AC BRIEFS Highlights of the scientific and technical articles in this issue
Determination of Boron in Beryllium, Zirconium, Thorium, and Uranium. Dissolution in BromineMethanol
A precise and accurate spectrophotometric method is used to determine microgram quantities of boron in metals. The sample is dissolved in bromine-methanol solution and the boron ester separated by distillation. A color complex is developed with diaminochrysazin and the absorbance measured at 52 5 πΐμ. A. R. EBERLE and M . W . LERNER, U. S. Atomic Energy Commission, New Brunswick, N. J. A n a l . Chem. 3 2 , 1 4 6 ( 1 9 6 0 )
Determination of Uranium(VI) Uranium(lll) in a Jones Reductor
by
Reduction
to
Uranium(VI) is quantitatively determined by reduction in a Jones reductor and the resulting uranium (III) titrated with potassium dichromate. The reduction is accom plished in \M hydrochloric or perchloric acid, provided the uranium concentration is below 0.01ΛΙ. Ûranium(III) is added to an iron(III) solution, reducing it to iron (II) which is then titrated with potassium dichromate. J. H. KENNEDY, E. I. du Pont d e Nemours & Co., Inc., W i l m i n g t o n , Del.
Direct A m i n o Acid Analysis by Gas raphy
Chromatog
A direct gas chromatographic method is devised for de termining amino acids that yield volatile aldehydes. The sample is injected into the continuous flowing sys tems where the amino acids are oxidized. The aldehydes are chromatographically separated, catalytically cracked, and analyzed in a thermal conductivity cell. ALBERT ZLATKIS, J. F. O R O , and A. P. KIMBALL, University of Houston, Houston, Tex. A n a l . Chem. 3 2 , 1 6 2 ( 1 9 6 0 )
Gas-Liquid Chromatography of Pyridines Using a N e w Solid Support
Symmetric peaks are obtained in the chromatography of pyridines when nonpolar substrates are used with a new solid support. The solid support is prepared from a commercial detergent by heating and extracting with pe troleum ether. Retention data were obtained for 15 pyridines using 10 liquid substrates on the new solid sup port. A. W . DECORA and G . U. DINNEEN, U. S. Department of Interior, Laramie, W y o . A n a l . Chem. 3 2 , 1 6 4 ( 1 9 6 0 )
A n a l . Chem. 3 2 , 1 5 0 ( 1 9 6 0 )
Determination of Iodine in Thallium(l) Iodide Precipitates
The iodine content of thallium(I) iodide precipitates is quantitatively determined. The procedure is based on the fact that thallium (I) and iodide are oxidized with bromine, but thallium (III) is not reduced with formic acid and liberates iodine, which is titrated with sodium thiosulfate. E D W A R D JEUNG Berkeley, Calif.
and
Ε. Η.
HUFFMAN,
University
of
California,
A n a l . Chem. 3 2 , 1 5 2 ( 1 9 6 0 )
Determination of Chemically Combined Iodine in Sea Water by Amperometric and Catalytic Methods
Two methods for the determination of chemically com bined iodine are examined for analysis of sea water. An amperometric method determines iodine as iodate and iodide, while a catalytic method accurately determines total iodine. In combination the methods quantitatively measure the total iodine content of relatively small sam ples in a short span of time. R. A. BARKLEY and T. G . T H O M P S O N , University o f Washington, Seattle, W a s h . A n a l . Chem. 3 2 , 1 5 4 ( 1 9 6 0 )
Factors Affecting the Use of Gas-Liquid Chromatog raphy for the Separation of Large Samples. Sample Inlet System, Distribution Coefficient of Solute, and Amount of Liquid in Stationary Phase
