AC
BRIEFS Highlights of the scientific a n d technical articles in this issue
Complex Reactions in Analytical Chemistry
A summary of the Twelfth Annual Summer Symposium is presented, dealing with 16 papers related to complex reactions in analytical chemistry. Papers treated various aspects of analytical techniques, including complex titrations, polarography of metal complexes, and metalfluorochromic indicators along with others. C. N. RE1LLEY, University of North Carolina, Chapel Hill, N. C. Anal. Chem. 3 2 , 2 ( 1 9 6 0 )
Quantitative Analysis of Fischer-Tropsch Catalysts by X - R a y Diffraction. Determination of «-Iron, Magnetite, and Iron Carbides
X-ray diffraction methods are assessed for their sensitivity and accuracy in catalyst analysis for α-iron, magnetite, and iron carbides. One analysis involves 4 hours' time and a standard deviation of 3 to 10% is obtained when a diffractometer is used. F. H. HERBSTEIN, JACQUES SMUTS, and J. N. V A N NIEKERK, National Physical Research Laboratory, Pretoria, South Africa Anal. Chem. 3 2 , 2 0 ( 1 9 6 0 )
Relationships between Metal Complex Stability and the Structure of the Complexing Agents
The tendency of the various metal ions to replace a molecule of water with a ligand group is investigated with the aid of complex stabilities. A comparison shows that oxygen donors and fluorides are general complexing agents, combining with any metal ion with a charge more than 1. Bond stability increases with the basicity of the ligand atom. GEROLD SCHWARZENBACH, Technische Hochschule, Zurich, Switzer land Anal. Chem. 3 2 , 6 ( 1 9 6 0 )
Determination of Radioactivity of Saline Waters
The radioactive content of sea water is determined by a screening procedure employing various precipita tion techniques. Cations are removed as sulfides from ammoniacal solution, while strontium, barium, and radium are precipitated as carbonates. Cesium is separately removed with silicotungstic acid. V. J. S O D D , A. S. G O L D I N , and R. J. VELTEN, U. S. Department of Health, Education, and W e l f a r e , Cincinnati, Ohio Anal. Chem. 3 2 , 25 ( 1 9 6 0 )
High-
Cathodic Action of the Phenylenediamine Dihydrochlorides at the Dropping Mercury Electrode
The use of a modulated off-balance radiofrequency signal originating from the detector side of a high frequency impedance bridge is studied as a method for performing high frequency titrations. Important advantage is that data are obtained as voltmeter readings and are readily plotted against volume without calculations.
A polarographic method is devised for determining the three isomers of phenylenediamine dihydrochlorides. The isomers dissolved in trimethyl bromide—gelatin solution give well defined waves upon reduction at a dropping mercury electrode.
Use of an Unbalanced Frequency Titrimetry
Bridge
Circuit
in
J. M. WALKER, J. L. LAMBERT, and L. D. ELLSWORTH, Kansas State University, Manhattan, Kan. Anal. Chem. 3 2 , 9 ( 1 9 6 0 )
Low Voltage Aromatics
Mass Spectrometric
Sensitivities
of
A study employing low voltage mass spectrometric techniques indicates a correlation of low voltage sensi tivity data with molecular properties of aromatic com pounds. Aromatic ring substitutions on hydrocarbons and nonhydrocarbons are evaluated, permitting low voltage sensitivities to be predicted. G. F. CRABLE, G . L. KEARNS, and M. S. NORRIS, Gulf Research & Development Co., Pittsburgh, Pa. Anal. Chem. 3 2 , 13 ( 1 9 6 0 )
S. R. COOPER and O . F. FOWLKES, Howard University, Washington, D. C. Anal. Chem. 3 2 , 2 6 ( 1 9 6 0 )
Qualitative Identification Their Dosage Forms
of Local Anesthetics
in
