HIGHLIGHTS OF T H E SCIENTIFIC A N D T E C H N I C A L A R T I C L E S IN THIS ISSUE
AC BRIEFS Evaluation of Correction Procedures Used in Electron Probe Microanalysis with Emphasis on Atomic Number Interval 13 to 33 Absorption, atomic number, and characteristic fluorescence correction procedures for a variety of alloys were evaluated for two electron probe ratio intervals, k > 0.1 and k < 0.1. Correction techniques investigated included those of Green, Duncumb and Shields, Tong, Thomas, Philibert, and Reed. D. R. B E A M A N , M e t a l l u r g i c a l Laboratory, M e t a l partment, The Dow C h e m i c a l C o . , M i d l a n d , M i c h .
Experimental Sensitivities in Neutron Activation and Gamma Spectrometry with a 150-kV Accelerator Photopeaks for main elements obtained with fast neutrons and the limits of detection for each photopeak have been tabulated. T h e potential limit of detection achievable for each photopeak has been calculated from the minimum detectable activity divided by the number of counts per microgram.
Products De-
JEAN PERDIJON, SAMES, 21 rue Jean Macé, Grenoble (Isère), France
Anal. Chem. 39, 418 (1967)
Anal. Chem. 39. 448 (1967)
Determination of Traces of Lead in A i r by Atomic Absorption Spectrometry T h e procedure reported permits the continuous monitoring of the environmental lead concentration with the determination of as little as 10~" gram per cubic meter of air. T h e method is also applicable to the determination of mercury in air. G E O R G E S T H I L L I E Z , C e n t r a l Research Laboratory, Etablissements Kuhlmann, 92 Levallois-Perret, France
Alternating and Direct Current Polarography of Azobenzene in Indifferent Electrolyte in Dimethylformamide The reduction of azobenzene in D M F proceeds in two one-electron steps. T h e first product is the monoanion of azobenzene; the product of the second electron transfer is a stable, diamagnetic dianion. G O R D O N H . A Y L W A R D , J O H N L. G A R N E T T , and J O H N H . S H A R P , School of Chemistry, University of N e w South W a l e s , Kensington, Australia
Anal. Chem. 39, 427 (1967) Anal. Chem. 39, 457 (1967)
Determination of Antimony by Atomic Absorption Spectrometry
Complexation of Scandium(lll) with 8-Quinolinol
Reported is a study of the factors affecting the determination of Sb in nonferrous alloys by atomic absorption spectrometry. A precision of 2% is reported over the range 0 to 150 ppm of Sb. R. A . M O S T Y N and A . F. C U N N I N G H A M , Chemical ate, Royal Arsenal, London, S.E. 18, England
Inspector-
A n a l . C h e m . 3 9 , 433 ( 1 9 6 7 )
The chelate precipitated when aqueous Sc(III) reacts with 8-quinolinol has been identified as im-(8-quinolinolato) scandium ( I I I ) . I n absolute ethanol the chelate dissociates into a 2:1 chelate and 8-quinolinol. J O H N N . P E T R O N I O , D e p a r t m e n t of Chemistry, University of Rhode Island, Kingston, R. I., and W I L L I A M E. O H N E S O R G E , Department of Chemistry and Laboratory for Nuclear Science, Massachusetts Institute of Technology, C a m b r i d g e , Mass. Anal. Chem. 39, 460 (1967)
Derivation of Expressions for Calculation of the Limiting Detectable Atomic Concentration in Atomic Fluorescence Flame Spectrometry
Detection Limits of Elements in the Spectra of Premixed, Oxy-Acetylene Flames
A quantitative study is reported of the factors affecting the minimum detectable atomic concentration for atomic fluorescence flame spectrometry. Included are sample calculations for Na, Cd, and Cu based on experimental parameters.
Detection limits for 67 elements measured in premixed oxy—acetylene flames have been compared with values from other spectrometric techniques. Forty-three elements are detectable at concentrations of l^tg/ml or less using a flame excitation source.
