlations with infrared data are included. STANLEY A . KOCH and THOMAS D. DOYLE, Food and Drug Administration, Division of Pharmaceutical Chemistry, Washington, D. C. 20204 Anal. Chem. 39, 1273 (1967)
Use of M e t a l Ion Catalysis in Detection and Determination of Microamounts of Complexing Agents. Determination of EthylenediamineNNN'N'-Tetraacetic Acid A method for the determination of microgram amounts of ethylenediamine-A r jYA 7 W-tetraacetic acid is based on the periodate oxidation of malachite green catalyzed by M n ( I I ) . T h e protonated E D T A complex of M n ( I I ) , which forms at low p H , has enhanced sensitivity for nitrogen-containing ligands. H O R A C I O A. MOTTOLA and HENRY FREISER, Department of Chemistry, University of Arizona, Tucson, Ariz. Ana!. Chem. 39, 1294 (1967)
Notes Microdetermination of W a t e r in Hydrocarbon Solvents, Using Ultraviolet Spectrophotometry, by Reaction with N-Benzilideneaniline A method for the determination of as little as 0.05 ppm water in hydrocarbon solvents is based on the hydrolysis of .V-benzilidcneaniline by ultraviolet irradiation. IGNAZIO RENATO BELLOBONO, Istituto di chimica fiscia dell' Universita, Milan, Italy Anal. Chem. 39, 1298 (1967)
Fine Structure of Isotopically Labeled Amino Acids Determined by Ion Exchange Chromatography The chromatographic mobilities of tritium-labeled and radiocarbon-labeled forms of 11 amino acids have been compared with unlabeled forms on ion exchange columns. Retention volume has been correlated with isotope posi tion. PETER D. KLEIN and PATRICIA A . SZCZEPANIK, Division of Bio logical and Medical Research, Argonne National Laboratory, Argonne, III. Anal. Chem. 39, 1276 (1967)
Application of Ion-Pair Extraction to Partition Chromatographic Separation of Pharmaceutical Amines T h e choice of stationary phase composition and proper solvent for the elution of the pyrilamine maleate-codeine sulfate system has been investigated. T h e complicating effects of more than one basic site and free base extraction are reported. THOMAS D. DOYLE and JOSEPH LEVINE, Food and Drug A d ministration, Division of Pharmaceutical Chemistry, Washington, D. C. 20204 Anal. Chem. 39, 1282 (1967)
Estimation of Potassium in Mixtures with Lithium and Sodium by Nonaqueous Titration Potassium in mixtures with sodium or lithium is deter mined by potentiometrically titrating the acetate salt in acetic acid-chloroform with perchloric acid in dioxane. ISWORI LAL SHRESTA and MIHIR NATH DAS, Physical Chem istry Laboratories, Jadavpur University, Calcutta-32, India Anal. Chem. 39, 1300 (1967)
Concentration Gradients in Film and Spherical Mercury Electrodes under Variable-Flux Plating Conditions The theory of amalgam formation has been extended to include time-dependent plating conditions with emphasis on the relationship between the flux of the metal ion and t-Ά. SIDNEY L. PHILLIPS and LAWRENCE F. KARR, International Business Machines Corp., Systems Development Division, Box 390, Poughkeepsie, N. Y. I2602 Anal. Chem. 39, 1301 (1967)
Direct Determination of Fluoride in Tungsten Using the Fluoride Ion Activity Electrode After fusion decomposition of the sample under controlled temperature conditions, the p F of fluoride is determined by using a fluoride ion activity electrode with an expanded-scale p H meter. BRUCE A. RABY and W I L L I A M E. SUNDERLAND, Lawrence Radiation Laboratory, University of California, Livermore, Calif.
Computer Search System f o r Retrieval of Infrared Data
Anal. Chem. 39, 1304 (1967)
T h e search system compares spectra at the rate of 10,000 per minute and arranges them in order of probability of match. Included is a detailed analysis of the mandatories and desirables associated with the absorption peak search of resorcinol and p-dichlorokengene.
Scale Expansion and Increase in Sensitivity in Rotational Viscosimetry Instrument modifications have been proposed which in crease the sensitivity and extend the applicability to vis cosity measurements in physiologically important regions.
