Highlights of the scientific and technical articles in this issue
Gas Chromatography of High Boiling Compounds on Low Temperature Columns Special modification of the column in gas chromatography allows the rapid elution of high boiling compounds at lowered temperatures. The column provides chromatograms showing good resolution and short retention times at temperatures as much as 150' C . below the boiling point of the sample.
Reduction of Noise in Thermal Conductivity Detectors For Gas Chromatography The major part of the noise evident in most gas chromatographs using thermistor detectors arises from sources external to the thermistor and may be eliminated by proper instrument design. The technique described provides about a 50-fold improvement in signal-to-noise ratio.
CHARLES HISHTA, J. P. MESSERLY, and R. F. RESCHKE, Bristol Labaratories, Syracuse, N. Y. Anal. Chem. 32, 1730 f 19601
RICHARD KIESELBACH, E. I. du Pant d e Nemaurs & Co., Inc., Wilmingtan, Del. Anal. Chem. 32, 1749 (1960)
Analysis of Food Flavors by Gas-Liquid Chromatography. Separation and ldentification of the Neutral Components from Bread Pre-ferment Liquid
Rapid Gas Chromatographic Method for Determination of Carbon and Hydrogen
The ether soluble neutral components in pre-ferment brew are isolated and identified by gas-liquid chromatography. Initial identification is made for ethyl formate, y-butyroacetone, 1,3-propanediol-monoacetate,and Pphenylethanol. The most concentrated compounds are ethanol and isomers of 2,3-butanediol. D. E. SMITH and J. R. COFFMAN, General Mills, Inc., Minneapolis 13, Minn. Anal. Chem. 32, 1733 ( 1 960)
A modified gas chromatographic procedure determines carbon and hydrogen contents of organic compounds without the necessity of isolating the products of combustion. Combustion is conducted in an oxygen atmosphere and the oxygen serves as the carrier gas. A single run is completed in 1 7 minutes. A. M. VOGEL and J. J. QUATTRONE, Jr., Adelphi College, G a r d e n City, N. Y. Anal. Chem. 32, 1754 (1960)
Gas Chromatographic Analysis of Chioro methylated Phenyl Ether
Nonaqueous Acidification in Preparation of Organic Acid Concentrates for Gas Chromatography
A gas chromatographic procedure is employed for the
Concentrated anhydrous extracts of organic acids that contribute to food flavors are prepared for gas chromatography analysis. The organic salts are acidified with dichloroacetic acid in acetone. The sodium dichloroacetate precipitates and the free acid is injected into the gas chromatographic column using argon as the carrier gas.
analysis of chloromethylated phenyl ether in mixtures. The sample is processed through a hydrogenolysis step to produce the methyl-substituted phenyl ether, which is quantitatively analyzed by gas chromatography. W. 8. TRAPP, J. 1. PILLEPICH, a n d Midland, Mich.
E. D.
RUBY, The Dow Chemical Co., Anal. Chem. 32, 1737 (19601
Gas Chromatographic Characterization of Fatty Acids. identification Constants for Mono- and Dicarboxylic Methyl Esters A gas-liquid chromatographic technique is employed for the characterization of fatty acids. A scheme is devised whereby each component on the chromatogram is expressed by equivalent chain length (E.C.L.) to a homolog of the saturated straight-chain monocarboxylic acid. The E.C.L. volume is independent of operating conditions. T. K. MIWA, K. 1. MIKOLAJCZAK, F. R. EARLE, a n d I. A. WOLFF, U. S. Department o f Agriculture, Peoria, 111.
