AC
BRIEFS Highlights of the scientific and technical articles in this issue
Determination of Radioactive Sulfur in Biological Materials
Determination of Hydrocarbon Oxidation Products. Reverse Isotope Dilution Analysis
A method for determining radioactive sulfur-3 5 in biological materials uses oxidation of the sample to magnesium sulfate which is dissolved in glycerol and diluted with ethyl alcohol and jV,AT-dimethylformamide. Phosphors containing toluene are added and the sample counted in a liquid scintillation counter.
Reverse isotope dilution analysis is employed to de termine the products from the radiation-induced oxida tion of propane over zinc oxide. Individual members of a homologous series are determined without inter ference by using recrystallization of a derivative as the purification method. The procedure saves time and is applicable for very small amounts of component for analysis.
HENRY JEFFAY, F. O . O L U B A J O , a n d W . R. JEWELL, University of Illinois, C h i c a g o , III. A n a l . Chem. 3 2 , 3 0 6 ( 1 9 6 0 )
W . H. C L I N G M A N , Jr., a n d Η. Η. Η Α Μ Μ Ε Ν , American O i l Co., Texas City, Tex. A n a l . Chem. 3 2 , 3 2 3 ( 1 9 6 0 )
The Absolute Assay of Sulfur-35 Counting
by Internal Gas
An interna! gas counting method is described for de termining the absolute disintegration rate of sulfur-35. Sulfur is converted to sulfur dioxide by ignition of barium sulfate with red phosphorus in an atmosphere of oxygen. The sulfur dioxide is mixed with methane and counted. W . F. MERRITT a n d R. C. H A W K I N G S , Atomic Energy o f C a n a d a , Ltd., Chalk River, O n t a r i o , C a n a d a A n a l . Chem. 3 2 , 3 0 8 ( 1 9 6 0 )
The Absolute Counting of Sulfur-35
A comparison study is made between several techniques used to determine the absolute disintegration rate of sulfur-3 5 solutions. The methods are differential gas counting as sulfur dioxide, 4τβ counting, and a tracer method. The techniques are altered to minimize the self-absorption effects considered to be the cause of the discrepancies in results. J. S. MERRITT, J. G . V. TAYLOR, W . F. MERRITT, a n d P. J. C A M P I O N , Atomic Energy o f C a n a d a , Ltd., Chalk River, O n t a r i o , C a n a d a A n a l . Chem. 3 2 , 3 1 0 ( 1 9 6 0 )
Determination of Oxides in Fluoride Salts by HighTemperature Fluorination with Potassium Bromotetrafluoride
The oxygen content of fluoride salts of yttrium, beryllium, zirconium, and magnesium is determined by high-tem perature fluorination. The sample is reacted with bromotetrafiuoride for 2 hours at 450° C. and the lib erated oxygen is measured tensimetrically. Accurate range of measurement is from 0.2 to 10 mg. of oxygen. GERALD GOLDBERG, A. S. MEYER, Jr., and J. C. WHITE, O a k Ridge n a t i o n a l L a b o r a t o r y , O a k Ridge, Tenn. A n a l . Chem. 3 2 , 3 1 4 (1960S
instrumental Neutron Activation Analysis
Radioisotopes of more than 2 5 elements are analyzed by an instrumental neutron activation system. The pro cedure consists solely of neutron activation followed by x-ray spectrometry. The method i; as accurate and sensitive as chemical and spectroscopic methods and is much faster, involving about 10 minutes per sample. V. P. G U I N N a n d C. D. W A G N E R , Shell Development Co., Emeryville Calif. Ana!. Chem. 3 ? 3 1 7 ( I 9 6 0 )
Electrodeposition Concentrations
of
Actinide
Elements at
Tracer
Trace concentrations of actinide elements are recovered from solution by electrodeposition. The elements are deposited on platinum disks from an electrolyte of am monium chloride-hydrochloric acid. The disks are removed from solution, washed with ethyl alcohol, and flamed. Determination of the elemental deposit is done by counting in a scintillation counter. R. F. MITCHELL, T r a c e r l a b , Inc., Richmond 3, Calif. A n a l . Chem. 3 2 , 3 2 6 ( 1 9 6 0 )
Separation of Magnesium from Sodium and Potassium. A Tracer Study
Sodium-24 and potassium-42 contamination of magnesium-28 is removed by precipitation of magnesium with 8-quinolinol. The procedure is more selective and complete than the precipitation procedures, yielding less than 1 gamma sodium coprecipitate per 69 milligram magnesium from solution containing from 0.4 to 4000 mg. of sodium. A. H. A. HEYN, Boston University, Boston, Mass., a n d H. L. FINSTON, Brookhaven National L a b o r a t o r y , U p t o n , L. Ι., Ν. Υ, A n a l . Chem. 3 2 , 3 2 8 ( 1 9 6 0 !
