AC BRIEFS

detection system using multiplier phototubes adapted to an f/6.3 spectrograph, permits the development .... DANIEL P. LUCERO, Electro-Analytical Trans...
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AC BRIEFS Q-Switched Ruby Laser for Emission Microspectroscopic Elemental Analysis A highly stable Q-switched ruby laser combined with a detection system using multiplier phototubes adapted to an f/6.3 spectrograph, permits the development and eval­ uation of laser-induced spectroscopy. N O R M A N A . PEPPERS, EARL J . SCRIBNER, L L O Y D E. ALTERT O N , and R I C H A R D C . H O N E Y , Stanford Research Institute, M e n l o Park, C a l i f . 94025 and, E D W I N S. BEATRICE. I N G E B O R G H A R D I N G - B A R L O W , ROBERT C . R O S A N , and D A V I D G L I C K , Stanford University School of M e d i c i n e , Stanford, C a l i f . 9 4 3 0 4

HIGHLIGHTS TECHNICAL

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Liquid-Liquid Extraction of Nickel with LongChain Amines from Aqueous and Nonaqueous Halide Media With correct conditions, high distribution ratios for nickel can be readily achieved, particularly if the extractions are made from nonaqueous, methanolic halide solutions. T. M . F L O R E N C E and Y V O N N E J . F A R R A R , A n a l y t i c a l C h e m ­ istry Section, Australian A t o m i c Energy Commission, Lucas Heights, N . S. W . , Australia A n a l . C h e m . 4 0 , 1200 ( 1 9 6 8 )

A n a l . C h e m . 4 0 , 1178 ( 1 9 6 8 )

Determination of Carbon-14 in the Methoxyl Group of Organic Compounds

Vapor Pressure Detector for Liquid Elution Chromatography. Its Potential Use in Shale-Oil Characterization

A compound which contains the methoxyl group is refluxed with Kirsten's reagent and methyl iodide generated is introduced into an absorption tube containing silica gel. T h e radioactivity of methyl iodide—"C is then measured.

The observed detection limit was 0.8 X 10"° mole kg" 1 with cyclohexane solvent. T h e effective sensing volume of the detector was 90 μϊ at a flow rate of 2.0 m l / h o u r decreasing at lower flow rates.

M I T S U O C H U B A C H I , E I K O K A W A N O , and M A S A Y U K I H A M A D A , Radiation C e n t e r of Osaka Prefecture, Sakai, Osaka, J a ­ pan

R. E. P O U L S O N and H . B. J E N S E N , U . S. Department of the Interior, Bureau of Mines, Laramie Petroleum Research Center, Laramie, W y o . 8 2 0 7 0

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An Analytical Function f o r Describing Gamma-Ray Pulse-Height Distributions in N a l ( T I ) Scintillators Digital spectra are treated by computer which by use of a combination of residual least squares and interaction methods selects the optimum parameters for each case based on radioactive statistical criteria.

Theoretical-Slope Method of End Point Detection The rapid and precise theoretical-slope method of end point detection is used for titration systems where the ratio of conditional stability constants is less than 100. J . R. D E A N and W . E. H A R R I S , University of A l b e r t a , Edmonton, Alberta, Canada A n a l . C h e m . 4 0 , 1213 ( 1 9 6 8 )

B. R. K O W A L S K I and T. L. I S E N H O U R , Department of Chemistry, University of W a s h i n g t o n , Seattle, W a s h . 98105 A n a l . C h e m . 4 0 , 1186 ( 1 9 6 8 )

Study of the Chemical Etching Procedure Used t o Remove Surface Oxygen Contamination in Charged Particle Activation Analysis Errors arising from fluorine-18 activity adsorbed onto the sample matrix during a chemical etching procedure used to remove surface contamination is the subject of this re­ port. H A R R Y L. R O O K , E M I L E A . S C H W E I K E R T , a n d R I C H A R D E. W A I N E R D I , A c t i v a t i o n Analysis Research Laboratory, Texas A & M University, C o l l e g e Station, Tex. 77843

