A C BRIEFS

Chemistry, State University of New York, Buffalo, N. Y. 14214 ... try, Purdue University, Lafayette, Ind. 47907 ... Department, Southwestern College, ...
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A C BRIEFS Highlights of Articles in This Issue

Fast Flow Studies of Biological Reactions with Ion-Selective Membrane Electrodes

Direct Analysis of Thin Layers by Spark Source Mass Spectrography

A new flow system using liquid membrane electrodes is con­ structed and evaluated for reactions involving divalent metal ions and biologically important ligands.

A precision scanning device, which can be mounted in t h e existing source unit and allows the uniform erosion of the surface of a plane parallel slice between 2 and 3 cm in di­ ameter, is described.

BERNARD FLEET and GARRY RECHNITZ, Department of Chemistry, State University of New York, Buffalo, Ν. Y. 14214 Anal. Chem., 42, 690 (1970)

Titanium Determination with Disodium-1,2Dihydroxybenzene-3,5-Disulfonate (Tiron) in Oxalic Acid Solution In solutions stabilized with oxalic acid, from 2 to 100 jug of titanium as the tiron complex is determined spectrophotometrically in the presence of diverse metallic ions. LEWIS J. CLARK, U. S. Naval Research Laboratory, Wash­ ington, D. C. 20390 Anal. Chem., 42, 694 (1970)

Spectrophotometric Determination of Sulfite with 4,4-Dithiodipyridine and 5,5'Dithiobis(2-Nitrobenzoic Acid) Sulfite can be determined spectrophotometrically in the low /xg/ml range by reaction with 4,4'-dithiodipyridine or 5,5'dithiobis-(2-nitrobenzoic acid) to displace a thiol whose a b ­ sorption is measured. RAY E. HUMPHREY, MELBOURNE H. WARD, and WILLIE HINZE, Department of Chemistry, Sam Houston State Uni­ versity, Huntsville, Texas 77340

J. B. CLEGG, E. J. MILLETT, and J. A. ROBERTS, Mullard Research Laboratories, Redhill, Surrey, England Anal. Chem., 42, 713 (1970)

Internal Standardization in Atomic Emission and Absorption Spectrometry This paper describes the utilization of internal standardiza­ tion techniques to compensate for most of the error sources associated with the flame and nebulization processes. FREDERIC J. FELDMAN, Instrumentation Beckman Instruments, Lexington, Mass.

Laboratory,

Anal. Chem., 42, 719 (1970)

Nuclear Magnetic Double Resonance Study of Water Movement in an Ion Exchange Resin System The purpose of this investigation was to study by N M R the exchange of water in Dowex 50W resin and in addition o b ­ tain the longitudinal relation time (7Ί) for the two types of water. R. W. CREEKMORE and C. N. REILLEY, Department of Chemistry, University of North Carolina, Chapel Hill, N. C. 27514 Anal. Chem., 42, 725 (1970)

Anal. Chem., 42, 698 (1970)

New Spectrophotometric Method for the Determination of Proline in Tissue Hydrolyzates Proline from hydrolysates reacts with ninhydrin in buffered brine to give reproducible yields of pigment as a basis of spectrophotometric analysis. Nitrozation removes interfer­ ing primary amino-compounds. /MANUEL BERGMAN and ROY LOXLEY, Safety in Mines Research Establishment, Ministry of Technology, Sheffield, England Anal. Chem., 42, 702 (1970)

Design and Evaluation of a Stabilized, Dual Detector Chemiluminescence Spectrophotometer

Application of an On-Line Computer to the Automation of Analytical Experiments The application of on-line computers is compared with the requirement of analytical experiments. New approaches are suggested for certain phases of these applications. G. P. HICKS, A. A. EGGERT, and E. C. TOREN, JR., De­ partment of Medicine and Department of Chemistry, Uni­ versity of Wisconsin, Madison, Wis. 53706 Anal. Chem., 42, 729 (1970)

Semiquantitative Analysis of Mixed Gamma-Ray Spectra by Computerized Learning Machines

The design and construction of a spectrophotometric system based upon a highly linear, wide dynamic range photomultiplior system is described.

The learning machine method is applied to the resolution of complex gamma-ray spectra for the semiquantitative de­ termination of 17 elements b y fast neutron activation analy­ sis.

