AC BRIEFS Highlights of the scientific and technical articles in this issue Nuclear Magnetic Resonance Studies of Protonation of Polyamine and Aminocarboxylate Compounds in Aqueous Solution Substituent shielding constants obtained from a study of methylenic proton chemical shifts of model compounds as a function of p H are employed to determine the dis tribution of protons among various sites on the ligand. JAMES L. SUDMEIER and CHARLES N. REILLEY, Department of Chemistry, University of North Carolina, Chapel H i l l , N. C.
Characterization of Selected Heavy-Metal Salts as Adsorbents for Gas Chromatography Studies with a number of salts indicated that separations are greatly influenced by interaction between the metal ion of the adsorbent and the 7r-electrons or nonbonded electrons of the adsorbate. A L A N Θ. ALTENAU and L. B. ROGERS, Department of Chemis try, Purdue University, Lafayette, [nd. Anal. Chem. 36, 1726 (1964)
Anal. Chem. 36, 1698 (1964)
Nuclear Magnetic Resonance Studies of Protonation of Some Polyaminocarboxylate Compounds Containing Asymmetric Carbon Atoms Proton magnetic resonance spectra of Zraiis-(l,2-cyclohexylenedinitrilo)tetraacetic acid, ircms-l,2-diaminocyclohexane, di-(l,2-propylenedmitrilo)tetraacetic acid, and meso-(2,3-butylenedinitrilo)tetraacetic acid at various p H s were studied.
Piezoelectric Sorption Detector This work indicates several advantages possessed by gas chromatographic detectors produced from crystals coated with gas chromatographic substrates. W I L L I A M H . KING, Jr., Analytical Research Division, Esso Re search and Engineering Co., Linden, N. J . Anal. Chem. 36, 1735 (1964)
JAMES L. SUDMEIER and CHARLES N. REILLEY, Department of Chemistry, University of North Carolina, Chapel H i l l , N. C. Anal. Chem. 36, 1707 (1964)
Quantitative Determination of Hydrogen and Fluorine in Organic Compounds by Nuclear Magnetic Resonance Spectrometry The method involves the use of reference standards and area ratio measurement at experimentally determined power levels and scan rates. I t has been used for elemen tal analysis and compound and functional group deter mination.
Electron Drift-Velocity Detector for Gas Chromatography The effect of trace impurities on the drift-velocity of elec trons in pure argon has been exploited for the detection of trace concentrations of permanent gases in gas chroma tography. V. N. SMITH and J . F. FIDIAM, Shell Development Co., Emery ville, Calif. Anal. Chem. 36, 1739 (1964)
PAUL J . PAULSEN and W . D. COOKE, Department of Chemistry, Cornell University, Ithaca, Ν. Υ. Anal. Chem. 36, 1713 (1964)
Determination of Active Hydrogen by Nuclear Magnetic Resonance Spectrometry The proposed method is based on the exchange reaction of the group with heavy water and the determination of the exchanging protons by N M R spectrometry. I t is non destructive, more precise than conventional methods, and can be applied to less reactive groups such as acetylcnic hydrogen and CH 3 CO— groups. PAUL J . PAULSEN and W . D. COOKE, Baker Laboratory, Cornell University, Ithaca, Ν. Υ. Anal. Chem. 36, 1721 (1964)
Chronopotentiometry and Chronoamperometry with Unshielded Planar Electrodes It is shown that the nonlinearity of the diffusion field about unshielded planar electrodes can be corrected for by extrapolating the experimental values of the chronopotentiometric and chronoamperometrie constants t o the τ χ / 2 = 0 or the t1/» = 0 concept. PETER JAMES LINGANE, Department of Chemistry and Chemi cal Engineering, California Institute of Technology, Pasadena,
Calif. Anal. Chem. 36, 1723 (1964)
Carbon Skeleton Chromatography Using H o t - W i r e Thermal-Conductivity Detection The apparatus described produces enough product for spectral analysis, from which identifications made on the basis of retention time may be confirmed or denied. Peaks are usually sharp and well resolved. MORTON BEROZA and RAFAEL SARMIENTO, Entomology Re search Division, Agricultural Research Service, U. S. Department of Agriculture, Beltsville, M d . Anal. Chem. 36, 1744 (1964)