Mass Spectrometer-Computer System Particularly Suited for Gas Chromatography of Complex Mixtures The basic feature of this on-line system is the continuous scanning and recording of mass spectra at four-second in­ tervals, thus eliminating the need to decide constantly during an experiment whether or not to record a given spectrum and the risk of not scanning a spectrum which later turns out to be important. R O N A L D A . HITES and Κ. Β Ι Ε Μ Α Ν Ν , Department of Chemistry, Massachusetts Institute of Technology, C a m b r i d g e , Mass. 0 2 1 3 9 A n a l . C h e m . 4 0 , 1217 ( 1 9 6 8 )

A n a l . C h e m . 4 0 , 1194 ( 1 9 6 8 )

Gas Chromatograph-Combustion-Continuous Counting System for Analysis of Microgram Amounts of Radioactive Metabolites T h e mass detector is sensitive to less than 0.1 jug and shows a linear response over a 2000-fold concentration range. 200 to 100,000 dpm of " C can be detected in a given peak.

Theoretical Aspects of an Acoustical Detector Possessing Hydrogen Specificity T h e detector ceiver systems mixture or its low and above

consists of two ultrasonic transmitter-re­ that measure the acoustic velocity of a gas absorption characteristics, and operate b e ­ the relaxation frequency.

R. O . M A R T I N , Department o f Biochemistry, University o f Sas­ katchewan, Saskatoon, Sask., C a n a d a

D A N I E L P. L U C E R O , Electro-Analytical Transducer Corp., Fullerton, C a l i f , and, ALBERT C . K R U P N I C K , G e o r g e C . Marshall Space Flight Center, Huntsville, A l a .

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AC BRIEFS Determination of Brompheniramine in Blood and Urine by Gas-Liquid Chromatography

Examination of the Hammett Equation for Gas-Liquid Chromatography The H a m m e t t equation is related to the relative activity coefficients (phenol :substituted phenol) at infinite dilution. Prediction of the types of liquid phases necessary for optimum resolution is possible.

The procedure involves the separation of brompheniramine by extraction and partition chromatography followed by oxidation to p-bromophenyl-2-pyridyl ketone. The ketone is then determined by GLC.

BARRY L. K A R G E R , Y U S E F E L M E H R I K , and ROBERT L. STERN, Department of Chemistry, Northeastern University, Boston, Mass. 02115

ROBERT B. BRUCE, J E F F E R S O N E. PITTS, and F R A N K L I N M . P I N C H B E C K , A . H . Robins C o . , Inc., Research Laboratories, Richmond, V a .

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A n a l . C h e m . 4 0 , 1246 ( 1 9 6 8 )

Determination of Nanogram Quantities of Chlorpromazine and Some of Its Metabolites in Plasma Using Gas-Liquid Chromatography with an Electron Capture Detector

Detection of Subnanogram Quantities of Hexachlorophene by Electron Capture Gas Chromatography T h e mean deviation of five 0.400-mg depositions estimated by E C - G C is 0.0086 mg, and the standard deviation is 0.0104 mg. Error is less than 3 % at this level. PETER J . P O R C A R O A N D PETER S H U B I A K , ment, Givaudan C o r p . , C l i f t o n , N . J . 07014

Research

Depart-

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Concentrations as low as 10 n g / m l of chlorpromazine, its sulfoxide, and its demethylated analogs can be determined. Four compounds in the plasma of psychiatric patients have been identified. STEPHEN H . C U R R Y , Laboratory of Chemical Pharmacology, N a tional H e a r t Institute, N a t i o n a l Institutes of H e a l t h , Bethesda, M d . 20014 A n a l . C h e m . 4 0 , 1251 ( 1 9 6 8 )

Interaction Second Virial Coefficients of Some Hydrocarbon-Hydrocarbon Gas Mixtures from Gas-Liquid Chromatography

New Substrates f o r the Fluorometric Determination of Oxidative Enzymes

Results for B J 2 of 11 gas mixtures are presented: w-pentane, iso-pentane, «-hexane, 2-methylpentane, 2,2-dimethylbutane in methane at two temperatures, and npentane in ethane at one temperature. Precision is about ± 2 5 cmVmole.