Rapid Method for Semiquantitative Determination of Volatile Aldehydes, Ketones, and Acids. Flash Exchange Gas Chromatography
A flash exchange gas chromatography technique is used for the semiquantitative determination of volatile alde hydes, ketones, and acids in vegetables. The derivatives of volatile compounds are heated with reagents in a capillary tube and the products volatilized directly into a gas chromatography unit. The technique is applicable to determination of flavor components of vegetables. J. W . RALLS, W e s t e r n Regional Research L a b o r a t o r y , A l b a n y 1 0 , Calif A n a l . Chem. 3 2 , 3 3 2 ( 1 9 6 0 )
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BRIEFS Gas Chromatographic Analysis of Oleflnic Naphthas in the Three- to Six-Carbon Range. With the A i d of a Subtraction Technique Individual components in olefinic naphthas are analyzed by a new gas c h r o m a t o g r a p h i c technique. T h e method is based on the use of successive runs in the presence and absence of olefins. Separate runs are made with and without an absorber which removes olefins from the solution. W i d e variations of three to six carbon com p o n e n t s are found in typical olefinic naphthas. R. L. MARTIN, S t a n d a r d O i l Co. (Indiana), W h i t i n g , Ind. Anal. Chem. 3 2 , 3 3 6 ( 1 9 6 0 )
Viscosity Measurement. The Kinetic Energy Correc tion and a N e w Viscometer A new improved viscometer is described which has a negligible kinetic energy correction over a viscosity range of 0.4 to 20,000 centistokes. It involves a simple correlation based o n the fact that the kinetic energy coefficient varies with Reynolds number. Precision is excellent for kinematic dilution and internal viscosity work. M. R. C A N N O N , The Pennsylvania State University, University Park, Pa., a n d R. E. M A N N I N G a n d J. D. BELL, Cannon Instrument Co., State College, Pa. A n a l . Chem. 3 2 , 3 5 5 ( 1 9 6 0 )
Informal Gas Chromatography Symposium T h e author offers a concise review of the informal discussion on gas c h r o m a t o g r a p h y which t o o k place under sponsorship of the Division of Analytical Chem istry at the national meeting of the American Chemical Society in Atlantic City last fall. W . W . BRANDT, Purdue University, L a f a y e t t e , Ind. A n a l . Chem. 3 2 , 3 3 9 ( 1 9 6 0 )
Theoretical Plates in Gas Chromatography. Effects of Distribution Ratio, Viscosity, and Amount of Liquid Phase
Polarographic Determination of Styrene Monomer in Polyester Resins T h e styrene m o n o m e r content of polyester resins is de termined by p o l a r o g r a p h i c analysis. T h e sample is dissolved in ethyl alcohol and p o l a r o g r a p h e d in tetrabutylammonium chloride. N o interference is encount ered from phthalate, fumarate, or maleate esters. W . M . AYRES and G . C. WHITNACK, U. S. N a v a l O r d n a n c e Test Station, China Lake, Calif. Anal. Chem. 3 2 , 3 5 8 ( 1 9 6 0 )
An evaluation study is made for three variables in the van Deemter, Zuiderweg, and K l i n k e n b e r g equation employed in gas chromatography. T h e variables are distribution ratio, film thickness, and diffusion. If one o r two of these variables is adjusted to make the equation factor C very small, the effect of the r e m a i n i n g variables appears to be nonexistent. J. J. DUFFIELD a n d L. B. ROGERS, Massachusetts Institute of Technology, C a m b r i d g e 3 9 , Mass. A n a l . Chem. 3 2 , 3 4 0 ( 1 9 6 0 )
Response of Thermal-Conductivity Chromatography
Cells
in
Gas
T h e performance of thermal-conductivity cells used in gas chromatography is investigated under theoretical and experimental conditions. T h e cell response is measured for a series of binary gas mixtures under a variety of temperatures of the cell and sensing element. An equation for response is derived employing a cell factor and a thermal-conductivity factor.