J . D. W I N E F O R D N E R , M . L P A R S O N S , J . M . M A N S F I E L D , and W . J . M c C A R T H Y , D e p a r t m e n t of Chemistry, University of Florida, Gainesville, Fia. 3 2 6 0 I
V E L M E R A . FASSEL and D A N O L D W . G O L I G H T L Y , Institute for A t o m i c Research and Department of Chemistry, Iowa State University, Ames, Iowa
Anal. Chem. 39, 436 (1967)
Microgram quantities of pyrrolizidine alkaloids and other 3-pyrrolines have been determined using the Polonovsky reaction. T h e base is oxidized to the iV-oxide, which reacts spectrophotometrically with Ehrlich reagent. 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
Circle No. 59 on Readers' Service Card
(1967)
Polarography of Aquodiethyltin(IV) Cation in Aqueous Solution
Spectrophotometric Determination of Unsaturated P y r r o l i d i n e Alkaloids
Anal. Chem. 3 9 , 4 4 3
Anal. Chem. 3 9 , 4 6 6
(1967)
Aqueous aquodiethyltin(IV) undergoes a reversible twoelectron polarographic reduction to a polymeric dicthyltin(II), with the formation of an insoluble polymer coating on the electrode surface. p K values and log Kr values for the chloro and chloroacetate complexes have been evaluated. M I C H A E L D. M O R R I S , Department of Chemistry, The Pennsylvania State University, University Parle, Pa. 16802 Anal. Chem. 39, 4 7 i (1967)
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AC BRIEFS Simultaneous and Independent Potentiostatic Control of Two Indicator Electrodes. Application to the Copper(II)/Copper(I)/ Copper System in 0.5M KCI a t the Rotating Ring-Disc Electrode
An Instrumental Method for Rapid Determination of Carbonate and Total Carbon in Solutions
An analog control system with stabilized operational amplifiers has been developed for the potentiostatic control of ring and disc electrodes. T h e performance of t h e system in CuCl 2 —KCI solution was evaluated in terms of steady-state ring-disc electrode theory. D. T. N A P P , D. C . J O H N S O N , and S T A N L E Y B R U C K E N S T E I N , Department of Chemistry, University of Minnesota, Minneapolis, M i n n . 55455 A n a l . C h e m . 3 9 , 481 ( 1 9 6 7 )
Critique of Chronopotentiometry as a Tool for the Study of Adsorption Reported is a least squares analysis of the minimum conditions for the applicability of chronopotentiometry. Four models for t h e relative rates of reaction of adsorbed and solution species have been investigated. PETER J A M E S L I N G A N E , Pasadena, C a l i f .
California
Institute
of
Technology,
Anal. Chem. 39, 485 (1967)
Reported is a method which uses a dual reaction tube for the determination of both total carbon and carbonate at concentrations between 2 and 100 mg of carbon per liter. The carbon dioxide emerging from the heated reaction tube is swept through an infrared stream analyzer for measurement. C . E. V A N H A L L and V. A . STENGER, A n a l y t i c a l Science Laboratory, The Dow C h e m i c a l C o m p a n y , M i d l a n d , M i c h . A n a l . C h e m . 3 9 , 503 ( 1 9 6 7 )
Transfer Coefficients and Heterogeneous Rate Constants for Cadmium ( I I ) in Various Supporting Electrolytes Evaluated by Phase-Angle Measurements with an A . C . Polarograph The reduction of aqueous C d ( I I ) at the dropping mercury electrode in a variety of supporting electrodes has been used to evaluate transfer coefficients and heterogeneous rate constants. Phase-angle measurements were made at 15 different frequencies and at 3 d.c. potentials. J . K. F R I S C H M A N N and A N D R E W T I M N I C K , Department of Chemistry, Michigan State University, East Lansing, M i c h . 48823 Anal. Chem. 39, 507 (1967)
Use of Organic Additives to Induce Selective Liquid-Liquid Extraction of Niobium with Thenoyltrifluoroacetone
Determination of Total Oxygenates in Organic Materials for Levels Down to 5 ppm by Gas Chromatography
T h e extraction of e5 Nb with 0.5M TTA-xylene from hydrochloric acid solution is markedly enhanced by the addition of w-butanol to the aqueous phase. A A R T J U R R I A A N S E and FLETCHER L. M O O R E , A n a l y t i c a l Chemistry Division, O a k Ridge N a t i o n a l Laboratory, O a k Ridge, Tenn. Anal. Chem. 39, 494 (1967)
Upon elution with helium, pyrolysis products are separated into carbon monoxide and other gases by means of a short molecular sieve column. Total oxygen content down to 10 ppm may be determined without the need for an apparatus blank. C. F. M E A D E , D. A . K E Y W O R T H , V . T. B R A N D , J . R. D E E R I N G , Universal O i l Products C o . , Des Plaines, I I I .