I. R. HUNTER, HAWKINS NG, and J. W. PENCE, Western Regional Laboratory, Albany, Calif. Anal. Chem. 32, 1757 ( 1 960)
Determination of Ethylene and Propylene Glycols in Mixtures by Gas Chromatography Ethylene and propylene glycol in mixtures are determined by gas-liquid chromatography. Water and other glycols do not interfere with the determination of these compounds on a 5 7c tetrahydroxyethylethylenediamine o n Chromosorb W column. The procedure indicates a high degree of accuracy. H. G. NADEAU and D. M. OAKS, Olin Mathieson Chemical Corp., N e w Haven, Conn. Anal. Chem. 32, 1760 (1960)
Anal. Chem. 32, 1739 (1960)
Use of a Conventional Mass Spectrometer as a Detector for Gas Chromatography Volatile organic mixtures are analyzed by a combination of mass spectrometry and gas chromatography. The procedure allows the simultaneous determination of several components in chromatographic peaks which contain more than one component. Relative concentrations of components are calculated from mass spectra data. 1. P. LINDEMAN and J. L. ANNIS, California Research Corp., Richmond, Calif. Anal. Chem. 32, 1742 ( 1 960)
Identification of Oxygen Compounds in Gas-liquid Chromatographic Fractions by Catalytic Deoxygenation Catalytic deoxygenation is applied to the identification of oxygen compounds in gas-liquid chromatographic fractions. The oxygen compounds are deoxygenated and the resulting hydrocarbons are isolated and identified. Ketones, aldehydes, alkyl and cyclic ethers, and certain alcohols react smoothly. C. J. THOMPSON, H. J. COLEMAN, R. L. HOPKINS, C. C. WARD, and H. T. RALL, Bureau of Miner, Bartlesville, Okla. Anal. Chem. 32, 1762 ( 1 960)
VOL. 32, NO. 13, DECEMBER 1960
* 13A
Identification of Carbazole in Wilmington Petroleum through Use of Gas-liquid Chromatography and Spectroscopy Gas-liquid chromatography along with mass, infrared, and ultraviolet spectroscopy are used to separate and identify carbazole in virgin petroleum. T w o methods are outlined which confirm the presence of carbazole at a 2 p.p.m. concentration. R. V. HELM-D. R. LATHAM, C. R. FERRIN, and J. S. BALL, Bureau of Mines, Laramie, Wyo. Anal. Chem. 32, 1 7 6 5 ( 1 9 6 0 )
High Temperature Gas-Liquid Chromatography. Exploratory Studies Using an Ionization Detector Chromatograph Certain aliphatic and aromatic organic compounds having boiling points above 500' C. are resolved and determined by gas-liquid chromatography using a special ionization detector. Quantitative and qualitative results indicate good precision and accuracy on the microgram level. 5. J. GUDZINOWICZ and W. R. SMITH, Monsanto Chemicol Co., Everett, Mass.
Anal. Chem. 32, 1 7 6 7 (1960)
Rapid Identification of Cellulose Esters and Ethers Using Paper Chroma tog raphy A paper chromatographic procedure is developed for the rapid detection of cellulose derivatives in commercial materials. Using two separate colorimetric reactions, all derivatives are distinguished exce t methyl- and hydroxyethyl-cellulose. Characteristic fehavior of the derivatives are outlined. E. 8. M A N 0 and L. C. 8. CUNHA LIMA, Instituto Nacional de Tecnologia, Avenida Venezuela, 82-Rio d e Janeiro, Brazil Anal. Chem. 32, 1 7 7 2 (1960)
Chromatographic Estimation of Sugars in Wood Cellulose Hydrolyzates. A Routine Reflectance Method The sugar content of wood cellulose hydrolyzate is determined without uronic acid interference. Paper chromatograms are obtained and the reflectance of the colored sugar spot is measured directly. Concentrations are calculated from a plot of Mubelka-Munk K/S values vs. per cent sugar concentration of standard solutions. J. E. JEFFERY, E. V. PARTLOW, and W. J. POLGLASE, Rayonier In. corporated, Shelton, Wash. Anal. Chem. 32, 1 7 7 4 (1 9 6 0 )
ote on the Theory of Solid Phase Diffusion in Chromatography Theoretical treatment is rendered to the problem of transient diffusion into a single sphere exposed to a gaussian concentration pulse at its surface as a means of simulating the mass transfer problem in elution chromatography. D. C. BOGUE, University of Delaware, Newark, Del.