R. E. SANTINI and H. L. PARDUE, Department of Chemis­ try, Purdue University, Lafayette, Ind. 47907

L. E. WANGEN and T. L. ISENHOUR, Department of Chem­ istry, University of Washington, Seattle, Wash. 98105

Anal. Chem., 42, 706 (1970)

Anal. Chem., 42, 737 (1970) ANALYTICAL CHEMISTRY, VOL. 42, NO. 7, JUNE 1970 · 11 A

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BRIEFS

Rapid Determinations of the Trace and Minor Elements in Tin—Lead Solders by Atomic Absorption Spectrometry

Notes

In this investigation, an attempt was made to determine as many elements as possible in the solder samples, and also to improve the precision of the analysis by using atomic absorption spectrometry.

Development of an X-Ray Emission Spectrography Method for the Determination of Molybdenum in Oils

JAE Y. HWANG and LINDA M. SANDONATO, Instrumentation Laboratory, Inc., 113 Hartwell Ave., Lexington, Mass. 02173 Anal. Chem., 42, 744 (1970)

DOBRINKA JOVANOVIC, Institute for Technology of Nuclear and other Mineral Raw Materials, Beograd—Franse D'Epere-a street 86, Yugoslavia Anal. Chem., 42, 775

Weighted Least Squares Curves Fitting Using Functional Transformations This paper presents the method of weighted least squares curve fitting using functional transformations. Several specific examples are given, and the application of the method to experimental curve fitting and the development of calibration curve is indicated. PETER C. JURS, Department of Chemistry, The Pennsylvania State University, University Park, Pa. 16802 Anal. Chem., 42, 747

A direct method was used to determine the concentration of molybdenum in oils. Scattered radiation was used as the internal standard. The limit of detection is approximately 70 ppm of molybdenum.

(1970)

(1970)

Mass Spectrometric Determination of Zirconium, Hafnium, and Titanium in Mixtures Using the Integrated Ion Current Method Mixtures of the benzoyl trifiuoroacetonates of zirconium, hafnium, and titanium are determined using the integrated ion-current technique with an accuracy of 10-15%. M. G. ALLCOCK, RONALD BELCHER, J. R. MAJER, and ROGER PERRY, Chemistry Department, University of Birmingham, P.O. Box 363, Edgbaston Birmingham, 15 Anal. Chem., 42, 776

(1970)

Identification of Polycyclic Aromatic and Heterocyclic Crude Oil Carboxylic Acids

Ferrozine—A New Spectrophotometry Reagent for Iron

Modern methods molecular spectroscopy, including high resolution mass spectroscopy, led to identification of compound classes of carboxylic acids hitherto unknown in petroleum and traditionally labeled "Naphthenic Acids."

The purpose of this work was the synthesis of a colorimetric reagent for iron which would have a sensitivity comparable to that of the 2,4,6-tris(2-pyridyl)-l,3,5-lriazine, but which would also cost less than other reagents commercially available.

WOLFGANG K. SEIFERT and RICHARD M. TEETER, Chevron Oil Field Research Co., Richmond, Calif. 94802 Anal. Chem., 42, 750

(1970)

Anal. Chem., 42, 779

713

(1970)

Spectrophosphorimetric Measurement of Niobium Oxinate at Liquid Nitrogen Temperature for Determination of Microgram Amounts of Niobium

Potentiometric Study of Base Strengths in Binary Solvent, Acetic Anhydride—Acetic Acid The response of the glass indicator electrode to changes in acetate ion concentration approximates the Nernst relationship for the binary solvent mole fraction range of 1.0 to 0.28 in acetic acid. ORLAND W. KOLLING and WILTON L. COOPER, Chemistry Department, Southwestern College, Winfield, Kan. 67156 Anal. Chem., 42, 758

LAWRENCE L. STOOKEY, Hach Chemical Company, South Duff Avenue, Ames, Iowa 50010

(1970)

Real-Time Computer Prediction of End Points in Controlled-Potential Coulometry On-line analog and digital computational techniques were developed for predicting the final value of charge in controlled-potential coulometric determinations. F. B. STEPHENS, FREDI JAKOB, L. P. RIGDON, and J. E. HARRAR, Chemistry Department, Lawrence Radiation Laboratory, University of California, Livermore, Calif. 94550 Anal. Chem., 42, 764 (1970)