Study of Solid Support and Partition Liquid Interactions in Gas Chromatographic Separation of Ethanol-Methanol Mixtures Superior columns for this separation were readily achieved, with either alcohol being selectively retained through the proper choice of the solid support and parti tion liquid. EDGAR D. SMITH, JUNIOR L. J O H N S O N , and J . M. OATHOUT, University of Arkansas, Institute of Technology, Little Rock, Ark. Anal. Chem. 36, 1750 (1964) VOL. 36, NO. 9, AUGUST 1964
•
9 A
BRIEFS Studies of the Liquid Phase Mass-Transfer Term in Gas Chromatography T h e functional dependence of the liquid phase mass-trans fer term in gas chromatography has been studied as a func tion of liquid loading with helium, nitrogen, and argon as carrier gases. JAMES K. BARR and DONALD T. SAWYER, Department of Chemistry, University of California, Riverside, Calif. 92502 Anal. Chem. 36, 1753 (1964)
A Study of the Cerium ( I V ) - O x a l a t e Reaction in Acidic Sulfate Media Spectrophotometric evidence supports a mechanism in volving, prior to the rate determining oxidation-reduction step, the formation of a transient intermediate complex with properties which explain the observed variation in reaction rate with the nature and concentration of solvent anions. Y. A . EL-TANTAWY and Θ. A. RECHNITZ, Department of Chem istry, University of Pennsylvania, Philadelphia, Pa. Anal. Chem. 36, 1774 (1964)
Determination of Residual Monomers in Latex by Gas Chromatography The limits of monomer detection vary from 100 p.p.m. by weight for vinyl chloride to 500 p.p.m. by weight for «-butyl acrylate. Relative standard deviation is no greater than 10%. L. BETH WILKINSON, CHARLIE W . N O R M A N , and J O H N P. BUETTNER, Central Laboratory, Texas Division, The Dow Chemical Co., Freeport, Texas Anal. Chem. 36, 1759 (1964)
Separation, Identification, and Spectra of the Anionic Chromium(III)—Thiocyanate Complexes The cellulose anion exchanger, Seleclacel D E A E (diethylaminoethyl cellulose) has been used to separate the complexes. The low affinity of this exchanger for these ions allows their elution under mild conditions. SHELDON KAUFMAN and LEWIS S. KEYES, Department of Chemistry, Princeton University, Princeton, N. J . Anal. Chem. 36, 1777 (1964)
Formation Constants of N i c k e l ( l l ) and Z i n c ( l l ) Complexes of Dithizone and Related Compounds The formation constants were determined spectrophotometrically in 50 volume % aqueous dioxane. T h e results suggest that whereas the Zn complexes of dithizone and the substituted derivatives involve N - and S-metal bonds, the Ni complexes involve only N-metal bonds. K. S. MATH, OUINTUS FERNANDO, and HENRY FREISER, De partment of Chemistry, University of Arizona, Tucson, Ariz. Anal. Chem. 36, 1762 (1964)
An Investigation of the Dissociation Phenomena of Quinoline-8-Selenol in W a t e r and Aqueous Dioxane The acid dissociation constants of selenoxine, its Se-methyl derivative, and the S-methyl derivative of quinoline-8thiol (thiooxine) were determined and were used t o eluci date the dissociation phenomena of oxine, thiooxine, and selenoxine in aqueous media. EIICHI SEKIDO, OUINTUS FERNANDO, and HENRY FREISER, Department of Chemistry, University of Arizona, Tucson, Ariz. Anal. Chem. 36, 1768 (1964)
Ion Exchange Separation of Microgram Quantities of Osmium from Large Amounts of Base Metals Losses of osmium in the effluent which result from evap oration of HC1 solutions of hexachloroosmates may be controlled by a prior treatment of the osmium solution with sulfur dioxide. J. C. V A N LOON and F. E. BEAMISH, Department of Chemistry, University of Toronto, Toronto 5, Ontario, Canada Anal. Chem. 36, 1771 (1964)