and
A n a l . C h e m . 39, 512 ( 1 9 6 7 )
Counter Double Current Distribution: Effects of Varying Number of Stages Three operational modes of counter double current distribution have been investigated by digital computer simulation. Equations have been derived relating t h e number of stages required, the maximum concentration, and the number of transfers needed to achieve steady state. R. O . BUTTERFIELD, C O N S T A N C E K. T J A R K S , and H . J . D U T T O N , Northern Regional Research Laboratory, Peoria, I I I . 61604
Identification of Polyurethanes by High Resolution Nuclear Magnetic Resonance Spectrometry High resolution nuclear magnetic resonance spectra have been obtained for 11 polyurethanes dissolved in AsCl 3 . Chemical shift data for the compounds are tabulated. E. G . B R A M E , Jr., R. C . F E R G U S O N , and G . J . T H O M A S , Jr., E. I. du Pont d e Nemours & C o . , Inc., Elastomer Chemicals Department, Experimental Station, W i l m i n g t o n , D e l . 19898 A n a l . C h e m . 39, 517 ( 1 9 6 7 )
A n a l . C h e m . 39, 4 9 7 ( 1 9 6 7 )
Time-Resolved Phosphorimetry as a Method of Simultaneous Analysis of Two-Component Mixtures Based on differences in decay times, tryptophan-tyrosine and benzoic aeid-benzaldehyde mixtures _ of various concentration ratios have been analyzed by time-resolved phosphorimetry. T h e logarithm of the phosphorescence signal is plotted vs. time with a relative recovery error of about 3 % .
Notes Gas Chromatographic Analysis of Dilute Aqueous Systems T h e use of activated charcoal in the gas-solid chromatography step permits the concentration of volatiles from large vapor samples for subsequent elution and analysis.
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W . G . J E N N I N G S and H . E. N U R S T E N , D e p a r t m e n t o f Food Science and Technology, University of C a l i f o r n i a , Davis, C a l i f .
A n a l . C h e m . 39, 5 0 0 ( 1 9 6 7 )
A n a l . C h e m . 3 9 , 521 ( 1 9 6 7 )
P. A . ST. J O H N and J . D. W I N E F O R D N E R , D e p a r t m e n t Chemistry, University of Florida, Gainesville, Fia. 3 2 6 0 I
-See ACS Laboratory Guide lor All Products/Sales Office - Circle No. 68 on Readers' Service Card
V O L 3 9 , N O . 4 , APRIL 1 9 6 7
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A Study of Xenon—Mercury Arc as a Continuous Source for Atomic Absorption Spectrometry
Principles of Stationary Phase Selectivity in Gas-Liquid Chromatography Principles of solution theory, particularly the FloryHuggins concept, servo as a guide in the selection of sta tionary phases for gas-liquid chromatography. S T A N L E Y H . L A N G E R , Department of C h e m i c a l University of Wisconsin, Madison, W i s . 53706
BRIEFS
Engineering,
A n a l . C h e m . 39, 5 2 4 ( 1 9 6 7 )
The hollow cathode source has been compared with the xenon-mercury arc for Ca, Na, Cu, and Zn. Optimum fuel-oxygen ratios, burner heights, sensitivities, and interferences are reported. C . W . F R A N K , W . G . S C H R E N K , and C . E. M E L O A N , Kansas Agricultural Experiment Station, Department of Chemistry, Kansas State University, M a n h a t t a n , Kan. A n a l . C h e m . 3 9 , 534 ( 1 9 6 7 )
Simultaneous Determination of Tin and Lead Using Cyclic Stationary Electrode Polarography Spectrophotometry Determination of Manganese(VII) by Reduction with 6-Methoxy2-Methylthio-4-Pyrimidine Carboxylic Acid M n O r is rapidly reduced to MnOr 2 by the pyrimidine derivative, M M P C A . The reaction permits the spectro photometry or titrimetric determination of manganese.
A method for the simultaneous determination of P b and Sn employs as supporting electrode a formate buffer containing pyrogallol. The lead and tin waves are separated for the determination of concentrations up to 1.6 χ l f r W . S I D N E Y L. PHILLIPS, I B M Corp., Systems Development Division, Poughkeepsie, N . Y. I 2 6 0 2
O K K U N G K. C H U N G and C L I F T O N E. M E L O A N , Department of Chemistry, Kansas State University, M a n h a t t a n , Kan. A n a l . C h e m . 3 9 , 525 ( 1 9 6 7 )
Internal Standard Techniques for Determination of Oxygen in Magnesium, Steel, and Titanium by Activation Analysis
A n a l . C h e m . 39, 536 ( 1 9 6 7 )
Estimation of Molybdenum in Biological Material by Neutron Activation Analysis ""Mo was measured by gamma detection of the daughter isotope, °°mTc. A second extraction of 09m Tc after equilibrium of the parent-daughter couple prevented the separation and counting of any radioeontaminant. H . D. L I V I N G S T O N and H A M I L T O N S M I T H , Department of Forensic M e d i c i n e , Glasgow University, Glasgow, W . 2 , Scot land.