Determination of Traces of O x y g e n in Sodium Metal by Infrared Spectrophotometry Infrared spectrophotometry is used for the quantitative determination of small amounts of oxygen in sodium metal. Following a Wurtz reaction the pressed disk technique is applied to the sample. Absorbance band used is 11.38 microns H. J. deBRUIN, Australian Atomic Energy Commission, Lucas Heights, New South W a l e s , Australia A n a l . Chem. 3 2 , 3 6 0 ( 1 9 6 0 )
I . J. SCHMAUCH a n d R. A. DINERSTEIN, S t a n d a r d O i l Co. (Indiana), W h i t i n g , Ind. A n a l . Chem. 3 2 , 3 4 3 ( 1 9 6 0 )
Polarographic Characteristics and A m m o n i a
of
Ammonium
Ion
A systematic investigation is undertaken to determine the p o l a r o g r a p h i c characteristics of ammonium ion and also the electrode reaction at the d r o p p i n g mercury elec trode. P o l a r o g r a m s are obtained in 0.1 Λί tetramethylammonium iodide and for hydroxide solutions in the p H region between 4 and 13. In the acid region the -wave is irreversible, but in basic solution a reversible 1-elect r o n i c reduction is observed. C. J. N Y M A N , J. L. RAGLE, a n d P. F. LINDE, Washington State Uni versity, Pullman, W a s h . A n a i . Chem. 3 2 , 3 5 2 ( I 9 6 0 )
Separation of Cadmium from Uranium, Cobalt, Nickel, Manganese, Zinc, Copper, Titanium, and Other Elements by Cation Exchange Chroma tography A cation exchange c h r o m a t o g r a p h i c p r o c e d u r e is de veloped for the separation of cadmium from uranium, cobalt, nickel, manganese, zinc, copper, and titanium. U s i n g AG 50W-X8 exchange resin, cadmium is eluted with 0.5JV hydrochloric acid. Stannic tin indicates a response similar to cadmium and may be quantitatively separated from cation solutions with the same technique. F. W . E. STRELOW, South A f r i c a n Council for Scientific a n d Industrial Research, Pretoria, South Africa A n a l . Chem. 3 2 , 3 6 3 ( 1 9 6 0 )
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BRIEFS Infrared Spectroscopy of Surface Coatings in Reflected Light
Colorimetric Identification Phenolic Antioxidants
Organic surface coatings on metal surfaces are quali tatively and semiquantitatively analyzed by infrared spectroscopy. The infrared light passes through the coating, is reflected from the metal substrate and passes through the coating again, then to the spectrophotom eter. Good spectra from coatings of 0.1 to 0.5 mil thickness are obtained.
and
Estimation
of
A spectrophotometric method is devised for the qualita tive identification and quantitative estimation of phenolic antioxidants. The antioxidant is extracted with alcohol and coupled with />-nitroaniline giving a positive identification. Concentration is determined by spectro photometric analysis between 700 and 400 ταμ. C. L. HILTON, U. S. Rubber Co., W a y n e , N. J.
HANS DANNENBERG, J. W . FORBES, and A. C. JONES, Shell D e v e l o p ment Co., Emeryville, Calif. A n a l . Chem. 3 2 , 3 6 5 ( 1 9 6 0 )
Automatic Recording of Derivative Ultraviolet Spectra. Application in Steroid Structure Deter mination
A simple, inexpensive attachment for the Cary Model II recording spectrophotometer permits direct recording of the first derivative of an ultraviolet spectrum. The technique distinguishes between alpha and beta epimers of ketosteroids as well as location of the position of substitution.
A n a l . Chem. 3 2 , 3 8 3 ( 1 9 6 0 )
A Continuous Gas Titration A n a l y z e r for Fluorine
A continuous automatic fluorine analyzer is described for monitoring and control of complex gas systems. It operates on the basis of the pneumatic detection of the reduction in molar flow as fluorine reacts with sulfur dioxide. Other gases may be analyzed by changing the reagent and reactor conditions. C. W . WEBER, Union C a r b i d e Nuclear Co., O a k Ridge, Tenn. A n a l . Chem. 3 2 , 3 8 7 ( 1 9 6 0 )
E. C. O L S O N a n d C. D. A L W A Y , The Upjohn Co., K a l a m a z o o , Mich. A n a l . Chem. 3 2 , 3 7 0 ( 1 9 6 0 )
Rapid Determination of Phosphorus in Spectrographic and Colorimetric Methods
Gasoline.
