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Highlights of Articles in This Issue
Studies of Arenetricarbonylchromium Derivatives by Gas-Liquid Chromatography and Nuclear Magnetic Resonance
Application of Method of Maximum Posterior Probability to Estimation of Gas-Chromatographic Peak Parameters
This work describes the preparation of 13 derivatives of benzcnetricarbonylchromium, their analysis by gas chro matography and mass spectrometry, and their nmr spectra run either isothermally at different temperatures or at variable temperature.
Λ method capable of attaining the highest possible pre cision in the analysis of gas-chromatographic peaks is ap plied to an isothermal system employing a thermal con ductivity detector.
CATHERINE SEGARD, BERNARD ROQUES, CLAUDE POM MIER, and GEORGES GUIOCHON, Department of Chem istry, Ecole Polytechnique, Paris, France Anal. Chem., 43, 1146 (1971)
Anal. Chem., 43, 1184 (1971) Semiautomated, Specific Routine Serum Cholesterol Determination by Gas-Liquid Chromatography
Identification of New Steranes, Terpanes, and Branched Paraffins in Green River Shale by Combined Capillary Gas Chromatography and Mass Spectrometry Twenty-two new components have been identified in a gas chromatography—mass sepctrometry analysis of the Green Hiver Shale saturate hydrocarbon fraction. These include two tetracyclic and 11 tricyclic terpanes, two 5-/3-steranes, 5-a-pregnane, and some branched paraffins. E. J. GALLEGOS, Chevron Research Company, Richmond, Calif. 94802 Anal. Chem., 43, 1151 (1971) Preparation and Evaluation of Isocyanate-Based Polyimides as Liquid Phases for Gas Chromatography Polyimides designed for use as liquid phases in gas chroma tography were prepared by an isocyanate-anhydride reac tion. The polymers arc suitable for the preparation of hydrocarbons, steroids, and other "polar" molecules. R. G. MATHEWS, and R. D. SCHWARTZ, Research Engi neering and Development Department, Pennzoil United, Inc., Shreveport, La. 71102, and M. NOVOTNY and A. ZLATKIS, Chemistry Department, University of Houston, Houston, Texas 77004 Anal. Chem., 43, 1161 (1971) Relation between Structure and Retention Time of Sterols in Gas Chromatography The gas chromatographic relative retention times have been determined for 92 sterols and sterol acetates relative to cholesterol and cholesterol acetate, respectively. Rela tionship between structure and retention time is stressed. GLENN W. PATTERSON, Botany Department, of Maryland, College Park, Md. 20742
P. C. KELLY and W. E. HARRIS, Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada
University
A semiautomated gas—liquid chromatographic method for serum cholesterol was developed. This method has the equivalent accuracy of (he Abell-Kendall procedure and the capability of analyzing 40 samples per hour. J. L. DRISCOLL, D. AUBUCHON, M. DESCOTEAUX, and H. F. MARTIN, Pathology Department, Rhode Island Hos pital, Providence, R. I. Anal. Chem., 43, 1196 (1971) Thermodynamics of Solutions with Liquid Crystal Solvents. Surface Effects with Cholesteric Compounds DSC transition temperatures and enthalpies and GLC reten tion data are found to be independent of liquid crystal film thickness for cholestcryl myristatc, cholestcryl chloride, and a mixture of the two. JOEL M. SCHNUR and DANIEL E. MARTIRE, Department of Chemistry, Georgetown University, Washington, D. C. 20007 Anal. Chem., 43, 1201 (1971) Determination of Blood in Dried Formalin-Fixed Lung Tissue. Spectrophotometric Method Involving Pyrrole Residues of the Porphyrin Ring Dried formalin-fixed lung tissue contains blood which can not be determined by available methods. The effect of formalin is removed by a phenol digestion. Hydrolysis in hydrioflic acid converts the heme group to pyrrole frag ments which give a color with Ehrlich's reagent. IMANUEL BERGMAN and ROY LOXLEY, Safety in Mines Research Establishment, Department of Trade and In dustry, Sheffield S3 7HQ, England Anal. Chem., 43, 1204 (1971)
Anal. Chem., 43, 1165 (1971) Estimation of Chromatographic Peaks with Particular Consideration of Effects of Base-Line Noise
Direct Potentiometric Measurement of Hydrogen Ion Concentrations in Sodium Chloride Solutions of Fixed Ionic Strength
A method of estimating the parameters of a peak in the presence of base-line noise is presented. This method ap proaches the highest precision possible for a given gaschromatographic system.
The cell glass electrode//H* (aq)/calomel elec(rode has been calibrated against buffer solutions of known [H + ] to give pH(measured) = 0.995 p [ H + ] + 0.088 at / = 0.04 to 0.20Λ/, NaCl medium.