From a survey of 25 indicator substrates for the fluorometric determination of oxidative enzymes, p-hydroxy.phenylacctic acid is judged to be the best substrate. A precision of 1.5% is reported for 0.3-30 ,ug per ml of several enzymes.

R. L. PECSOK and M . L. W I N D S O R , Department of Chemistry, University of C a l i f o r n i a , Los Angeles, C a l i f . 9 0 0 2 4

G E O R G E G . G U I L B A U L T , P A U L J . B R I G N A C , JR., and M A R K J U N E A U , Department of Chemistry, Louisiana State University in N e w Orleans, Lalcefront Campus, N e w Orleans, La. 70122

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Gas Chromatographic Analysis of Insensitive Pesticides as Their Halomethyldimethylsilyl Derivatives The method is rapid and versatile permitting detection of pesticide and herbicide compounds in the range of 1 to 100 nanograms. T h e procedure is applied to an analysis of soil. C . A . B A C H E , L. E. St. J O H N , JR., and D. J . LISK, Pesticide Residue Laboratory, Cornell University, Ithaca, N . Y . I 4 8 5 0 A n a l . C h e m . 4 0 , 1241 ( 1 9 6 8 )

Use of M e t a l Ion Catalysis in Detection and Determination of Microamounts of Complexing Agents. Autoxidation of L-Ascorbic Acid as an "Indicator" Reaction Trace amounts of cysteine, 2-aminoethanethiol, salicylic acid, E D T A , 1,10-phenanthroline, and ethylenediamine have been determined by this method. H O R A C I O A . M O T T O L A , M A R T H A S. H A R O , and H E N R Y FREISER, Department of Chemistry, University of Arizona, Tucson, Ariz. 85721 A n a l . C h e m . 4 0 , 1263 ( 1 9 6 8 )

Determination of Propoxyphene in Human Plasma by Gas Chromatography T h e method is based on solvent extraction at neutral or near neutral p H values followed by purification and concentration of the extract, which is then analyzed by GC using a short column with a liquid phase of silicone gum rubber.

Use of Metal Ion Catalysis in Detection and Determination of Microamounts of Complexing Agents. Catalimetric Titration of Cyanide Ion Low concentrations of cyanide ions (10"W level) have been determined. T h e end point is reached when 1 mole of Cu has reacted with 2 moles of cyanide ion. Effects of titration parameters and interferences are discussed.

ROBERT L. W O L E N and C H A R L E S M . GRUBER, JR., Lilly Laboratory f o r C l i n i c a l Research, M a r i o n County G e n e r a l H o s p i t a l , Indianapolis, Ind. 4 6 2 0 2

H O R A C I O A . M O T T O L A and H E N R Y FREISER, D e p a r t m e n t of Chemistry, University of Arizona, Tucson, Ariz. 85721

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AC BRIEFS Polarographic Reduction of Diphenylthallium( I I I ) Cation in Aqueous Solution

Spectrophotometry and Spectrofluorometric Study of Flavonol-Aluminum Chelates in Absolute Ethyl Alcohol Spectrophotoraetric evidence is presented for the existence of chelate species containing two aluminum ions per flavonol and one aluminum ion per flavonol. FRED L. U R B A C H and A N D R E W T I M N I C K , Department o f Chemistry, M i c h i g a n State University, East Lansing, M i c h . 48823 A n a l . C h e m . 4 0 , 1269 ( 1 9 6 8 )

Spectrophotometric Determination of Aliphatic Amines by Acylation with Cinnamic Anhydride irans-Cinnamic anhydride is introduced as an acylating agent for amines. T h e powerful light absorption by the irans-cinnamoyl group makes the method quite sensitive. W E N - H A I H O N G A N D K E N N E T H A . C O N N O R S , School Pharmacy, University of Wisconsin, Madison, W i s . 53706