DON H. ANDERSON and G. L. COVERT, Eastman Kodak Co., Rochester, N. Y. I4650
EBERHARD Z I M M E R M A N N , Physiologisch-Chemisches Institut der Universitat, 87 Wurzburg, W . Germany
Anal. Chem. 39, 1288 (1967)
Anal. Chem. 39, 1305 (1967) VOL. 39, NO. 1 1 , SEPTEMBER 1967
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AC BRIEFS Chelate Formation of Tetravalent Vanadium with Pyrocatechol Violet Reported is a study of the composition and stability of the vanadium(IV)—pyrocatechol violet chelate evaluated b y the continuous variation and mole ratio methods. S. P. M U S H R A N , O M P R A K A S H , and J . N . A W A S T H I , University of A l l a h a b a d , A l l a h a b a d , India A n a l . C h e m . 39, 1307 ( 1 9 6 7 )
Determination of Nitrogen in Transition Metal Nitrides by Tube Furnace Oxidation and Gas Chromatographic Measurement Nitrides of N b , Zr, V, Ti, and Mo have been analyzed b y tube furnace oxidation; nitrogen is determined by gas chromatography using gaseous N 2 for calibration. R. A . MEYER, E. P. PARRY, and J . H . D A V I S , North American Aviation Science Center, Thousand Oaks, C a l i f . 93160 A n a l . C h e m . 39, 1321 ( 1 9 6 7 )
Analysis of Bituminous Coal by a Combined Method of Ozonolysis, Gas Chromatography, and Mass Spectrometry A procedure for the isolation and identification of bitu minous coal degradation products combines the techniques of ozonolysis, gas chromatography, infrared, ultraviolet, and mass spectrometry. T h e coal composition has been compared before and after repeated oxidative degradation. SISTER M . C A R O L BITZ and B A R T H O L O M E W Ν Α Θ Υ , University of C a l i f o r n i a at San Diego (La J o l l a ) , C a l i f . 9 2 0 3 8 A n a l . C h e m . 3 9 , 1310 ( 1 9 6 7 )
Simple Approximation for Pressure Correction Factor in Gas Chromatography Reported is a technique for approximating the pressure gradient correcting factor, ;', for routine gas chromato graphic applications. I S T V Â N H A L Â S Z and E R W I N H E I N E , Institut fur Physilcalische C h e m i e der Universitat, Frankfurt am M a i n , G e r m a n y A n a l . C h e m . 3 9 , 1313 ( 1 9 6 7 )
Gas Chromatographic Determination of Formaldehyde by Sucrose O c t a - A c e t a t e Columpak Τ Formaldehyde has been separated from water and metha nol and determined by elution on sucrose octa-acetate on Columpak T. Sensitivities of gas density and thermal conductivity detectors were compared. R. S. M A N N and K. W . H A H N , Department of Chemical neering, University of O t t a w a , O t t a w a 2, C a n a d a
Retention Time-Boiling Point Correlations During Programmed Temperature Capillary Column Analysis of C 8 - C 1 2 Aromatic Compounds A mixture of C 8 to Cu aromatic hydrocarbons has been resolved by elution on a ditridecylphthalate capillary column. Components having identical boiling points may be identified by reference to the elution curves for each carbon number. D O N A L D E- W I L L I S , Hydrocarbons and Polymers Division, M o n santo C o . , St. Louis, M o . A n a l . C h e m . 39, 1324 ( 1 9 6 7 )
Thin Layer Chromatographic Separation and Spectrophotometric Determination of Benzol! a ] pyrene in Organic Extracts of Airborne Particulates Reported are modified techniques for the determination of benzo[a]pyrene in air particulates by thin layer chro matography-spectrophotometry. Results are compared with other methods. T H O M A S W . STANLEY, M Y R N A J . M O R G A N , and J A M E S E. MEEKER, N a t i o n a l Center f o r A i r Pollution C o n t r o l , Public H e a l t h Service, 4 6 7 6 Columbia Parkway, Cincinnati, Ohio 45226 A n a l . C h e m . 39, 1327 ( 1 9 6 7 )
Engi
A n a l . C h e m . 3 9 , 1314 ( 1 9 6 7 )
Separation and Determination of Trinitrotoluene Isomers by Gas Chromatography Individual T N T and D N T isomers have been separated by gas chromatography. T h e technique makes it possible to monitor 2,4,6-TNT for low concentrations of unsymmetrical isomers. D. Θ . G E H R I N G and J . E. S H I R K , Eastern Laboratory, Explosives Department, E. I. du Pont de Nemours & C o . , Gibbstown, N . J .
Separation of Zirconium(IV) and Thorium ( I V ) from Each Other and from Numerous Metal Ions by Aqueous Paper Chromatography Reported is the separation of T h from metal ions by using 40% H N O j saturated with oxalic acid. Zr has been effec tively separated from other cations by the use of a H C 1 HaPOi-water system. MOHSIN QURESHI and FAHMIDA K H A N , Chemical Labora tories, Aligarh Muslim University, Aligarh, U.P., India Anal. Chem. 39, 1329 (1967)
A n a l . C h e m . 39, 1315 ( 1 9 6 7 )
Quantitative Gas Chromatographic Determination of Ethanolamines as Trifluoroacetyi Derivatives T h e reaction of trifluoroacetic anhydride with the amino groups of mono- and diethanolamine and the hydroxyl groups of mono-, di-, and triethanolamine is the basis of a GC procedure employing thermal conductivity and flame ionization detection.