Microgram amounts of niobium are determined by measurement of the phosphorescence at —196 °C of niobium oxinate in an ether—iso-pentene—alcohol glass. Optimum conditions, effect of foreign ions, precision, and accuracy have been established. G. F. KIRKBRIGHT, J. V. THOMPSON, and T. S. WEST, Chemistry Department, Imperial College, London, S.W. 7., U. K. Anal. Chem., 42, 782 (1970) Spectrofluorimetric Determination of Submicrogram Amounts of Zirconium with Calcein Blue Measurement of the fluorescence intensity at 405 nm of the zirconium complex of Calcein Blue provides a rapid method for the determination of zirconium down to the 0.1 ppb level. R. V. HEMS, G. F. KIRKBRIGHT, and T. S. WEST, Chemistry Department, Imperial College, London S.W. 7., U. K. Anal. Chem., 42, 784 ANALYTICAL CHEMISTRY, VOL. 42, NO. 7, JUNE 1970

(1970) ·

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AC BRIEFS Coulometric and Titrimetric Reduction of Iridium Fumed in Perchloric Acid This paper is a critical examination of the reactions of iridium on fuming in perchloric acid and an a t t e m p t to re­ solve the previous conflicting claims. An analytical method based on fuming has been developed. EDWARD J. ZINSER and JOHN A. PAGE, Department of Chemistry, Queen's University, Kingston, Ontario, Canada Anal. Chem., 42, 787

(1970)

Bulk Susceptibility Corrections in Nuclear Magnetic Resonance Experiments Using Superconducting Solenoids The effect of sample/field configuration on the bulk sus­ ceptibility corrections for chemical shifts in nuclear mag­ netic resonance experiments has been considered for cyclindrical samples when the sample axis is perpendicular and parallel to the direction of the polarizing magnetic field. DAVID H. LIVE and SUNNEY I. CHAN, Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, Calif. 91109 Anal. Chem., 42, 791

Semi-Automatic Spectrophotometric Method for Determination of Hydroxide and Aluminum in Sodium Aluminate Solutions Dihydroxytartaric acid 2,4-dinitrophenylosazone (Alkalone) is used as the spectrophotometric reagent specific for the determination of hydroxyl ion. The free hydroxide is de­ termined directly and the aluminum indirectly by using sodium gluconate as a complexing reagent with the release of an equivalent amount of hydroxide. RICHARD S. DANCHIK and R. T. OLIVER, Analytical Chem­ istry Division, Alcoa Research Laboratories, New Kensing­ ton, Pa. 15068 Anal. Chem., 42, 798 (1970)

Quantitative Determination of Ethoxyl in O-Ethylcellulose and in Ethyl-Hydroxyethyl Cellulose The per cent ethoxyl in ethylcellulose and ethyl-hydroxyethyl cellulose is determined by gas chromatography. The relative standard deviation is 2 % . HARRY JACIN and JOHN M. SLANSKI, Research Division, American Machine & Foundry Company, The Morehead Patterson Center, Springdale, Conn.

(1970)

Anal. Chem., 42, 801

(1970)

Polystyrene Sulfonates as Stable Polarographic Maxima Suppressors in the Determination of Periodate and Cobalt(ll)

Boron Trifluoride—Methanol Tranesterification as a Means of Characterizing Alcohol Sulfate Detergents

The sodium salts of some polystyrene sulfonic acids have been found to be particularly useful as maxima suppressors in the polarographic determination of periodate owing mainly to the fact that they are not oxidized by the perio­ date ; but they also have some other desirable properties.

The combined alcohols of alcohol sulfate detergents can be conveniently, rapidly, and reproducibly released by transesterifieation in boron trifluoride-methanol solution. These are then characterized by gas chromatography, providing type identification or quality control.

R. D. CORLETT, W. G. BRECK, and G. W. HAY, Queen's University, Kingston, Ontario, Canada

C. B. PUCHALSKY, Uniroyal royal, Inc., Naugatuck, Conn.

Anal. Chem., 42, 792

(1970)

Complex Formation in Lead Sulfate Solutions Conductometric and potentiometric studies of lead sulfate complex formation have been made at 25 °C. The thermo­ dynamic association constant, K(PbSOi) is 561 ± 21 mole"1 from conductivities and 500 ± 55 mole" 1 using the lead ion electrode. G. GARDNER and G. H. NANCOLLAS, Chemistry Depart­ ment, State University of New York at Buffalo, Ν. Υ. 14214 Anal. Chem., 42, 794 (1970)

Chemical,

Division

of Uni-

Anal. Chem., 42, 803

(1970)

Polarography of Phthalic Anhydride Molecule in Water-Acetone Media In water containing acetone media, phthalic anhydride gives one or two polarographic waves, depending on p H and sol­ vent composition. Waves are due to electroreduction of the unhydrolyzed molecule. DEMETRIOS KYRIACOU, Research Laboratories, Chemical Company, Pittsburg, Calif.