A systematic study is made regarding optimum condi tions for operation of columns in gas-liquid chromatog raphy. Large samples should be introduced in con centrated form, as column efficiency decreases as sample volume increases. It is important to use large amounts of liquid in the stationary phase. W . J. de WET, a n d Pretoria, South Africa
VICTOR
PRETORIUS, University of
Pretoria,
A n a l . Chem. 3 2 , 1 6 9 ( 1 9 6 0 )
Ultraviolet Determination Nitrite Ion
of Nitrogen Dioxide as
An ultraviolet spectrophotometric procedure is developed for determining nitrogen dioxide in nitrogen gas. Nitrogen dioxide is converted to nitrite ion by absorption in alkaline potassium or sodium hydroxide solutions. The optical absorbance of the nitrite ion is measured at 355 mM. A. P. ALTSHULLER a n d A. F. WARTBURG, U. S. Department o f Health, Education, a n d W e l f a r e , Cincinnati 2 6 , O h i o A n a l . Chem. 3 2 , 1 7 4 ( 1 9 6 0 )
Quantitative Analysis of Acetic Acid-Acetic A n hydride Mixtures in the Near-Infrared Region. A Statistical Study
Acetic acid concentrations up to 10% in mixtures with acetic anhydride are rapidly determined by a spectro photometric procedure. The untreated sample is scanned between 1600 and 1450 ηΐμ, and the results are calculated from the spectrum. Analysis time is about 6 minutes per sample. J. E. FERNANDEZ, R. T. McPHERSON, G . K. FINCH, a n d B O C K M A N , Tennessee Eastman Co., Kingsport, Tenn.
C.
Classification of Fine Structural Characteristics in Cellulose by Infrared Spectroscopy. Use of Po tassium Bromide Pellet Technique
Infrared spectroscopy is used as the basis for a routine analytical method for classifying cellulose samples ac cording to their fine structural characteristics. The effect of mercerization on the infrared spectrum is studied using the potassium bromide pellet technique.
D.
A n a l . Chem. 3 2 , 1 5 8 ( 1 9 6 0 )
F. G . HURTUBISE a n d HANS KRASSIG, Industrial Cellulose Research, Ltd., Hawkesbury, O n t a r i o , C a n a d a A n a l . Chem. 3 2 , 1 7 7 ( 1 9 6 0 )
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BRIEFS Qualitative and Quantitative Analysis of Organic Compounds. Use of Low-Voltage Mass Spectrom etry
A low-voltage mass spectrometric procedure is used for qualitative and quantitative analysis of multicomponent mixtures. The method eliminates the use of simultane ous equations in quantitative calculations and has pre cision and accuracy equivalent to normal mass spec trometric analysis. Fragment ions and low sensitivities molecule-ion types interfere.
Rapid Test for Identification Phenylenediamine
of the
Isomers
of
A qualitative procedure is described for differentiating between o-, m-, and /(-phenylenediamine. Based on the phosphotungstic acid method, if the solution is not buffered and phosphomolybdic acid is used, color complexes are formed relative to the position of the amine group on the benzene ring. R. G. FR1ESER and P. A. SCARDAVILLE, Interchemical Corp., New York 3 6 , N.Y.
C. J. VARSEL, F. A. MORRELL, F. E. RESNIK, and W . A. POWELL, Philip Morris, Inc., and University of Richmond, Richmond, V a . Anal. Chem. 3 2 , 1 8 2 ( 1 9 6 0 )
Anal. Chem. 3 2 , 1 9 6 ( 1 9 6 0 )
N e w Color Test for Heroin Determination of Sodium Ions in Acidic Silica Sol Systems. Solution Potentiel Measurement Procedure
A simple electrode assembly is applied for determining small amounts of sodium ion in acid silica sols. The sample is diluted and passed over an anion exchange resin to adjust to optimum pH. Potential measurements are conducted on the effluent and the sodium ion content is calculated.