T h e activation product of a sample matrix suitable for 14-MeV activation serves as an internal standard for flux and sample weight correction. No sample weighing is required. BRYCE L. T W I T T Y and K E N N E T H M . FRITZ, N a t i o n a l Lead C o . of O h i o , Cincinnati, O h i o 4 5 2 3 9 A n a l . C h e m . 39, 527 ( 1 9 6 7 )
A n a l . C h e m . 39, 538 ( 1 9 6 7 )
Correspondence "Krypton Triode" as Selective Detector for Gas Chromatography C . D. P E A R S O N and R. S. SILAS, Phillips Petroleum C o . , search Division, Analysis Branch, Bartlesville, O k l a .
Solvent Fractionation of Girard T Derivatives of Carbonyl Compounds Using Dimethyl Sulfoxide A nonaqueous system has been developed for the separa tion of carbonyl and noncarbonyl compounds. Carbonyl compounds react with Girard Τ reagent to form a polar hydrazone. S. F. O S M A N and J . L. B A R S O N , Eastern Utilization Research and Development Division, Agricultural Research Service, U. S. De partment of Agriculture, Philadelphia, Pa. 191 18 A n a l . C h e m . 3 9 , 530 ( 1 9 6 7 )
A n a l . C h e m . 3 9 , 540
Re
(1967)
Re-Evaluation of Chronopotentiometric Data for Adsorption of Riboflavin PETER J A M E S L I N G A N E , Gates and Crellin Laboratories Chemistry, California Institute of Technology, Pasadena, C a l i f . A n a l . C h e m . 39, 541
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(1967)
Recommendations for Reporting Thermal Analysis Data H . G . M c A D I E , O n t a r i o Research Foundation, 43 Queen's Park Crescent East, Toronto 5, C a n a d a A n a l . C h e m . 39, 543
Determination of Ephedrine and Certain Related Compounds by Ultraviolet Spectrophotometry A rapid, spectrophotometry method is reported for the determination of ephedrine and related compounds hav ing a benzyl alcohol group. Recovery values and inter ferences are tabulated. J A C K E. W A L L A C E , Forensic Toxicology Branch, U S A F demiological Laboratory, Lackland A i r Force Base, Texas
Epi
A n a l . C h e m . 39, 531 ( 1 9 6 7 )
(1967)
Aids for Analytical Chemists Gas Chromatographic Method for Small Amounts of W a t e r Vapor in Air D. E. BURKE, G . C . W I L L I A M S , and C . A . PLANK, Department of Chemical Engineering, University of Louisville, Louisville, Ky. A n a l . C h e m . 39, 544
VOL. 3 9 , N O . 4 , APRIL 1 9 6 7
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Exchangeable Injection Port Cartridge for Gas Chromatographic Determination of Volatile Substances in Aqueous Fluids GERHARD FREUND, Department of Medicine, University Florida College of Medicine, Gainesville, Fia. 3260I
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Anal. Chem. 39, 545 (1967)
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Rapid Sonication Technique for Liquid Scintillation Counting of Carbon-14-Labeled Barium Carbonate J O H N B. ALLRED, Department of Chemistry, Oklahoma University, Oklahoma City, Okla.
Anal. Chem. 39, 547 (1967)
Nitrogen Analysis of Nitrate Esters by Micro-Dumas Combustion
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Anal. Chem. 39, 548 (1967)
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Qualitative Detection of Boron via a Crystalline Derivative GEORGE VOGEL, Department of Chemistry, Chestnut H i l l , Mass. 02167
Boston College,
Anal. Chem. 39, 549 (1967)
Spectrophotometric Assay of the Triphenylmethyl Group ROBIN M. SAUNDERS and HENRY P. SCHWARZ, Biochemistry Department, Philadelphia General Hospital, Philadelphia, Pa., and J O H N C. STEWART, Twyford Laboratories, Twyford Abbey Road, London, England For catalytic reduction, condensation and other reactions with hydrogen at pressures up to 5 atm. (60 psig.) in 250 or 500 m l . glass bottles. Also available in a larger unit with interchangeable 1 and 2 liter bottles. Write or phone ( 3 0 9 ) 762-7716 for the latest issue of Spec. 3900 describing the recently improved models of this widely used hydrogenator.
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Anal. Chem. 39, 550 (1967)
Anomalous Calibration Curves in Gas Chromatography of High-Boiling Compounds M. M. E. METWALLY, C. H. AMUNDSON, and T. RICHARDSON, Department of Food Science and Industries, University of Wis consin, Madison, Wis. Anal. Chem. 39, 551 (1967)
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