The Dow

Anal. Chem., 42, 805

(1970)

Experimental Evaluation of Effect of Double-Layer Charging on Chronopotentiograms

Detection Limits for Gamma-Ray Spectral Analysis

The adequacy of a model for recently published theory of chronopotentiometry with double-layer charging has been evaluated experimentally. Very good agreement between theory and experiment is reported.

The purpose of this study was to obtain expressions for the limits of detection and quantitative determination for gamma-ray spectral analysis. In particular, working rela­ tions were obtained for the summing-channels method of photopeak area determination.

M. L. OLMSTEAD and R. S. NICHOLSON, Chemistry De­ partment, Michigan State University, East Lansing, Mich. 48823 Anal. Chem., 42, 796 (1970)

V. G. ROGERS, Departments of Physics and Chemical En­ gineering, Brigham Young University, Provo, Utah 84601 Anal. Chem., 42, 807 ANALYTICAL CHEMISTRY, VOL. 42, NO. 7, JUNE 1970

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A C BRIEFS

Whatman Reliability in a Precision Filter System for the Small-scale User

NOW-

Correspondence Microanalysis of Solids by Atomic Absorption and Emission Spectroscopy Using an R. F. Furnace G. H. MORRISON and YAIR TALMI, Department istry, Cornell University, Ithaca, Ν. Y. 14850

of Chem­

Anal. Chem., 42, 809 (1970)

Aids for Analytical Chemists Modification of a 3 0 MHz Plasma Torch for Gas Analysis and Comparison with a 2 4 5 0 MHz Plasma C. DAVID WEST, Department of College, Los Angeles, Calif. 90041

Chemistry, Occidental

Anal. Chem., 42, 811 (1970)

W Whatman

GAMMA-12 A Simple Automatic Hydrogénation Apparatus G. W. Η. Λ. MANSVELD, A. P. G. KIEBOOM, W. TH. M. DE GROOT, and HERMAN VAN BEKKUM, Laboratory of Or­ ganic Chemistry, Delft University of Techno/ogy, The Netherlands Anal. Chem., 42, 813 (1970)

A major innovation in high performance in-line f i l t e r units, the new Whatman Gamma-12 is designed specifically for high efficiency particle removal in a wide variety of environments. It uses disposable glass microfiber filter tube elements to achieve exceptionally high flow rates and remark­ ably high particle retention. Whatman Gamma-12 can be used in-line or as an inlet or exhaust filter... it can be fitted with four grades of filter element covering a wide range of particle sizes, from 8 microns down to sterility levels.

A "Do-lt-Yourself" Electron Paramagnetic Resonance Cell J. F. AMBROSE and D. D/LLARD, Department of Chemis­ try, Kansas University, Lawrence, Kan. 66044, and A. K. CARPENTER and R. F. NELSON, Department of Chemis­ try, Sacramento State College, Sacramento, Calif. 95819 Anal. Chem., 42, 814 (1970)

The Whatman Gamma-12 unit has a transparent bowl that allows continuous inspection of the filter element... replacement of the filter tube is simple, inexpensive, and no associated hardware is thrown away with the filter medium . . . the complete unit can be autoclaved. Gamma-12 is used for sterilization of air and main­ tenance of sterile environments . . . for the removal of microorganisms and particulate matter from water and other liquids . . . for virtually any filtra­ tion application in the laboratory or process plant. For the best results .. . the cleanest fluids . . . you need the finest in-line filter: Whatman Gamma-12. For further information on this remarkable new unit, call or write for our free Gamma-12 brochure.

A Syringe Pycnometer for the Accurate Weighing of Milligram Quantities of Aqueous Solutions G. C. LOWENTHAL and VALDAS PAGE, Research Estab­ lishment, Australian Atomic Energy Commission, Lucas Heights, N. S. W. 2232, Australia Anal. Chem., 42, 815 (1970)

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H. Reeve Angel & Co., Inc. 9 Bridewell Place, Clifton, N.J. 07014 Sole Distributor in North America ©Whatman is a registered trademark of W. & R. Balston, Ltd., England. Circle No. 129 on Readers' Senice Card

ANALYTICAL CHEMISTRY, VOL. 42, NO. 7, JUNE 1970

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