The phosphorus content of gasoline is determined by spectrographic and colorimetric procedures. The spec trographic method is the more rapid and has a range between 5 and 7 5 mg. phosphorus per liter, while the colorimetric method indicates a range of 5 to 50 mg. Neither method is affected by the presence of additives commonly found in gasolines.
Gravimetric Determination of Bismuth with Dimethylglyoxime
A gravimetric method is based on the quantitative pre cipitation of bismuth with dimethylglyoxime from solutions containing a variety of interfering ions. The effects of the adverse ions are controlled by masking with EDTA and potassium cyanide. From 50 to 500 mg. of bismuth may be determined. P. F. LOTT a n d R. K. VITEK, University of Missouri, Rolla, M o .
M. E. GRIFFING, C. T. LEACOCK, W . R. O'NEILL, A. L. ROZEK, and G . W . SMITH, Ethyl Corp., Detroit, Mich. Anal. Chem. 3 2 , 3 7 4 ( 1 9 6 0 )
Thiomalic Acid as Reagent for Zirconium
Zirconium is quantitatively precipitated from acid solu tion with thiomalic acid. Mercury and thorium inter ferences are easily eliminated in procedure. However, bismuth must be separated prior to the precipitation step. The precipitate composition is zirconyl thiomalate.
A n a l . Chem. 3 2 , 3 9 1 ( I 9 6 0 )
Determination of Glucose in Blood Serum by a NewRapid and Specific Automatic System
Catalytic oxidation of glucose is carried out in a coupled enzyme reaction to form a colored reaction product. Automatic results for glucose in standards and blood serum show good proportionality and a co efficient of variation of about 2%.
S. B. SANT, Mount Holyoke C o l l e g e , South H a d l e > , Mass., and B. R. SANT, Louisiana State University, Baton Rouge, La.
H. V. MALMSTADT a n d G . P. HICKS, University of Illinois, U r b a n a , III.
A n a l . Chem. 3 2 , 3 7 9 ( I 9 6 0 )
A n a l . Chem. 3 2 , 3 9 4 ( I 9 6 0 ;
Colorimetric Determination of Small Amounts of Nitroprusside and A q u o - and Ammonopentacyanoferrates(ll)
Small quantities of nitroprusside and aquo- and ammonopentacyanoferrates are determined colorimetrically. The aquo- and ammonopentacyanoferrates are complexed as azides and their absorbances measured at 560 πχμ. Nitroprusside is reacted with isophorone and the com plex color intensity measured at 495 πιμ. BRUNO JASELSKIS Ann A r b o r , Mich.
und
J. C. EDWARDS, University
of
Michigan,
A n a l . Chem. 3 2 , 3 8 !
(I960)
Determination and Reactions of Some O x y - A n i o n s in Fused Chlorides and Nitrates
Acidic
Acidic oxy-anions in fused salts are determined by reacting the salt with excess sodium carbonate and measuring the number of moles of carbon dioxide evolved. The procedure accurately determines dichromate, metaphosphate, and metavanadate in lithium chlo ride-potassium chloride melts. J. D. V A N N O R M A N a n d R. A. OSTERYOUNG, Rensselaer Polytechnic Institute, Troy. Ν. Υ. A n a l . Chem. 3 2 , 3 9 8 ( 1 9 6 0 )
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BRIEFS Extraction of Thorium with Thenoyltrifluoroacetone. Effect of Acetic Acid Acetic acid increases the extraction of thorium through the formation of thorium thenoyltrifluoroacetone-acetic acid complex. T h e selection of the organic solvent depends upon the solubility of the metal chelate and the effects of the buffer system o n the miscibility of the phases. Carbon tetrachloride and hexone are found to be satisfactory solvents. GERALD GOLDSTEIN, OSCAR MENIS, and D. L. M A N N I N G , Ridge National L a b o r a t o r y , O a k Ridge, Tenn.