Local anesthetics in dosage forms, including tablets, ointments, jellies, and solutions, are qualitatively deter mined by various analytical methods. Rapid separation is obtained by using paper chromatography. Identifica tion is made by ultraviolet spectrophotometry. Applica tion is to anesthetics used primarily in dentistry. H. M. KOEHLER and E. G . FELDMANN, American Dental Association, Chicago 11,111. Anal. Chem. 3 2 , 2 8 ( 1 9 6 0 )
Colorimetric Determination of 3,5-Dinitro-o-toluamide and Related Dinitro Compounds Modification of Spectrofluorometric Determination of Aminochromes in H u m a n Plasma
The spectrofluorometric method for determining amino chromes is modified to be applicable to whole tissue. A reagent change eliminates interference encountered in the reagent blank. Indoles do not interfere. A. N. PAYZA and MARGARET M A H O N , University Hospital, Saskatoon, Saskatchewan, C a n a d a Anal. Chem. 3 2 , 1 7 ( 1 9 6 0 )
Isomers of dinitrotoluamide are distinguished and quan titatively determined by colorimetric procedure. The sample is reacted with dimethylformamide and methylamine. The resulting complex is measured at several wave lengths and compared with reference standard readings, allowing the calculation of individual isomers in the mixture. G . N. SMITH, The Dow Chemical Co., Midland, Mich. Anal. Chem. 3 2 , 3 2 ( 1 9 6 0 )
VOL. 32, NO. 1, JANUARY 1900
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BRIEFS Determination of Calcium and Magnesium w i t h (Ethylenedinitrilo)tetraacetic Acid. Studies in A c curacy
Determination of Bismuth Based on the Reduction of Molybdophosphoric Acid. A n Absorptiometric Method
In the titrimetric procedure for calcium and magnesium with EDTA, accuracy is affected by competing equilibria at the color end points and by coprecipitation phe nomena. These factors are studied to develop a precise and accurate procedure for determining calcium and magnesium in mixtures.
An absorptiometric method is devised for determining bismuth based on its enhancement of the molybdophos phoric acid reduction of absorbic acid. Detection range is between 0.02 to 1.2 mg. per 50 ml. with reproducible deviation from Beer's law. R. H. CAMPBELL with M. G. MELLON, Purdue University, Lafayette, Ind.
L. L. LEWIS and L. M . MELNICK, United States Steel Corp., Monroeville, Pa. Anal. Chem. 3 2 , 3 8 ( 1 9 6 0 )
Anal. Chem. 3 2 , 5 4 ( 1 9 6 0 )
Determination of Carbon-14 and Tritium in Blood and Other Whole Tissues. Liquid Scintillation Counting of Tissues
Determination of Cadmium in Zinc Concentrates a n d Other Zinc-Rich Materials
Liquid scintillation counting procedure is used for deter mining carbon-14 and tritium in various types of tissues. Major points of investigation are dissolution in solvent systems, color quenching effects of solutions, and count ing efficiency related to different tissues. Whole tissue counting is convenient for assaying large numbers of samples.
An ion exchange procedure is described for the separation of cadmium in zinc concentrates. Using an iodide medium, the cadmium iodide complex is recovered in the first eluate from a strongly acidic cation exchange col umn. All other constituents are retained by the resin. SILVE KALLMANN, HANS OBERTHIN, and ROBERT LIU, Ledoux & Co., Teaneck, N . J. Anal. Chem. 3 2 , 5 8 ( 1 9 6 0 )
R. J. HERBERG, Lilly Research Laboratories, Indianapolis, Ind. Anal. Chem. 3 2 , 4 2 ( 1 9 6 0 )
Determination of Platinum, Sulfur, and Chlorine in Platinum Reforming Catalysts