Ion Exchange Chromatography of Amino Acids. Analysis of Diffusion (Mass Transfer) Mechanisms Underlying mechanisms to extend the usefulness of the theoretical approach are examined for the chromatographic separation of certain amino acids by elution from a Dowex 5O-XS ion exchange column. Precise delineations are given for the effects of column variables on the chromatogram form. Certain variables require close control to ensure reproducible results. P. B. HAMILTON, D, C. BOGUE, and R. A. ANDERSON, University of Delaware, Newark, Del. Anal. Chem. 32, 1 7 8 2 ( 1 9 6 0 )
Photometric Titration of Weak Acids in Nonaqueous Media. Determination of Phenols in Isopropyl Alcohol Phenols and other weak acids are quantitatively determined by nonaqueous photometric titration procedure. The sample is dissolved in isopropyl alcohol and titrated with tetra-n-butylammonium hydroxide at various wave lengths. Titration curves give evidence for the formation of strong hydrogen bonds between phenols and phenolate ions. L. E. I. HUMMELSTEDT and D. N. HUME, Massachusetts Institute of Technology, Cambridge 39, Mass. Anal. Chem. 32, 1 7 9 2 (1 960)
Spectrophotometric Determination of Cyanamide Cyanamide in blood, urine, and soil is determined by spectrophotometric procedure. The sample is reacted with pentacyanoammineferrate in a carbonate buffer at pH 10.5 The color produced is measured at 5 3 0 mG. The usual impurities and additives found in cyanamide preparations do not interfere. D. A. BUYSKE and VINCENT DOWNING, American Cyanamid Co., Pearl River, N. Y. Anal. Chem. 32, 1 7 9 8 (1960)
Spectrophotometric Determination of Chlorate Impurities in Ammonium Perchlorate. Determination of Reducing and Oxidizing Impurities in Hydrochloric Acid Chlorate impurity in ammonium perchlorate samples is determined by spectrophotometric procedure. The chlorate reacts with benzidine in hydrochloric acid medium producing a colored haloquinone. The maximum absorbance is measured at 438 mp. With the same technique oxidizing and reducing impurities in reagent grade hydrochloric acid are calculated. E. A. BURNS, California Institute of Technology, Pasadena, Calif, Anal. Chem. 32, 1 8 0 0 (1960)
Anal. Chem. 32, 1777 ( 1960)
!on Exchange Chromatography of Amino Acids. Study sf Effects of High Pressures and Fast Flow Rates Glass columns suitable for operation at elevated pressures and pum connections to them are designed for ion exchange cgromatography of amino acids. Flow rates up to 0.17 cm. sec.-l with pressures as high as 600 p.s.i. are realized. Multisectional columns are constructed incorporating these features. P. B. HAMILTON, Alfred I. du Pont Institute of the Nemourr Foundution, Wilmington 99, Dei. Anal. Chem. 32, 1 7 7 9 ( 1 9 6 0 )
A N e w Spectrophotometric Procedure Microdetermination of Methyl Chloride
for
the
Micro-amounts of methyl chloride are determined by spectrophotometric procedure based on the Pujiwara reaction for chloroform. The method is sensitive but not specific, all alkyl halides react. Methyl chloride indicates a maximum absor tion peak at 365 mM. Other alkyl halides give single pea$ between 360 and 3 7 5 mp. MARGARET REDFORD-ELLIS and J. E. KENCH, Manchester University, Manchester, England Anal. Chem. 32, 1 8 0 3 (19601
VOL. 32, NO. 13, DECEMBER 1960
a
15A
Spectrophotometric Determination of Selenium in Steroids Qrganic selenium compounds as contaminants in steroids are determined spectrophotometrically. Selenium is separated from the organic compound and oxidized with nitric acid. The selenous acid produced reacts with o-phenylenediamine to form a compound which indicates a maximum absorbance at 3 30 mp. h. J. THROOP, Syntex,
S. A.,
Mexico, D. F., Mexico Anal. Chem. 32, 1 8 0 7 ( 1 940)
Characteristic Constants of 2,2',4~-Trihydroxyazobenzene-5-sulfonic Acid, a Reagent for Spectrophotometric Analysis Basic data pertaining to the dye, 2,2',4'-trihydroxyazobenzene-5-sulfonic acid, as a reagent for determining zirconium are presented. Four principal dye species are indicated and are used with ionization constants to calculate the approximate absorption spectrum for any dye solution in a certain acidity range. M. H. FLETCHER, U. S. Geological Survey, Washington, D. C. Anal. Chem. 32, 1 8 2 2 ( 1 960)