Determination of Hydrogen in Niobium The analysis is based upon evolving the hydrogen at elevated températures, converting to water, and weighing the water. I t is useful down to H contents of 22/A p.p.m., where A is the sample weight in grams, and for higher H concentrations in large samples. R. J . WALTER and H. G. OFFNER, Research Department, Rocketdyne, A Division of North American Aviation, Inc., Canoga Park, Calif. Anal. Chem. 36, 1779 (1964)
Cold Combustion for the Quantitative Determination of Amalgable Metals in the Presence of Their Oxides in Treated Ores The sample is mixed with mercury and water, and the mixture is then shaken in a known volume of oxygen. The volume of gas consumed by the amalgamated metal can be directly measured at atmospheric pressure with the "cold combustimeter." M. G. HABASHY, Special Laboratory, 25 Sultan Hussein St., Alexandria, Egypt, U.A.R. Anal. Chem. 36, 1781 (1964)
Determination of Traces of Alkaline Earths in Alkali Halides by Spectrophotometric Titration in the Ultraviolet The titration, carried out using the large absorbance of the alkali E D T A complex, will determine any of the alkaline earth ions or their sum if a mixture is present. E. P. PARRY and G . W . DOLLMAN, North American Aviation Center, A Division of North American Aviation, Inc., Canoga Park, Calif. Anal. Chem. 36, 1783 (1964) VOL. 36, NO. 9, AUGUST 1964
•
11
A
BRIEFS Formation of Lead Chloride Fluoride a t Lower pH Values for Gravimetric Purposes Conditions given permitted good gravimetric and volu metric recoveries of fluoride and satisfactory values of the P b : C l ratio when the p H was maintained at 1.8 to 2.0. R A Y M O N D A . B O U R N I Q U E and L I O N E L H . D A H M E R , Chemis try Department, M a r q u e t t e University, 1217 W . Wisconsin A v e . , Milwaukee, W i s . 53233 A n a l . C h e m . 36, 1786 ( 1 9 6 4 )
Ultraviolet Spectrometric Determination of Mixtures of Arylsulfonie Acids The absorbances of the unknown mixture and of its con stituents, in water or aqueous H 2 S0 4 , measured at a large number of wavelengths, are subjected to a least squares treatment by an electronic computer. J . M . A R E N D S , H A N S C E R F O N T A I N , I. S. H E R S C H B E R G , A . J . P R I N S E N , and A . C . M . W A N D E R S , Laboratory for O r g a n i c Chemistry, University of Amsterdam, The Netherlands A n a l . C h e m . 3 6 , 1802 ( 1 9 6 4 )
Rapid Chemical Analysis of Refractory Chrome Ores and Chrome-Bearing Refractories For the spectrophotometric determination of silica, iron, alumina, and chromium, the sample is fused with a sodium carbonate-sodium borate mixture in a platinum crucible. A separate sample is fused with sodium peroxide for the determination of Ca by flame photometry and Mg by titrimetry. C A L V I N S. R I C H A R D S and EVERETT C . B O Y M A N , Kaiser Re fractories Research Department, M i l p i t a s , C a l i f . A n a l . C h e m . 36, 1790 ( 1 9 6 4 )
Separation of Lead by Anion Exchange Using Dowex 1, X 8 , lead is adsorbed from a mixture of 90% tetrahydrofuran and 10% 5Λ" nitric acid. Lead is subsequently eluted with a mixture of 80% tetrahydro furan and 20% 2.5N nitric acid. J O H A N N K O R K I S C H and F R A N Z FEIK, A n a l y t i c a l Institute, University of Vienna, Wahringerstrasse 38, Vienna, Austria A n a l . C h e m . 3 6 , 1793 ( 1 9 6 4 )
Solvent Extraction of Platinum and Palladium with Derivatives of Dithiocarbamic Acid The dibenzyl derivative was found to be the most promis ing chelating agent. I t was made t h e basis of a scheme for the simultaneous separation of P t and P d from certain other metals, using chloroform as the extractant. J O H N T. PYLE and W I L L I A M D. J A C O B S , Department of C h e m istry, University of G e o r g i a , Athens, G a . A n a l . C h e m . 3 6 , 1796 ( 1 9 6 4 )
Indirect Spectrophotometric Determination of Ammonia In the method ISirla is oxidized to nitrogen by hypobromite, and the differential absorbance at 330 ταμ of the sample relative to that of a reference standard is propor tional to the NH3 concentration. J . H . H o w e l l and D. F. BOLTZ, Department W a y n e State University, Detroit, M i c h .