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The mechanism of the polarographic reduction of the diphenylthallium(III) cation is studied, and decay schemes for the transient organothallium species formed at the D M E are proposed. J O S E P H S. D i G R E G O R I O and M I C H A E L D. M O R R I S , Depart­ ment of Chemistry, The Pennsylvania State University, University Parle, Pa. 16802 A n a l . C h e m . 4 0 , 1286 ( 1 9 6 8 )

Potentiometric Determination of Boron as Tetrafluoroborate A liquid ion exchange membrane electrode is used for measuring tetrafluoroborate concentrations down to 10~"°M. Interference from several anions is estimated, and the method is applied to the determination of boron in water samples. R. M . C A R L S O N , Department of Pomology, University of C a l i ­ fornia, Davis, C a l i f . 95616 and, J . L. PAUL, Department of En­ vironmental Horticulture, University o f C a l i f o r n i a , Davis, C a l i f . 95616 A n a l . C h e m . 4 0 , 1292 ( 1 9 6 8 )

Spectrophotometric Method for Hydrofluoric Acid in Stainless Steel Pickling Baths

Nitrogen and Oxygen Compound Types in Petroleum. A General Separation Scheme

Labora­

An integrated separation scheme, based on adsorption chromatography on alumina, silica, and charcoal, and ion exchange on cation and anion resins, is presented for the separation of nitrogen and oxygen compound types in petroleum.

A n a l . C h e m . 4 0 , 1276 ( 1 9 6 8 )

L. R. S N Y D E R and B. E. BUELL, Union O i l C o . of C a l i f o r n i a , Union Research C e n t e r , Brea, C a l i f .

The procedure utilizes the bleaching of the red-colored ferric acetylacetonate complex at 470 ηΐμ in a 0.1N HNO3 medium for the measurement of H F . J . P. M c K A V E N E Y , C r u c i b l e Steel C o m p a n y , tory, P. O . Box 9 8 8 , Pittsburgh, Pa. 15230

Research

A n a l . C h e m . 4 0 , 1295 ( 1 9 6 8 )

Nitrogen and Oxygen Compound Types in Petroleum. Total Analysis of a 700-850 °F Distillate from a California Crude Oil

Specific Colorimetric Reagents f o r the Determination of Palladium ( I I ) The optimum range for t h e effective colorimetric determi­ nation is 0.5 to 7.2 ppm. T h e sensitivity is 0.085 and 0.026 /xg of P d per sq cm for T P O and TPOO, respectively. K R I S H N A K. S A X E N A and A R U N K. DEY, C h e m i c a l Laboratories, 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 . 4 0 , 1280 ( 1 9 6 8 )

Petroleum fractions are analyzed by a combination of high resolution mass spectrometry, infrared and ultra­ violet spectrophotometry, elemental analysis, and acid and base titration. L. R. S N Y D E R , B. E. BUELL, and Η . Ε. H O W A R D , Union O i l C o . of C a l i f o r n i a , Union Research Center, Brea, C a l i f . A n a l . C h e m . 4 0 , 1303 ( 1 9 6 8 )

Nuclear Magnetic Resonance Chemical Shifts of Oxygenated Unsaturated Aliphatics

Determination of Impurities in Bromine by Infrared Spectrophotometric Methods Common impurities encountered in bromine can be de­ tected in concentrations below 1 μ& per ml. A method for determining chlorine in bromine b y infrared techniques is described.

Detailed correlations of chemical shift with structure for unsaturated oxygenated aliphatics are presented in chart form. T h e effects of substituent position and of conjuga­ tion on the chemical shifts are shown graphically.