A new colorimetric method is described for determining heroin. The sample, dissolved in a small amount of chloroform, is reacted with a nitric-phosphoric acid mixture. A color from yellow to red-brown develops, depending on the heroin concentration. MELVIN LERNER, U. S. Customs Laboratory, Baltimore, M d . Anal. Chem. 3 2 , 1 9 8 ( 1 9 6 0 )
T. A. TAULLI, Monsanto Chemical Co., St. Louis, Mo. Anal. Chem. 3 2 , 1 8 6 ( 1 9 6 0 )
Ultraviolet Spectrophotometry of Serum Proteins Rapid Determination of Fluoride in Silica-Alumina Catalyst by Steam Hydrolysis
A pyrohydrolysis method is developed for determining fluorine in silica-alumina catalyst and other silica-bearing material. The sample is hydrolyzed in a quartz tube and the liberated hydrogen fluoride is collected and titrated with thorium nitrate, using sodium alizarin sulfonate as the indicator. L. W . GAMBLE, W . E. PRICE, and W . H. JONES, Esso Standard Oil Co. Baton Rouge, La. Anal. Chem. 3 2 , 1 8 9 ( 1 9 6 0 )
Analytical Assay of Diosgenin
Crude diosgenin is assayed by a fractional sublimation technique. A sample is sublimed under high vacuums at 180° C ; diosgenin and volatile impurities sublime, leaving a residue. Resublimation at 160° C. removes the impurities, leaving essentially pure diosgenin. The re sults compare favorably with column chromatography and countercurrent distribution results. STEPHEN K A U F M A N N , J. C. MEDINA, and CLAUDIO ZAPATA, Syntex, S. Α., Mexico City, Mexico Anal. Chem. 3 2 , 1 9 2 ( 1 9 6 0 )
Ultraviolet spectrophotometry is employed to estimate serum protein fractions separated by electrophoresis. Tyrosine and tryptophan are especially determined in the fractions, but results from 11 fractions of 12 normal sera indicated wide variations rendering the ultraviolet method of quantitating proteins unacceptable. R. D. STRICKLAND, P. A. MACK, T. R. PODLESKI, and W . A. CHILDS, Veterans Administration Hospital, Albuquerque, Ν. Μ. Anal. Chem. 3 2 , 1 9 9 ( 1 9 6 0 )
Potassium Phosphate as a Reagent for the Gravi metric Estimation of Lithium
The gravimetric determination of lithium as orthophos phate is modified to enhance the quantitative response greatly. The sample is reacted with potassium phosphate in a medium of 60% ethanol. After filtration and wash ing, the precipitate is ignited between 650° and 700° C. C. C. PATEL and K. N. VISHWESHWARAIAH, Indian Institute of Science, Bangalore 1 2 , India Anal. Chem. 3 2 , 2 0 2 ( 1 9 6 0 )
Analytical Reagents. A N e w Reagent for
Spectrophotometric Determination of V a n a d i u m as Tungstovanadic Acid
A gravimetric method for determining palladium uses 2thiophene-inzwi-aldoxime as the precipitating reagent. In acid solution the reagent forms a light yellow, coor dinating complex which is very stable and easily filtered. The method is also used to separate palladium from diverse ions.
A spectrophotometric method is described for deter mining vanadium as tungstovanadic acid. The sample is condensed with oxyacids of tungsten(VI) forming a colored complex with maximum absorbance at 392 αιμ. Chromium seriously interferes and must be separated. The interference of iron is eliminated by fluoride complexation.