A Simple Rapid Vapor Pressure Micromethod A rapid vapor pressure m i c r o m e t h o d is developed, based o n the change of position of a mercury plug acting as a free piston in a capillary tube. T h e unit in operation will withstand temperatures up to 400° C. and pressures to 20 atmospheres. C. Y. SHEN a n d R. A. HERRMANN, Monsanto Chemical Co., St. Louis, M o . A n a l . Chem. 3 2 , 4 1 8 ( 1 9 6 0 )
Oak
A n a l . Chem. 3 2 , 4 0 0 ( 1 9 6 0 )
Polarographic Behavior of Aryl Sulfones and Sulfoxides T h e products in the electroreduction of sulfones and sulfoxides are estimated by p o l a r o g r a p h i c analysis. Phenyl methyl sulfone, phenyl sulfone, and the corres p o n d i n g sulfoxides are studied at a d r o p p i n g mercury electrode and a mercury p o o l electrode. T h e product of an aryl sulfoxide is the c o r r e s p o n d i n g thioether. R. C. BOWERS a n d H. D. RUSSELL, Northwestern University, Evanston, III. A n a l . Chem. 3 2 , 4 0 5 ( 1 9 6 0 )
Vapor Phase Separation of Methyl- or Ethylmercury Compounds and Metallic Mercury A method is described for the capture and determination of methyl- o r ethylmercury c o m p o u n d s in the r a n g e of 10 7 or more per 1000 liters of air in the presence of metallic mercury vapor. Quantitative separation is obtained w h e r e a single organic mercury vapor coexists with metallic mercury vapor. YOSH KIMURA and V. L. MILLER, Washington State University, Puyallup, Wash. A n a l . Chem. 3 2 , 4 2 0 ( 1 9 6 0 )
Relative Acidities of Substituted Phenols in Pyridine a n d Water T h e behavior of phenolic c o m p o u n d s in pyridine and water is evaluated with reference to the acidity relationship of the phenols between the two solvents. T h e acidity of hydroxy aromatic c o m p o u n d s is increased relative to carboxylic acids w h e n titrated with pyridine. T h e study also includes noncarboxylic, n o n p h e n o l i c organic acids. C. A. STREULI, American C y a n a m i d Co., S t a m f o r d , Conn. A n a l . Chem. 3 2 , 4 0 7 ( 1 9 6 0 )
Evaluation of Standard Model D Keston Polarimetric Attachment for the Beckman DU Spectrophotometer T h e attachment was tested to evaluate its use for measuring optical rotatory dispersion, particularly in the vicinity of an optically active absorption band. T h e unit was found useful for measurements in the normal part of a rotatory dispersion curve, especially for highly colored solutions.
Desulfurization as a Method of Identifying Sulfur Compounds A simple, direct m i c r o m e t h o d for identifying organic sulfur c o m p o u n d s employs a technique of desulfurization. T h e sample is passed over a catalyst at high temperature where the sulfur is removed. T h e hydrocarbon produced is analyzed by gas-liquid chromatography o r by mass o r infrared spectroscopy. T h e lower limits of sample volume are well under 0.0002 ml. C. J. T H O M P S O N , H. J. COLEMAN, C. C. W A R D , and H. T. RALL, U. S. Department of the Interior, Bartlesville, O k l a . A n a l . Chem. 3 2 , 4 2 4 ( 1 9 6 0 )
K. G . POULSEN, University o f C a l i f o r n i a , Los Angeles, Calif. A n a l . Chem. 3 2 , 4 1 0 ( 1 9 6 0 )
Determination of Sulfur in Petroleum Products by Hydrogénation
Determination of Cystine by on the lodine-Azide Reaction
Its Catalytic
Effect
Sulfur is converted to hydrogen sulfide and absorbed in dilute sodium hydroxide solution. T h i s is followed by amperometric titration with standard mercuric chloride if the sulfur concentration is above 0 . 1 % . Below 0.1 % the methylene blue method is used.
A simple and accurate catalytic method is described for determining cystine and cysteine in protein hydrolyzates. T h e method is based o n the catalytic effect of divalent sulfur c o m p o u n d s o n a reaction between iodine and azide. O t h e r divalent sulfur c o m p o u n d s are applicable in this procedure.
E. C. SCHLUTER, Jr., E. P. PARRY, and GEORGE MATSUYAMA, Union O i l Co. o f C a l i f o r n i a , Brea, Calif. A n a l . Chem. 3 2 , 4 1 3 ( 1 9 6 0 )
R. D. STRICKLAND, P. A. M A C K , and W . A. CHILDS, Veterans Administration Hospital, A l b u q u e r q u e , Ν. Μ . Anal. Chem. 3 2 , 4 3 0 ( 1 9 6 0 )
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