The platinum content in petroleum conversion catalysts is determined by a colorimetric procedure. Platinum chloride is volatilized at high temperature, and the evolved gas is absorbed in acid solution and reacted with pnitrosodimethylaniline. Modifications of the procedure permit determination of sulfur and chlorine. A. L. C O N R A D and J. K. EVANS, The Standard Oil Co. (Ohio), Cleve land, Ohio Anal. Chem. 3 2 , 4 6 ( 1 9 6 0 )
Volumetric Determination of Isophthalic and Other Dicarboxylic Acids in Modified A l k y d Resins
Nonaqueous titration in ethylene glycol-ethyl alcohol medium affords a rapid method for determining dicar boxylic acids in modified alkyd resins. The volumetric procedure eliminates the need for drying, weighing, and cooling filtration crucibles, and compares favorably with the ultraviolet method. G . G . ESPOSITO and M. H. S W A N N , Aberdeen Proving Ground, Aberdeen, M d . Anal. Chem. 3 2 , 4 9 ( 1 9 6 0 )
A n Indirect Absorptiometric Method for the Determination of Boron
Boron at concentrations between 0.1 and 2.5 mg. per 50 ml. is determined by an indirect absorptiometric procedure. Interference from elements forming strong fluoride complexes or heterpoly acids is eliminated by methyl borate separation. Variables and optimum procedural conditions are established. R. H. CAMPBELL with M. G. MELLON, Purdue University, Lafayette, Ind. Anal. Chem. 3 2 , 5 0 ( 1 9 6 0 )
Automatic Recording Velocity-Servo Potentiometric Titrator
A new automatic recording velocity-servo potentiometric titrator is constructed utilizing a servomechanism to control the rate of addition of titrant. The titrator is designed for general potentiometric methods, being applicable for radioactive and nonradioactive samples on a micro or macro basis. M. T. KELLEY, D. J. FISHER, and Ε. Β. W A G N E R , O a k Ridge National Laboratory, O a k Ridge, Tenn. Anal. Chem. 3 2 , 61 ( 1 9 6 0 )
Cation Exchange Elution of Magnesium Hydrochloride and Perchloric Acids
Ion
by
A detailed investigation is presented for the elution of magnesium (II) from sulfonic cation exchange resin with hydrochloric and perchloric acids. Effects due to equilibrium changes and those attributable to varia tion in the rate of reaction are the major concern of the study. C. K. M A N N , Florida State University, Tallahassee, Fla. Anal. Chem. 3 2 , 6 7 ( 1 9 6 0 )
Use of Cellulosic Ion Exchangers for Determination of Quaternary A m m o n i u m Compounds
Cellulosic ion exchange columns are used for the separa tion of long-chain quaternary ammonium compounds from solutions. The compounds are resolved with alcoholic hydrochloric acid, reacted with bromophenol blue, and spectrophotometrically determined at 603 αιμ. L. D. METCALFE, Armour and Co., Chicago 9 , III. Anal. Chem. 3 2 , 7 0 ( 1 9 6 0 )
VOL. 32, NO. 1, JANUARY 1960
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BRIEFS Standard Titanium-Hydrogen Samples
A procedure is outlined for the preparation of individual titanium-hydrogen standards. Comparative analysis for hydrogen involving 20 laboratories indicates agree ment on results between 3 and 6%. M . J. TRZECIAK, Battelle Memorial Institute, Columbus 1 , Ohio Anal. Chem. 3 2 , 7 2 ( 1 9 6 0 )
Analyses of o-Xylene Oxidation Products
Photometric Indicator Titration of Weak Bases in Acetic Acid. The Modified Type II Plot
A modified photometric indicator titration procedure for determining weak bases in acetic acid takes into account solvolysis of the salt formed during titration. A con venient measure of basicity is found in the salt formation constant. Acetamide, urea, dimethylpyrone, and other weak bases are titrated using as indicators Sudan III, Nile Blue A, />-naphtholbenzein, and malachite green. K. A. C O N N O R S Madison, Wis.