Thiophene Derivatives as 2-Thiophene-frans-aldoxime, Palladium
S. G . T A N D O N and S. C. BHATTACHARYA, National Chemical Labora tory, Poona, India Anal. Chem. 3 2 , 1 9 4 ( 1 9 6 0 )
G. W . WALLACE with M. G . MELLON, Purdue University, Lafayette, Ind. Anal. Chem. 3 2 , 2 0 4 ( 1 9 6 0 )
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BRIEFS Polarography of Thiocyanate Ion. Formation with Mercury(ll) Ion
Complex
Ion
Anodic p o l a r o g r a p h i c oxidation of mercury in solutions of thiocyanate is investigated over a wide r a n g e of con centrations. Formation constants, K-·, Ks, and Kt, are reported for the complex ion formed between thio cyanate and mercury(II), K, = (1.18 ± 0.08) X 10 16 ; K3 = (8.9 ± 0.8) X 10 18 ; and Kt = (8 7 ± 0.6) X 102». C. J. N Y M A N a n d G . S. ALBERTS, Washington State University, Pullman, Wash. Anal. Chem. 3 2 , 2 0 7 ( 1 9 6 0
Some Factors Affecting Flame Photometric Emission of Rubidium in an Oxygen-Acetylene Flame T h e flame photometric characteristics of rubidium are studied in the presence of large amounts of potassium and other cations. T h e rubidium line at 780 mji is increased by overlapping of emission from the 770 ταμ potassium line. Background subtraction is necessary for correction Lithium is used as an internal control. T. E. SHELLENBERGER, R. E. PYKE, D. B. PARRISH, and W . G . SCHRENK' Kansas Agricultural Experiment Station, M a n h a t t a n , Kan. A n a l . Chem. 3 2 , 2 1 0 ( 1 9 6 0 )
Determination of Traces of V a n a d i u m , Iron, and Nickel in Petroleum Oils by X - R a y Emission Spec trograph/ X-ray emission s p e c t r o g r a p h ^ technique is used for determining vanadium, iron, and nickel in residual petroleum stocks. Using a 4-ml. sample, the method accurately estimates the metallic concentration to ± 1 p.p.m., requiring only 40 minutes for the analysis. CHIA-CHEN CHU K A N G , E. W . KEEL, and ERNEST S O L O M O N , The M. W . Kellogg Co., Jersey City, N. J. Anal. Chem. 3 2 , 2 2 1 ( 1 9 6 0 )
Precision Null-Point chemiral Analysis
Atomic
Absorption
Spectro-
A new, sensitive, selective, and reliable spectrochemical technique and instrument are described for the quanti tative determination of elements such as sodium and potassium. T h e concentration of element in the refer ence is varied continuously until the intensity of trans mitted specific radiation to the detector is the same for both reference and u n k n o w n vapors. H. V. MALMSTADT Urbana, III.
and
W.
E. CHAMBERS, University
of
Illinois
Anal. Chem. 3 2 , 2 2 5 ( 1 9 6 0 )
and
Refractometric Determination of Mutual Solubility as a Function of Temperature. Tributyl Phosphine Oxide and Water
Oxamidoxime is used as a specific reagent for the spectro photometric determination of nickel and cobalt in mix tures with diverse ions. Nickel is precipitated with oxa midoxime, while cobalt forms a color complex. T h e cobalt complex is measured at 3 50 m,u; the nickel precipitate is dissolved in hydrochloric acid and its absorbance measured at 233 ηΐμ.
Refractometric techniques are used to determine solu bility in binary mixtures over a wide temperature range. T h e solubilities of tributyl phosphine oxide in water and water in tributyl phosphine oxide are determined by measuring refractive indices. Both solubilities are in versely temperature-dependent, increasing as the tem perature drops.
G . A. PEARSE, Jr., and R. T. PFLAUM, State University of Iowa, Iowa City, Iowa
C. E. H I G G I N S and W . H. B A L D W I N , O a k Ridge National L a b o r a t o r y , O a k Ridge, Tenn.
A n a l . Chem. 3 2 , 2 1 3 ( 1 9 6 0 )
Anal. Chem. 3 2 , 2 3 3 ( 1 9 6 0 )
Determination of Iron and Iron-Aluminum Mixtures by Titration with EDTA
Effect of Centrifugation on Solution Temperature and Solubility of Tributyl Phosphate and Tributyl Phos phine Oxide in Water »
T h e titration of iron with EDTA is accomplished in the presence of aluminum. T h e aluminum interference is eliminated by adjusting the solution to p H 1.0. T h e end point is measured spectrophotometrically at 510 m/x, recording the disappearance of the iron-sulfosalicylic complex formed by using 5-sulfosalicylic acid as an indicator.
In analytical procedures involving centrifugation signifi cant temperature change affects solution equilibrium. Water saturated 'with tributyl phosphate and tributyl phos phine oxide, centrifuged at 2 5° C , indicated a 14° rise in temperature. It is recommended that centrifugation with air cooling be employed.