of
Chemistry,
A n a l . C h e m . 3 6 , 1799 ( 1 9 6 4 )
A Reversible Internal Indicator for Sodium Nitrite Titrations Dic3'anobis(l,10-phenanthroline)iron(II) (ferrocyphen) is shown to be a reliable indicator for titrating sulfamates and azides, as well as certain aromatic amine derivatives, with sodium nitrite. A L F R E D A . S C H I L T and JERRY W . S U T H E R L A N D , Department of Chemistry, Northern Illinois University, DeKalb, I I I . A n a l . C h e m . 36, 1805 ( 1 9 6 4 )
Tabulation f o r Deriving Procedural Rate Constants from Dynamic Thermograms In the scheme presented, the numerous measurements, derivations, calculations, and appropriate corrections nec essary t o derive the standard graphical expression for log k vs. XIΤ are broken down into a step-by-step outline form. J . A . M A G N U S O N , Silicone Products Department, G e n e r a l Elec tric C o . , W a t e r f o r d , Ν . Υ . A n a l . C h e m . 36, 1807 ( 1 9 6 4 )
Determination of Acetic Acid in Blood and Other Tissues by Vacuum Distillation and Gas Liquid Chromatography Acetic acid is separated from a copper sulfate saturated perchloric acid filtrate of blood or other tissue by incom plete vacuum distillation, and details for its estimation in the distillate by gas liquid chromatography are given. D A V I D LESTER, Center of Alcohol Studies, Rutgers—The State University, New Brunswick, N . J . A n a l . C h e m . 36, 1810 ( 1 9 6 4 )
Reduction of Aromatic Disulfides with Triphenylphosphine The reduction to thiols is carried out in aqueous methanol. I t is rapid, quantitative, and occurs at room temperature. R A Y E. H U M P H R E Y and JERRY M . H A W K I N S , Department of Chemistry, Sam Houston State C o l l e g e , Huntsville Texas A n a l . C h e m . 3 6 , 1812 ( 1 9 6 4 )
VOL. 36, NO. 9, AUGUST 1964
•
13 A
BRIEFS Determination of Microgram Quantities of Chloride in High Purity Titanium by X-Ray Spectrochemical Analysis In the method described, the chloride is precipitated as AgCl from a H F and H N O a solution of the Ti metal. After filtering the AgCl onto a Millipore filter pad, the silver K-alpha spectra measures the chloride. J . S. R U D O L P H and R. J . N A D A L I N , Westinghouse Research Laboratories, Beulah Road, Churchill Boro, Pittsburgh 35, Pa. A n a l . C h e m . 36, 1815 ( 1 9 6 4 )
Approximate Degrees of Polymerization of Cellulose Esters from Intrinsic Viscosities Equations and graphs are presented using cellulose vis cosities in cupriethylenediamine and cuprammonium solu tion and cellulose ester viscosities in acetone, methylene chloride-alcohol, acetic acid, and pyridine. LEO B. G E N U N G , Cellulose Technology Division, Eastman Kodak C o . , Rochester, Ν . Υ . A n a l . C h e m . 36, 1817 ( 1 9 6 4 )
Determination of Carbon in Sodium by Isotope Dilution Mass Spectrometry Details are described for the determination of elemental carbon using Van Slyke oxidation. Accuracy and precision in the ranges 50 ± 10 μ%. t o 150 ± 25 /*g. of carbon have been demonstrated. KEN Υ. ΕΝΘ, RAYMOND A. MEYER, and CARLETON D. B I N G H A M , Atomics International, A Division of North American Aviation, Inc., Box 309, Canoga Park, Calif. Anal. Chem. 36, 1832 (1964)