Chemical

N U G E N T F. C H A M B E R L A I N , Esso Research & Engineering C o . , Baytown Research and Development Division, Box 4 2 5 5 , Baytown, Texas 7 7 5 2 0

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L Y N N H . H A H N and L O R E N E. P A U L I N G , M i c h i g a n C o r p . , 5 0 0 N o r t h Banltson, St. Louis, M i c h . 4 8 8 8 0

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AC BRIEFS Simultaneous Differential Thermal AnalysisThermogravimetric Analysis Technique to Characterize the Explosivity of Lead Azide A technique to differentiate between detonation and de­ composition of PbNe is described, based on the per cent weight, loss of the sample and t h e heat evolved in a deto­ nation. Mass and heating rate criteria for detonations are established. V . R. P A I V E R N E K E R and J . N . M A Y C O C K , Research Institute f o r A d v a n c e d Studies, M a r t i n M a r i e t t a C o r p . , 1450 South Rolling Road, Baltimore, M d . 21227

Spectrophotometric Determination of Nickel with 2-Amino-l-Cyclopentene-lDithiocarboxylic Acid T h e compound reacts with Ni (II) ion in aqueous solution to form a pink-red compound. T h e visual sensitivity was 20 ppb. Beer's law is obeyed between 0.5 to 5 p p m . M A S A T A K A Y O K O Y A M A and T A T S U O T A K E S H I M A , Depart­ ment of Chemistry, C h i b a University, Yayoi-cho, C h i b a C i t y , Japan A n a l . C h e m . 4 0 , 1344 ( 1 9 6 8 )

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Thin Film Thermocouples for Differential Thermal Analysis The problems for changes in heat transfer coefficient b e ­ tween sample and sensor are practically eliminated b y the low mass of the thermocouples, the small sample size, and other design features.

Electron Microprobe Analysis of N i c k e l - I r o n Cobalt Thin Film W i r e Memory Elements The method provides a rapid technique for the determina­ tion of the composition of trinary films and could be ex­ tended to the analysis of any micron or submicron sized sample.

W . H . K I N S , J R . , and C . T. C A M I L L I , Esso Research and Engi­ neering C o . , Linden, N . J . , and A . F. F I N D E I S , University of A l a ­ b a m a , University, A l a .

A . A . C H O D O S , Division of G e o l o g i c a l Sciences, C a l i f o r n i a In­ stitute of Technology, Pasadena, C a l i f . 91 109

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Quantitative Comparison of Powder Diffraction Patterns Automated photometry coupled with computerized pro­ cessing of digitized data permits the comparison of di­ verse powder diffraction patterns in a quantitative nonsubjective manner. L. K. FREVEL and C . E. A D A M S , C h e m i c a l Physics Research Lab­ oratory and C o m p u t a t i o n Research Laboratory, The Dow C h e m i c a l Co., Midland, Mich. A n a l . C h e m . 4 0 , 1335 ( 1 9 6 8 )

Spectrophotometric Determination of Pyrazolines and Some Acrylic Amides and Esters The method is based on the fact that pyrazolines are readily formed from the reaction of diazomethanc with many acrylic and related compounds, including acrylamide, to give intensely colored derivatives with certain aldehydes. A . R. M A T T O C K S , Toxicology Research Unit, M e d i c a l Research Council Laboratories, W o o d m a n s t e r n e Road, Carshalton, Surrey,

England A n a l . C h e m . 4 0 , 1347 ( 1 9 6 8 )

Notes Gas Chromatographic Bubble-Gas Analysis f o r Determination of Hydrazine Gel Decomposition Mechanism The principal decomposition reaction occurring with the hydrazine gel is determined to be 3N 2 H 4 = N 2 + 4 N H s because the primary decomposition product in all analyses is nitrogen, rather than equal amounts of nitrogen and hydrogen.