and TAKERU HIGUCHI, University of
Wisconsin,
Anal. Chem. 3 2 , 9 3 ( 1 9 6 0 )
Infrared and mass spectrometric techniques are com bined for the analyses of separated o-xylene oxidation products. Phthalide is identified as the major compo nent and is quantitatively determined. Also present are C16 and C16 diaryl hydrocarbons and o-xylyl-o-toluate. H. E. LUMPKIN and D. E. N I C H O L S O N , Humble Oil & Refining Co., Baytown, Tex. Anal. Chem. 3 2 , 7 4 ( 1 9 6 0 )
Identification of Fragments in the Mass Spectra of Dialkyldiboranes
The identification of fragments in the mass spectra of 1,1-and 1,2-dimethyldiboranes and their ethyl analogs is enhanced by using isotopically labeled compounds. Certain molecular rearrangements in the 1,2-dialklboranes are noted. C. O . W I L S O N , Jr., and I. SHAPIRO, Olin Mathieson Chemical Corp., Pasadena, Calif. Anal. Chem. 3 2 , 7 8 ( 1 9 6 0 )
Determination of Nickel and Cobalt in High-Alloy and Stainless Steels
A titrimetric method is developed for determining nickel and cobalt in high-alloy and stainless steel. The metals are isolated by dimethylglyoxime precipitation and separated by ion exchange. The titration is conducted with 0.03ΛΙ EDTA. L. L. LEWIS and W . A. STRAUB, United States Steel Corp., Monroeville, Pa. Anal. Chem. 3 2 , 9 6 ( 1 9 6 0 )
Application of EDTA to Titrimetric Determination of Nickel in Nonferrous Alloys
A titrimetric procedure uses EDTA for determining nickel in nonferrous alloys. Nickel is separated from the sample solution by double precipitation with di methylglyoxime. A sharp and reproducible end point is obtained with Cal Ver I indicator. Cobalt, iron, and tin do not interfere.
Determination of Glutethimide in Biological Fluids
A rapid, sensitive, and specific method is devised for determining glutethimide in blood plasma and urine. Glutethimide is extracted with chloroform and impurities are removed. Determination is based on its ultraviolet spectrum and rate of hydrolysis in alcoholic potassium hydroxide. L. R. GOLDBAUM and M. A. WILLIAMS, Armed Forces Institute of Pathology, Washington 2 5 , D. C , and THEODORE KOPPANYI, George town University School of Medicine and Dentistry, Washington, D. C.
V. A. NELSON and L. J. WRANGELL, Allis-Chalmers Manufacturing Co., Milwaukee, Wis. Anal. Chem. 3 2 , 9 9 ( 1 9 6 0 )
Multifunction Titrator
Automatic
Recording
Photometric
Anal. Chem. 3 2 , 8 1 ( 1 9 6 0 )
An automatic recording photometric titrator is described for use in colorimetric, nephelometric, and chemiluminescent indicator titrimetry. The instrument directly plots absorbance of solution against milliliters of titrant added. Accuracy and precision compare with those achieved by manual titration.
Spectrophotometric Analysis of Multicomponent Systems Using the Least Squares Method in Matrix Form. The Ergosterol Irradiation System
P. W . MULLEN and A N T H O N Y A N T O N , E. I. du Pont de Nemours & Co., Inc., Wilmington, Del. Anal. Chem. 3 2 , 1 0 3 ( 1 9 6 0 )
Multicomponent mixtures are analyzed by ultraviolet spectrophotometry using an analytical curve-fitting tech nique. The experimental absorbancy curve is matched by an absorbancy curve calculated by combining the extinction curves of the individual components with selected weighting factors. Application is to mixtures containing ergosterol. J. C. STERNBERG, H. S. ST1LLO, and R. H. S C H W E N D E M A N , Michigan State University, East Lansing, Mich. Anal. Chem. 3 2 , 8 4 ( 1 9 6 0 )
Thermal Stability and Titrimetric Determination of Decaborane
Decaborane is quantitatively determined by a titrimetric procedure. The sample is oxidized with potassium iodate. The excess iodate is reacted with potassium iodide and the liberated iodine is titrated with sodium thiosulfate. The compound is also determined by dif ferential thermal analysis in air and helium. M. I. FAUTH and C. F. McNERNEY, U. S. N a v a l Propellant Plant, Indian H e a d , M d . Anal. Chem. 3 2 , 9 1 ( 1 9 6 0 )
Polarographic Determination of a-Methyl-DL-cystine