Spectrophotometry Determination of p-Chloroacetanilide in Phenacetin-Acid Hydrolysis Method As little as 10 p.p.m. p-chloroacetanilide can be deter mined in the procedure, which includes refiuxing with 48% HBr, making the mixture alkaline, and extracting the pchloroaniline formed with cyclohexane followed by its determination by ultraviolet spectrophotometry. W . B. CRUMMETT, J . SIMEK, and V. A . STENGER, Special Serv ices Laboratory, The Dow Chemical Co., Midland, Mich. Anal. Chem. 36, 1834 (1964)
Spectrophotometric Determination of Trace Fluoride in Organic Compounds Following Combustion in Oxyhydrogen Flame-Quartz Combustion Tube After burning, the sample is passed over quartz packing at 1000° C , and the decomposition products are absorbed in boric acid solution. The dissolved fluoride is deter mined spectrophotometrically by measuring its bleaching action on the Zirconium-SPADNS complex. D. E. W I L L I S and W . T. C A V E , C e n t r a l Research Department, Monsanto C o . , St. Louis, M o . A n a l . C h e m . 3 6 , 1821 ( 1 9 6 4 )
With an aqueous solution of sample in the hydrogen ion form, the ammonium ions are retained by the resin, b u t acetamide is not retained and is determined in t h e eluate by a semimicro Kjeldahl distillation and titration with HC1. PERRY KING and JOSEPH R. SIMMLER, Mallinckrodt Chemical Works, St. Louis 47, Mo. Anal. Chem. 36, 1837 (1964)
Determination of Fluorine in Fluorine-Oxygen Mixtures
A Rapid Method for the Determination of Micro Amounts of Sulfur in Selenium The method, which is based on the purple-colored sulfurpararosaniline compound, incorporates numerous modifi cations in the preparation of colorimetric reagents and the technique of color development. L A S Z L O A C S and S I L V I O BARABAS, C a n a d a n C o p p e r Limited, M o n t r e a l East, Q u e b e c , C a n a d a
Ion Exchange Separation of Acetamide from Ammonium Acetate and Its Determination
Refiners
A n a l . C h e m . 3 6 , 1825 ( 1 9 6 4 )
Analysis of Bound Styrene-Butadiene Content of Copolymers by Infrared Absorbance Ratio Method The composition ratio is a linear function of the ratio of the 1639 cm. - 1 vinyl and the 1601 cm. - 1 phenyl absorption bands measured from suitable base lines. Standard de viations of 0.2% are obtained. A R T H U R S. W E X L E R , Dewey and A l m y Chemical Division, W . R. G r a c e and C o . , C a m b r i d g e 4 0 , Mass. A n a l . C h e m . 3 6 , 1829 ( 1 9 6 4 )
A liquid sample is vaporized completely and allowed to expand into a Teflon-coated cell with sapphire windows. The per cent absorption is read directly from the recorder of a spectrophotometer and converted to volume or weight concentration from calibration curves. SAMUEL KAYE and J . E. KOENCY, General Dynamics/Astro nautics, San Diego 12, Calif. Anal. Chem. 36, 1838 (1964)
Factors Influencing Spectrofluorometry of Phenothiazine Drugs When the drugs are treated with K M n 0 4 , the fluorescence intensity curve increases to a maximum, then decreases again with further treatment. At the appropriate p H , this permanganometric fluorescence titration permitted analysis of 0.002 to 0.02 /ug. of drug per ml. of aqueous solution. THEODORE J . MELLINGER and CLYDE E. KEELER, Department of Neuro-Psychopharmacology, Milledgeville State Hospital, MilledgevMIe, Ga. Anal. Chem. 36, 1840 (1964) VOL. 36, NO. 9, AUGUST 1964
•
15 A
Circle No. 165 on Readers' Service Card
>