D. G . DAVIS a n d W . R. JACOBSEN, G e o r g i a Institute of Technology, Atlanta 1 3, G a .
C. E. H I G G I N S and W . H. B A L D W I N , O a k Ridge National Laboratory, O a k Ridge, Tenn.
Spectrophotometric Determination Nickel with Oxamidoxime
of
Cobalt
Anal. Chem. 3 2 , 2 1 5 ( 1 9 6 0 )
Carbon-Hydrogen Stretching Frequencies
Anal. Chem. 3 2 , 2 3 6 ( 1 9 6 0 )
Radioassay of Finely Divided Solids by Suspension in a Gel Scintillator
T h e spectra of 10 cyclobutyl compounds and 60 aro matic compounds are investigated and correlated in the carbon-hydrogen stretching region of 2700 to 3100 c m . " ' , using a lithium fluoride prism. T h i s informa tion is of value in spectra-structure correlation studies of related materials.
T h e counting characteristics of a wide variety of sus pended beta-emitting radioactive materials in gel scin tillator medium are described. In application the advantages of suspension over homogeneous solution are illustrated. Among the radioéléments involved are strontiumj0O, chlorine-36, carbon-14, and hydrogen-3.
S. E. WIBERLEY, S. C. BUNCE, and W . H. BAUER, Rensselaer Polytechnic Institute, Troy, Ν. Υ.
SAMUEL HELF, C. G . WHITE, and R. N. SHELLEY, Picatinny Arsenal, Dover, N. J.
A n a l . Chem. 3 2 , 2 1 7 ( I 9 6 0 )
Anal. Chem. 3 2 , 2 3 8 ( 1 9 6 0 )
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BRIEFS Isolation of the Rare Earth Elements. tion-Volatilization Procedure
A Chlorina-
Carbon-Hydrogen Determination by Gas Chroma tography
Rare earth elements are isolated from radioactive ores and concentrates containing uranium and thorium by a chlorination-volatilization procedure. The sample is totally chlorinated and volatilized at 900° C. followed by precipitation with ammonium hydroxide, leaving the pure rare earth elements. With large amounts of uranium and thorium preliminary extraction from nitric acid medium with tributyl phosphate—carbon tetra chloride is required.
A gas-solid chromatographic procedure is devised for determining carbon-hydrogen in organic compounds. The sample is burned, forming carbon dioxide and water. The water is converted to acetylene and the two gases are separated and detected in a column and thermal conductivity cell, respectively. Concentrations are calcu lated from peak areas on the chromatogram.
J. B. ZIMMERMAN and J. C. INGLES, Department of Mines and Technical Surveys, O t t a w a , C a n a d a Anal. Chem. 3 2 , 2 4 1 ( 1 9 6 0 )
Direct-Reading Spectrochemical Fluorine in A l u m i n a
Determination
A. A. DUSWALT and W . W . BRANDT, Purdue University, Lafayette, Ind. Anal. Chem. 3 2 , 2 7 2 ( 1 9 6 0 )
of
The sensitivity and reproducibility of one SrF and two CaF band heads were compared, using several mixtures and excitation conditions. Best results are obtained with equal parts of sample, strontium carbonate, and graphite, excited in air by a 6-ampere d.c. arc.
Application of Gas Chromatography to Microdetermination of Carbon and Hydrogen
P. E. LEMIEUX and R. H. BLACK, Aluminium Laboratories, Ltd., Arvida, Quebec, Canada Anal. Chem. 3 2 , 2 4 6 ( 1 9 6 0 )
Micro amounts of carbon and hydrogen are determined by a gas chromatographic technique. Organic com pounds are converted to carbon dioxide and water by combustion and the water is chemically converted to acetylene. Carbon dioxide and acetylene are separated on a silica gel column and detected by thermal conductivity. The concentrations are recorded in terms of peak areas.