Determination of Stoichiometry of Vanadium and Titanium Oxides by 14-MeV Neutron Activation Vanadium monoxides and some mixtures of VO and T i O are analyzed by 14-MeV neutron activation in a wide composition range without interferences. C A R M I N E P E R S I A N I and J A M E S F. C O S G R O V E , The Bayside Laboratory, Research C e n t e r of G e n e r a l Telephone & Electronics Laboratories Inc., Bayside, Ν . Υ . A n a l . C h e m . 4 0 , 1350 ( 1 9 6 8 )

N . A . K I R S H E N and G . H . O L S E N , Poulter Laboratory for H i g h Pressure Research, Stanford Research Institute, M e n l o Park, C a l i f . A n a l . C h e m . 4 0 , 1341 ( 1 9 6 8 )

Electrochemical Generation of Fluoride Ion by Solid-State Transference Fluoride ion has been electrochemically generated for the first time by means of the solid-state transport of fluoride ions through a permselective membrane of europiumdoped lanthanum fluoride. R I C H A R D A . DURST, Division of A n a l y t i c a l Chemistry, Institute for M a t e r i a l s Research, N a t i o n a l Bureau of Standards, W a s h i n g ­ ton, D. C . 20234 and, J A M E S W . ROSS, J R . , O r i o n Research, Inc., C a m b r i d g e , Mass. 0 2 1 3 9

Determination of Parts-per-Million Quantities of Plutonium-236 in Plutonium-238 by Alpha Pulse Height Analysis Duplicate measurements made on seven samples with two different detector-analyzer-amplifier systems verified the reproducibility of the simple and rapid technique de­ scribed. M A R Y L O U C U R T I S , Monsanto Laboratory, Miamisburg, O h i o

Research

Corporation,

Mound

A n a l . C h e m . 4 0 , 1343 ( 1 9 6 8 ) A n a l . C h e m . 4 0 , 1352 ( 1 9 6 8 ) . Circle No. 70 on Readers' Service Card V O L . 4 0 , N O . 8 , JULY 1 9 6 8

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AC

Correlation of Aromatic Substituent Effects with Gas—Solid Chromatographic Retention

Spectrophotometric Determination of Cyanide Ion with tris(1,10-Phenanthroline)Iron(II)Triiodide Ion Association Reagent A useful, rapid method for the determination of small con­ centrations of free, uncomplexed cyanide ion in neutral solution in the absence of strong oxidizing or reducing agents is presented. J A C K L. LAMBERT and D A V I D J . M A N Z O , Department Chemistry, Kansas State University, M a n h a t t a n , Kan.

BRIEFS

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The gas chromatographic behavior of Na 2 SO t -deactivated porous silica beads has been investigated with salt-modi­ fied aluminas as absorbents. D A V I D J . B R O O K M A N and D O N A L D T. S A W Y E R , Department of Chemistry, University of California, Riverside, C a l i f . 92502 A n a l . C h e m . 4 0 , 1368 ( 1 9 6 8 )

A n a l . C h e m . 4 0 , 1354 ( 1 9 6 8 )

Resolution of Racemic Aspartic Acid, Tryptophan, Hydroxy and Sulfhydryl Amino Acids by Gas Chromatography The successful resolution of 0,N, or S-diTFA derivatives of serine, hydroxyproline, tyrosine, and cysteine as well as aspartic acid and tryptophan is reported; synthesis meth­ ods are also given.

Conversion of W a t e r to Carbon Dioxide with N.N'-Carbonyldiimidazole An improved mass spectrometric analysis of oxygen-18 has been developed and applied to the analysis of natural water and enriched water. J A M E S C . W A R F , J e t Propulsion Laboratory, California of Technology, Pasadena, C a l i f .

Institute

A n a l . C h e m . 4 0 , 1370 ( 1 9 6 8 ) G L E N N E. P O L L O C K and A . H . K A W A U C H I , Exobiology Divi­ sion, Ames Research Center, N A S A , M o f f e t t Field, C a l i f . 94035 A n a l . C h e m . 4 0 , 1356 ( 1 9 6 8 )

Gas Chromatographic Analysis of Tall Oil Fatty Alkyds f o r Monomer and Dimer Acid Content A G C method is described for the analysis of monomer and dimer fatty acids as their methyl esters which is rapid and convenient. T h e relative error for dimer acids is ap­ proximately ± ΙΟ'/c of the amounts present. R. A . L. P A Y L O R . R A Y M O N D F E I N L A N D , and N . H . C O N R O Y , American C y a n a m i d C o . and Arizona Chemical C o . , Stamford, Conn.