Determination of Trace Metals in Terephthalic Acid by Ion Exchange Concentration and X-Ray Fluorescence Trace amounts of Ni, Co, Fe, M n , Cr, and Ti in ter ephthalic acid have been determined by collection on cat ion and anion exchange disks and x-ray fluorescence counting.
L. E. B R Y D I A and H . E. P E R S I N G E R , Union C a r b i d e C o r p . , C h e m icals and Plastics, South Charleston, W - V a .
J . G . B E R G M A N N , C . H . E H R H A R D T , L. G R A N T A E L L I , and J . L. J A N I K , Research and Development Department, A m e r i c a n O i l C o . , W h i t i n g , Ind.
A n a l . C h e m . 39, 1318 ( 1 9 6 7 )
A n a l . C h e m . 39, 1331 ( 1 9 6 7 )
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AC BRIEFS Radiochemical Separation of Copper by Amalgam Exchange The radiochemical separation technique is based on isotopic exchange between deposited copper in the mercury phase and radioactive cupric ions in dilute acid. T a b ulated are data for the separation of copper from vari ous contaminants.
The Straight Line to Atomic Absorption and Flame Emission Efficiency
R. R. RUCH and J . R. DEVOE, Activation Analysis Section, Ana lytical Chemistry Division, National Bureau of Standards, Wash ington, D. C. 20234 Anal. Chem. 39, 1333 (1967)
Trace Element Determination by Electrochromatographic Radiometric Precipitation Ba and Sr ions and rare earth elements precipitate with la beled anions of H2SO.1 and diammonium phosphate, and the excess precipitant migrates toward the anode. T h e element is located by radioautograph and counted by liquid scintillation techniques.
PRE-MIX BURNERS
ROBERT S. MORSE, GEORGE A . WELFORD, and ELIAS L. CHIOTIS, Health and Safety Laboratory, United States Atomic Energy Commission, New York, Ν. Υ. Anal. Chem. 39, 1336 (1967) THE TECHTRON PRE-MIX BURNER-NEBULIZER SYSTEM gives you greater versatility and efficiency in both atomic absorption and flame emission than any other system available.
Correspondence Reactions of Labile Trimethylsilyl Derivatives with Fluorocarbons in a Gas C h r o m a t o g r a p h Mass Spectrometer System R. L. FOLTZ, M. B. NEHER, and E. R. HINNENKAMP, Organic Chemistry Division, Battelle Memorial Institute, Columbus, Ohio 43201 Anal. Chem. 39, 1338 (1967)
Aids for Analytical Chemists
• It is designed integrally, and will fit almost all current AA spectrophotometers. Flame noise is low,- performance is high. Rapid burner interchangeability permits use of the most efficient fuel and support gas mixtures. Standard or variable nebulizers may be specified. AA burners available: AB-40 Nitrous Oxide/Acetylene; AB-41 Air/ Acetylene; A8-42 Air/Propane, Air/Coal Gas; AB-43 Air/Hydrogen; AB-44 Air/Acetylene (three-slot Boling type). • Techtron Flame Emission Burners permit a quick switch from AA to FE — with the use of a simple chopper assembly. FE Burn ers for Air/Acetylene and Nitrous Oxide/ Acetylene are in the Techtron line.
Modification of a Gas Chromatograph f o r Subambient Temperature Control W I L L I A M DAMMEYER, Research Council of Alberta, Edmonton, Alberta, Canada Anal. Chem. 39, 1339 (1967)
Determination of Methyl-Ethyl Lead Alkyls and Halide Scavengers in Gasoline by Gas Chromatography and Flame Ionization Detection NESTOR L. SOULAGES, Laboratorio Petrotecnico, Yacimientos Petroliferos Fiscales, Florencio Yarela, Republica Argentina Anal. Chem. 39, 1340 (1967)
A Sealed Thin Window X-Ray Tube for Light and Heavy Element Excitation T. D. KIRKENDALL and P. F. VARADI, The Machlett Laboratories, Inc., Division of Raytheon Co., Stamford, Conn. Anal. Chem. 39, 1342 (1967)
Standard and High Intensity Lamps • Over 65 elements in single element lamps, multi-element lamps, and high intensity* lamps (more than 20 elements) give the analyst in AA the widest and most selective source of lamp supply in the world. Also available from Canadian Research Institute, Don Mills, Ontario. *As developed by C.S.I.R.O.
See all the latest in AA spectrophotometry developments — Booth 17 — NIH Exhibit.
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