The substituted amino acid, α-methyl-DL-cystine, is determined by polarographic procedure in 0ΛΝ hydro chloric acid with thynol as the maximum suppressor. Factors related to concentrations, temperature, and pH are investigated. R. J. THIBERT and R. M. OTTENBRITE, Assumption University of Windsor, Windsor, Ontario, Canada Anal. Chem. 3 2 , 1 0 6 ( 1 9 6 0 )
Automatic Recording of Dissolved O x y g e n in Aqueous Systems containing Surface Active Agents
The dropping mercury polarograph was adapted for con tinuous recording of dissolved oxygen in an aeration column. The effect of surface active agents on electrode reaction kinetics was studied in this closed system which maintained a constant volume of solution being aerated. K. H. MANCY and D. A. O K U N , University of North Carolina, Chapel Hill, N. C. Anal. Chem. 3 2 , 1 0 8 ( 1 9 6 0 )
VOL. 32, NO. 1, JANUARY 1960
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BRIEFS Modifications Nitrogen
of
Kjeidahl
Digestion
for
Organic
The Kjeidahl digestion for organic nitrogen compounds is modified by replacing the salicylic acid-thiosulfate with sucrose. This permits reduction at much lower temperature. The addition of phosphoric acid in the sucrose-reducing system lends aid in determination of pyridine ring compounds. R. B. BRADSTREET, The Bradstreet Laboratories, C r a n f o r d , N . J. A n a l . Chem. 3 2 , 1 1 4 ( 1 9 6 0 )
Apparatus Fluorides
for
Pyrohydrolytic
Determination
Announcing—
5th Decennial Index to Chemical Abstracts
of
An efficient apparatus is designed for the pyrohydrolysis of about 30 mg. of fluoride in complex salts. Direct alkalimetric titration is used to determine the evolved hydrofluoric acid in the absence of intefering substances. Hydrofluoric acid is also determined by the thoron spectrophototnetric procedure. J. G . SURAK, D. J. FISHER, C. L. BURROS, a n d L. C. BATE, 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 , 1 1 7 ( 1 9 6 0 )
Determination of Niobium in the Parts Per Million Range in Rocks
The thiocyanate method is modified to increase its speci ficity and broaden its application. Many elements that interfere are separated by sodium hydroxide fusion and leach. Titanium interference is eliminated. Tolerance levels are recorded for a series of elements. Application is made in determining parts per million of niobium in granite rock.
A nineteen volume index to chemistry and chemical engineering for the years 1 9 4 7 to 1 9 5 6
Covering: 5 4 3 , 0 6 4 Abstracts of Papers 1 0 4 , 2 4 9 Abstracts of Patents
Keyed by: Authors Formulas Subjects Patent Numbers Organic Rings
F. S. GR1MALD1, U. S. G e o l o g i c a l Survey, W a s h i n g t o n 2 5 , D.C. A n a l . Chem. 3 2 , 1 1 9 ( 1 9 6 0 )
Use of Isonicotinic Acid Hydrazide (INH) as a Reagent for the Determination of Certain Flavonoids
Isonicotinic acid hydrazide reagent reacts with certain flavonoids to give an accurate, reproducible micromethod. Flavonoids are separated for identification and determination by paper chromatography. The complex formed is extracted from the paper and spectrophotometrically measured at 450 ηΐμ. C. D. HAWKER, H. W . MARGRAF, a n d Τ. Ε. WEICHSELBAUM, W a s h ington University School o f Medicine a n d Surgical Metabolism L a b o r a t o r y o f Barnes H o s p i t a l , St. Louis, M o . A n a l . Chem. 3 2 , 1 2 2 ( 1 9 6 0 )
Determination metric Method
of
Silicon
by
Distillation-Colori-
Microgram quantities of silicon are separated from plutonium and other metals by a volatilization procedure. Silicon tetrafluoride is quantitatively expelled from the sample solution in an all-platinum distillation vessel. The distillate is absorbed in a boric-molybdic acid solution in which the molybdenum blue color is de veloped.
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B. D. HOLT, A r g o n n e N a t i o n a l L a b o r a t o r y , Lemont, III. A n a l . Chem. 3 2 , 1 2 4 ( 1 9 6 0 )
V O L . 3 2 , N O . 1 , JANUARY 1 9 6 0
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