Separation of Chlorostyrenes and Ethylbenzene/Xylenes The separation of the isomeric monochlorostyrenes and ethylbenzene/xylenes using a column of Rentone-34 modi­ fied with bis-(phenoxyphenyl) ether (4P3E) is compared with separations obtained on other modified Bentone-34 columns. C H A R L E S F. RALEY and J A M E S W . K A U F M A N , Physical Re­ search Laboratory, The Dow Chemical C o . , M i d l a n d , M i c h . A n a l . C h e m . 4 0 , 1371 ( 1 9 6 8 )

A n a l . C h e m . 4 0 , 1358 ( 1 9 6 8 )

Comparison of Two Approximate Formulations of the Koutecky Function

Chronopotentiometric Study of the Oxidation of Iodide on Platinum Surfaces in Fused Sodium Nitrate-Potassium N i t r a t e Eutectic at 250 C

The present communication compares the Smith—McCord— Hung approximation to F ( a ) with that of Oldham and Parry and points out the advantages of each.

The present work supports and extends previous voltammctric studies and further characterizes the nature of this process.

K E I T H B. O L D H A M , Science Center of the North American Rockwell C o r p . , Thousand Oaks, C a l i f . 9 1 3 6 0 and, D O N A L D E. S M I T H , Department of Chemistry, Northwestern University, Evanston, I I I . 60201

R. B. F U L T O N and H . S. S W O F F O R D , JR., Department of C h e m ­ istry, University of Minnesota, Minneapolis, M i n n . 55455 A n a l . C h e m . 4 0 , 1373 ( 1 9 6 8 )

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Analysis of Saturated Aldehydes by Gas-Liquid Chromatography Using Methylolphthalimide f o r Regeneration of Their Girard-T Derivatives

Determination of Potassium lodate Sampled from Sodium Nitrate-Potassium Eutectic Melts a t 250 C by Coulometric Back-Titration in Aqueous Medium

Results indicate that the three-step procedure described is suitable for quantitative or highly semiquantitative de­ termination of saturated aldehydes up to Cu.

The method described has been applied to the determina­ tion of samples in the range of 24 ,itequiv to 68 ,u.equiv of potassium iodato with a relative error from 0.4 to 1.4%.

D O N A L D F. G A D B O I S , P A U L G . S C H E U R E R , and FREDERICK J . K I N G , U . S. Bureau of C o m m e r c i a l Fisheries, Gloucester, Mass. 01930

R. B. F U L T O N and H . S. S W O F F O R D , JR., Department of C h e m ­ istry, University of Minnesota, Minneapolis, M i n n . 55455

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Pyrolysis-Gas Chromatographic Determination of Organics in Aqueous Solutions

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Atomic Absorption Analysis of Ferrites

T h e method permits qualitative and quantitative charac­ terization of an aqueous sample. Samples as large as 0.25 cc can be used to detect dissolved organics at trace concentration levels.

Solutions containing the major constituents of the ferrites (LiNi, MnZn, and MnCu) in question were prepared from AA standards and analyzed with calibration plots. The results indicated an average accuracy of ± 3 % (relative) and the precision was about ± 1 % relative error.

I H O R LYSYJ and KURT H . N E L S O N , Research Division, Rocketdyne, 6633 C a n o g a Avenue, C a n o g a Park, C a l i f .