Metal Chelate Stability Constants of Aminopolycarboxylate ligands
O . E. SUNDBERG and CHARLES MARESH, American Cyanamid Co., Bound Brook, Ν J. Anol. Chem. 3 2 , 2 7 4 ( 1 9 6 0 )
The chelate stability constants are measured potentiometrically with a mercury electrode for a series of divalent metal ions and certain aminopolycarboxylate ligands. The various chelons are compared on the basis of log Κ values only, with no reference to the effects of pH. J. H. HOLLOWAY and C. N. REILLEY, University of North Carolina, Chapel Hill, N. C. Anal. Chem. 3 2 , 2 4 9 ( 1 9 6 0 )
A Digitizing Print-Out Mechanism. Capable of Automatically Carrying Out Simple Mathematical Conversions
The construction of a digitizing print-out mechanism is described, which automatically converts from a linear to a logarithmic scale the readings given by a self-balancing photometer. The mechanism is general and versatile in application and costs about one sixth as much as a multi point recorder. D. H. S I M M O N D S and R. J. R O W L A N D S , University of Adelaide and Commonwealth Scientific and Industrial Research Organization, A d e laide, Australia Anal. Chem. 3 2 , 2 5 6 ( 1 9 6 0 )
Automatic Equipment for Simultaneous Determina tion of A m i n o Acids Separated on Several Ion Exchange Resin Columns
Automatic equipment is described which estimates the amino acid composition of up to eight different samples simultaneously. The equipment controls the operation of eight ion exchange chromatographic columns, and presents the results from each as a printed record. Six analyses for common amino acids are completed in 48 hours. D. H. S I M M O N D S and R. J. ROWLANDS, University of Adelaide, and Commonwealth Scientific and Industrial Research Organization, Victoria, Australia Anal. Chem. 3 2 , 2 5 9 ( 1 9 6 0 )
Photometer for Continuous Determination of Uranium in Radioactive Process Streams
A filter-type photometer employing a single light path and a single light intensity detector is used for the continuous determination of uranium in radioactive process streams. The instrument offers simplicity in operation and minimizes the problems of radiation exposure to personnel. F. A. SCOTT and R. D. DIERKS, General Electric Co., Richland, Wash. Anal. Chem. 3 2 , 2 6 8 ( 1 9 6 0 )
Determination of Micro Quantities of Boron in Steel by a Solvent Extraction Method
A solvent extract procedure is developed for determining trace amounts of boron in steel. Boron is converted to BF4~, extracted as a colored complex with methylene blue into dichloroethane, and measured spectrophotometrically at 660 ηιμ. Responsive concentration range is 0.2 to 2 5 y of boron. LASZLO PASZTOR and J. D. BODE, Jones & Laughlin Steel Corp., Pittsburgh 3 0 , Pa., and QUINTUS FERNANDO, University of Pittsburgh, Pittsburgh 1 3, Pa. Anal. Chem. 3 2 , 2 7 7 ( 1 9 6 0 )
Rapid Decomposition and Analysis Procedure for Microdetermination of Chlorine Compounds in Petroleum Fractions
A new decomposition apparatus which converts organ ically bound chlorine to chloride is combined with a sensitive precision null-point potentiometric method for determining chloride. The procedure provides a rapid determination of trace quantities of chlorine in petroleum fractions, insecticide extracts, or similar samples. Total analysis time is less than 10 minutes. H. V. MALMSTADT and J. D. WINEFORDNER, University of Illinois, Urbana, III. Anal. Chem. 3 2 , 2 8 1 ( 1 9 6 0 )
Volumetric Determination of Some Organophosphorus Halidates and Pyroester Compounds Using a Peroxide Reagent
A titrimetric macromethod is developed for determining organophosphorus halidates and pyroesters. The sam ple is reacted with alkaline peroxide and acidified and po tassium iodide is added. The liberated iodine is titrated with sodium thiosulfate and calculated as per cent organo phosphorus halide or pyroester. SAMUEL SASS, IRWIN MASTER, P. M. DAVIS, and NATHAN BEITSCH, Chemical W a r f a r e Laboratories, Army Chemical Center, M d . Anal. Chem. 3 2 , 2 8 5 ( 1 9 6 0 )
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