Speetrophotometric Determination of Sterculic Acid A spectrophotometric procedure based on the Halphen test for cyclopropene structure is used to determine sterculic acid in cottonseed oil. The sample is reacted with carbon disulfide-sulfur reagent in pyridine and the absorbance measured at 5 0 5 mp. A. J. DEUTSCHMAN, Jr., and I. S. KLAUS, University of Arizona, Tucson, Ariz. Anal. Chem. 32, 1809 (1 960)
Determination of Additives in Polyethylene by Absorption Spectroscopy
A rapid and accurate method determines certain thermal antioxidant additives in commercial polyethylene. The
Theoretical Study of the Reacfion between 2,2',4'Trihydroxyazobenzene-5-sulfonic Acid and Zirconium Theoretical studies are made pertaining to the reaction between zirconium and the dye, 2,2 ',4'-trihydroxyazobenzene-5-sulfonic acid. T w o chelates are formed with dye to zirconium ratios of 1 to 1 and 2 to 1. Fundamental data are given to serve as a basis for any specific application of the reaction. M. H. FLETCHER, U. S. Geological Survey, Washington, D. C. Anal. Chem. 32, 1 8 2 7 (1 9601
powdered sample is extracted with a suitable solvent at room temperature. The extract is examined by infrared or ultraviolet spectrometry and the concentrations calculated. The method is used to determine impurities in pdyethylene,
Extraction and FBame Photometric Determination of
H. L. SPELL and R. D. EDDY, The Dow Chemical Co., Freepod, Tex. Anal. Chem. 32, 1 8 1 1 11960)
etermination of Tetramethyllead and Tetraethyllea in Gasoline by Mass Spectrometry A rapid analysis of gasoline for tetramethyl-and/or tetraethyllead is accomplished by a mass spectrometric procedure. The mass spectrum of the sample is comEared with the mass spectrum of two synthetic blends of nown concentrations of tetramethyl- and tetraethyllead. H. E. HOWARD, W. C. FERGUSON, and of California, Brea, Calif.
L. R.
SNYDER, Union:Oil
laon The iron content of several materials is determined by extraction into an organic solvent and measuring the concentration by flame photometry. The iron i s extracted from hydrochloric acid solution with 4-methpl2-pentanone and the emission intensity measured at 3 7 2 mp. Chromium (VI), molybdenum, and tin interfere at concentrations of 150 times that of iron. OSCAR hENIS and T. C. RAINS, O a k Ridge National l a b o r a t o r y , O a k Ridge, Tenn. Anal. Chem. 32, 1 8 3 7 ( 1 960)
Co.
Anal. Chem. 32, 1 8 1 4 (1960)
lnetrumentd Measurement of Total lonizatkm in the Mass Spectrometer Direct measurement of a signal proportional to the amount of sample charged in mass spectrometry 1s obtained by special instrumentation. Design requirements for direct measurements of total ionization in a mass spectrometer are outlined. Preliminary data afford evidence of its value in analytical mass spectrometry.
uelitative Test for Glycine A qualitative test is developed for determining glycine. When glycine is mixed with ethyl chloroformate and pyridine is added dropwise, a dark green color develops which turns red upon standing. Glycine derivatives give a positive response. The test is also specific for pyridine and alkyl chloroformates. R. I.. SUBLETT and J. P. JEWELL, Tennessee Polytechnic Institute, Cookeviile, Tenn. Anal. Chem. 32, 1 8 4 1 ( 1 960)
H. E. LUMPKIN and J. 0. BEAUXlS, Humble Oil & ReRning Co., Baytown, Tex. Anal. Chem. 32, 181 5 (1 960) Correlation of Mass Spectra with Structure in Arematic Oxygenated Compounds. Aromatic Alcohols and Phenols
An investigation is made of the correlations existing between the mass spectra and the chemical structure of several aromatic alcohols and phenols. Spectral features are correlated to the stability and fragmentation pattern of the benzenic ring, and to the nature, number, and position of groups substituted on the ring. THOMAS ACZEL and town, Tex.