S O L O M O N L. LEVINE, Systems Development Division, Interna­ tional Business Machines C o r p . , Poughkeepsie, N . Y . I2603

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19 A

AC Analysis of National Bureau of Standards Potassium Dichromate, SRM-136b The types of trace contaminants that may be encountered in high purity potassium dichromate are determined, semiquantitative!}·, b y spark source mass spectrography. H A R R Y J . S V E C and ROBERT J . C O N Z E M I U S , Institute for A t o m i c Research and D e p a r t m e n t of Chemistry, Iowa State University, Ames, Iowa 5 0 0 1 0 A n a l . C h e m . 4 0 , 1379

A Sealed Polarographic Cell for Prolonged Studies of Reactions at the Dropping Mercury Electrode P A U L A R T H U R , D A V I D S. R U L I S O N , and K. DARRELL BERLIN, D e p a r t m e n t of Chemistry, Oklahoma State University, Stillwater, O k l a . 74074 A n a l . C h e m . 4 0 , 1389

(1968)

(1968)

Spectrophotometrie Determination of Methanol in Lactic Acid through the Hydrolysis and Vacuum Stripping of Methyl Lactate A precision (95% confidence limits) of ± 1 0 ppm was obtained at 71 ppm total methanol and ±10.4 ppm a t 95 ppm total methanol for two analyses, based on six replicates. ROBERT L. M A U T E , R O Y A L H . B E N S O N , and ERNEST TELLI, Monsanto C o . , Texas C i t y , Tex. 77591

BRIEFS

Determination of Complex Constants by Gas Chromatography H . S C H N E C K O , Organisch-chemisches Institut, Universitat M a i m , Germany A n a l . C h e m . 4 0 , 1391

(1968)

MAR-

A n a l . C h e m . 4 0 , 1380 ( 1 9 6 8 )

Determination of Oxygen and Nitrogen by Inert Gas Fusion with Impulse Heating

Correspondence Comments on the Linearized Current-Potential Characteristic

C . G . G O L D B R E K , S. P. TUREL, and C . J . R O D D E N , U. S. A t o m i c Energy Commission, N e w Brunswick Laboratory, New Brunswick, N . J . A n a l . C h e m . 4 0 , 1393

(1968)

S. K. R A N G A R A J A N , C e n t r a l Electrochemical Research Institute, Karaikudi-3, M a d r a s , India A n a l . C h e m . 4 0 , 1382

(1968)

Use of Light Frequency Modulation of Continuum Source in Atomic Absorption Photometry V R A T I S L A V S V O B O D A , Institute for Research, Production, Use of Isotopes, Pristavni 2 4 , Prague 7, Czechoslovakia A n a l . C h e m . 4 0 , 1384

and

Versatile Vapor Cell for Use in Infrared Spectrometry K. J . S T E R L I N G and R. J . H A I N E S , Research and Process Development, South A f r i c a n Iron and Steel Industrial C o r p . , Ltd., Pretoria, Republic of South A f r i c a A n a l . C h e m . 4 0 , 1395

(1968)

(1968)

Physical Significance of Parameters in Correlations of Rf Solvent Effects K E N N E T H A . C O N N O R S , School Wisconsin, Madison, W i s . 53706

of

Pharmacy,

University

A n a l . C h e m . 4 0 , 1386

of

(1968)

A Polytetrafluoroethylene Diffusion Cell N A N C Y W . A L C O C K , Kanematsu H o s p i t a l , Sydney, Australia

Memorial

Institute,

A n a l . C h e m . 4 0 , 1397

Sydney

(1968)

Aids for Analytical Chemists Determination of Free Magnesium by Combined Hydrogen Evolution and Gas Chromatography

Revolving Riffle for Subdividing Ground Magnesium Chips

V I R G I N I A D. H O G A N and F R A N C I S R. T A Y L O R , Laboratory, Picatinny Arsenal, Dover, N . J .

J A M E S R. M O N T G O M E R Y , M a l l i n c k r o d t Chemical Works, P. O . Box 5439, St. Louis, M o . 63160

Pyrotechnics

A n a l . C h e m . 4 0 , 1387

(1968)

A n a l . C h e m . 4 0 , 1399

V O L . 4 0 , N O . 8 , JULY 1 9 6 8

·

(1968)

21

A