H. E.
LUMPKIN, Humble Oil 8, Refining Ca., BayAnal. Chem. 32, 1 8 19 ( I 960)
Spectrophotometric Methods for Olefins. Colorimetric Determination of Conjugated Diolefins A convenient and sensitive colorimetric procedure is used to determine isoprene and similar diolefins. The conjugated diolefins are reacted with p-nitrobenzenediazonium fluoborate in a 2-methoxyethanolphosphoric acid solvent. The isoprene complex absorbs at 490 mp, and the butadiene complex at 405 mp, The method is applied to air mixtures and liquid hydrocarbon solutions. A. P. ALTSHULLER and 1. R. COHEN, Public Health Service, Cincinnati 26, Ohio Anal. Chem. 32, 1 8 4 3 ( 1 960)
VBL. 32, NO. 13, DECEMBER 1960 e
17
The Graphite Electrode. A n smproved Technique for Voltammetry and Chronopotentiometry A new methodological refinement of the graphite electrode used in voltammetry and chronopotentiometry involves the use of a surface-active agent to ensure complete wetting of the electrodes by the test solution. Evaluation data are obtained for several electroactive s ecies and results compare favorably with those inicated with platinum electrodes.
2
P. J. ELVING and D. L. SMITH, University of Michigan, Ann Arbor, Mich. Anal. Chem. 32, 1 8 4 9 11 9 6 0 )
Coulometry with the Carbon Black Electrode Electroactive organic compounds of low water solubility are analyzed by direct constant current coulometry using a carbon black electrode. The method is based o n the quantitative adsor tion of the electroactive material onto an acetylene blact electrode, and the subsequent electrolysis at constant current or controlled potential. J. D. VOORHIES and Brook, N. J.
S. M.
DAVIS, American Cyanamid Co.,
Bound
Anal. Chem. 32, 1855
I19 6 0 )
I I I
automatically records rhe conductance of a sample solution as a function of the volume of titrant added. The range of the instrument may be adjusted to suit the sample, permitting each ticration to occupy the full width of the recorder, resulting in maximum sensitivity. D. W. COLVIN and R. C. BROPST, E. I. du Pont de Nemours and Co., Aiken, S. C. Anal. Chem. 32, 1858 ( 1 9 6 0 ) R
Improved Alpha-Counting Technique
A new alpha-counting technique uses a zinc sulfide phos hor which permits uniform high efficiency and low &ackground. The sample as mounted is completely enclosed and cannot transfer activity to rhe counter, and can be easily stored for recounting without fear of loss or cross contamination.
N.
A. HALLDEN and J. New York 14, N. Y.
H.
HARLEY, U.
S. Atomic
Energy Commission,
Anal. Chem. 32, 1861 ( 1 9 6 0 )
eterrninaliion of Uranium and Plutonium in Uranlusn-PsutQsPium-Fission Element Alloys Uranium and plutonium are separated from fission element alloys and from each other by tributyl phosphatehydrochloric acid extraction. For analysis of uranium the x-ray spectrometric method is applied, and for plutonium the spectrophotometric measurement of the nitrate complex ion is used. Coefficients of variation for determinations of uranium and plutonium were 0.5 and 0.8%, respectively. R. P. LARSEN and 6. A. SEILS, Jr., Argonne National Laboratory, Argonne, Ill. Anal. Chem. 32, 1863 ( 1 9 6 0 )
q
~ Son Exchange e ~ Separation ~ ~Scheme ~ for ~ d Mefaliic Radioelements
k sequential ion exchange group separation scheme is designed for the rapid separation of tracer amounts of 3 5 metallic radioelements into smaller groups. The solution is particularly treated and applied to a Dowex50W column. The elements are eluted by a series of complexing elements at controlled p H and ionic strength. W. J. BLAEDEL and E. D. OLSEN, University of Wisconsin, Madison, Wis,, and R. F. BUCHANAN, Argonne National Laboratory, Lemont, 111. Anal. Chem. 32, 1 8 6 6 ( 1 9 6 0 )
Plutonium
in
Plutonium is separated from uranium-fission product mixtures by a two cycle extraction procedure. After the three actinides are extracted into methyl isobutyl ketone, plutonium is stripped by contact with an aqueous phase containing a reductant. Plutonium is oxidized and a final extraction made into thenoyltrifluoroacetone-xylene.
I I
W. J. MAECK, G. L. BOOMAN, M. E. KUSSY, and J. E. REIN, Phillips Petroleum Co., Idaho Falls, Idaho Anal. Chem. 32, 1874 ( 1 9 6 0 )
I I I I I I I I
I I I I
I 1
I
I I L
A recording conductometric titrator is described which
Determination of Product Mixtures
I I
I A Recording Conductometric Titrator
Separation and Uranium-Fission
1 I I
s
I 1 1 I
s
1 I I I 1
Selective Precipitation ob Silver Halides from Homogeneous Solution. Separation of loelide, Bromide, and Chloride Using Volatilization of Ammonia Silver halides in homogeneous solutions are separated by selective precipitation. The sample solution containing concentrated ammonium hydroxide is heated and the ammonia is evolved under controlled conditions. Silver iodide, silver bromide, and silver chloride precipitate in this order as the ammonia evolves and are filtered off separately. F. H. FIRSCHING, University of Georgia, Athens, Ga. Anal. Chem. 32, 1875 ( 1 9 6 0 )
Trialkyl Thiophosphates. Selective Extractants for Silver and Mercury The use of triiso-octyl thiophosphate or of tri-n-butgi thiophosphate as extracting agents has revealed a high degree of selectivity for silver and mercury(I1) from a nitric acid medium. The influence of certain variables, such as concentrations, temperature, diverse ions, and salting ions is investigated. Solvate structures are presented for reaction between reagent, nitric acid, and metal nitrates. T. H. HANDLEY, Oak Ridge National Laboratory, Oak Ridge, Tenn., and J. A. DEAN, University of Tennessee, Knoxville, Tenn.
I
I I I I I I
I I I
I I I I I I I I I I I I I 1 I I I I
I I I I I I I
s
Anal. Chem. 32, 1878 ( 1 9 6 0 )
Rapid Electrophoresis of Alkaloids Agar gel electrophoresis in an unequilibrated system makes possible a much more ra id, accurate meam for separation and determination o f alkaloids encountered in toxicological examination of autopsy materials. This system, which uses an underlay of vegetable parchment, is faster, easier to use, and gives better resolving power than paper chromatography o r paper electrophoresis. L. A. WILLIAMS, Y. M. BRUSOCK, and BENNIE ZAK, Wayne State University, Detroit 7, Mich. Anal. Chem. 32, 1883 ( 1 $ 6 0 )
Volumetric Determination of Germanium A titrimetric method is developed for determining macro amounts of germanium. The sample is dissolved in'hydrochloric acid and distilled; the distillate is reduced with hypophosphate. Germanium is titrated directly with KIOs-KI solution to a starch indicator endqpoint. G. J. ABEL, Jr., American Smelting and Reflning Co., South Plainfleld, N. J. Anal. Chem. 32, 1 8 8 6 ( 1 9 6 0 )
A Modifled Tin-Flux Technique for Determination of Oxygen in Titanium A tin-flux procedure is developed as a modification of the Walter method for determining oxy en in titanium; The modification provides extraction ofoxygen a: 1950 C . in a graphite crucible and conditions for rapid 'degassing of the crucible assembly. CH. VENKATESWARLU and M. W. MALLETT, Battelle Memorial Institute, Columbus 1, Ohia Anal. Chem. 32, 1888 (1960)
VOL. 32, NO. 13, DECEMBER 1960
e
19A