P. C. KELLY and W. E. HARRIS, Department of Chem istry, University of Alberta, Edmonton 7, Alberta, Canada
G. R. HEDW/G and H. K. J. POWELL, Department of Chem istry, University of Canterbury, Christchurch, New Zealand.
Anal. Chem., 43, 1170 (1971)
Anal. Chem., 43, 1206 (1971) ANALYTICAL CHEMISTRY, VOL. 43, NO. 10, AUGUST 1971
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AC BRIEFS Determination of Uranium(IV), Uranium(Vf), and Total Uranium in Phosphoric Acid Process Solutions by Tri-n-Octylamine Extraction and Polarography
Use of the Nitrous Oxide-Acetylene Flame for Determination of Arsenic and Selenium by Atomic Absorption Spectrometry
By TOA extraction, TJ(IV) is separated from TJ(VI) in mixtures containing 0.05 to 0.2 m g / m l total TJ in phosphate rock solutions. Uranium in the aqueous back extract is determined by polarography. Extraction of TJ(IV) is prevented by H3PO.1 present in the aqueous phase.
Arsenic and selenium are determined by AAS using the conventional- or nitrogen-separated nitrous oxide—acetylene flame. Lower flame background absorbance, improved detection limits, and greater freedom from interference compared to other flames are observed.
ISAAC HODARA and ISAAC BALOUKA, Israel Atomic Energy Commission, Nuclear Research Centre—Negev, Beersheva, Israel
G. F. KIRKBRIGHT and LESLIE RANSON, Chemistry Department, Imperial College, London S.W.7., U.K. Anal. Chem., 43, 1238 (1971)
Anal. Chem., 43, 1213 (1971) Utilization of the Matrix as a Standard in Trace Analysis by Neutron Activation Analysis. Analysis of Cadmium-Doped Sodium Chloride Crystals A method has been developed which utilizes a matrix component as a standard in Neutron Activation Analysis. Cadmium-doped NaCl crystals have been analyzed with a relative standard deviation of 4.1%. M. HEURTEBISE and J. A. LUBKOWITZ, Quimica Nuclear, Instituto Venezolano de Investigaciones Cientificas, Apartado, 1827, Caracas, Venezuela
Determination of Carbon-14, Hydrogen-3, and Sulfur-35 in Rubber Vulcanizates. A New Degradation Method for Liquid Scintillation Counting An in-vial degradation method has been developed for simultaneous preparation of a large number of rubber samples containing M C, 3 H, or 3SS for liquid scintillation counting. DAV/D A. CHAPMAN and CARL R. PARKS, Research Division, The Goodyear Tire & Rubber Company, Akron, Ohio 44316 Anal. Chem., 43, 1242 (1971)
Anal. Chem., 43, 1218 (1971) Structures of Two Five-Coordinated Metal Chelates of 2-Methyl-8-Quinolinol The ligand, 2-methyl-8-quinolinol, forms bis complexes with V0 2 + and GaCl2*. The structures of the resulting five coordinated chelates have been determined by single-crystal X-ray techniques. MOTOO SHIRO and QUINTUS FERNANDO, Department of Chemistry, University of Arizona, Tucson, Ariz.
Carbon-13 Nuclear Magnetic Resonance Spectrometry. Chemical Shifts for the Paraffins through C, Carbon-13 nmr chemical shifts arc reported for the paraffins through G.. An improved set of 13C chemical shift prediction parameters for the paraffins is given. L. P. LINDEMAN and J. Q. ADAMS, Chevron Research Company, Richmond, Calif. 94802 Anal. Chem., 43, 1245
(1971)
Anal. Chem., 43, 1222 (1971) Potential Impulse Method, Operational Immittance, and the Study' of Electrode Processes
Use of Anion Exchange Resin-Loaded Paper in the Determination of Trace Mercury in Water by Neutron Activation Analysis
The potential impulse method is examined as a new technique for studying processes.
The total Hg content of water can lie determined to a detection limit of 0.005 MK and normal accuracies of ±3Çr
RONALD L. BIRKE, Department of Chemistry, of South Florida, Tampa, Fla. 33620
D. £. BECKNELL, R. H. MARSH, and WILLIAM ALLIE, Jr., Scientific Research Staff, Ford Motor Company, Dearborn, Mich. Anal. Chem., 43, 1230 (1971)
Ion Association between Indicators and Indifferent Electrolytes
University
Anal. Chem., 43, 1253 (1971)
Theory of Continuous Variations Plots and a New Method for Spectrophotometric Determination of Extraction and Formation Constants
Oolorimctric measurements of the influence of indifferent electrolytes on (lie dissociation of indicators give evidence for ion associations between the cation of the electrolyte and the anion of the indicator.
A new method utilizing the continuous variations and normalized absorbance concepts has been developed for the spectrophotometric determination of extraction and formation constants. The proposed method has been applied to the determination of extraction constants for six metal chelates.
MICHEL de VYLDER and WILFRIED RIGOLE, Laboratory of Physical Chemistry, University of Ghent, Belgium
WERNER LIKUSSAR and D. F. BOLTZ, Department of Chemistry, Wayne State University, Detroit, Mich. 48202
Anal. Chem. 43, 1234 (1971)
Anal. Chem., 43, 1265 (1971) ANALYTICAL CHEMISTRY, VOL. 43, NO. 10, AUGUST 1971
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Indirect D e t e r m i n a t i o n of T i t a n i u m by Atomic Absorption S p e c t r o m e t r y
S p e c t r o p h o t o m e t r i c D e t e r m i n a t i o n of Extraction Constants for Certain M e t a l 1-Pyrrolidinecarbodithioates
The rxtraclion constants for the 1-pyrrolidinccarbodithioate complexes of copper(II), cobalt(II), cadmium(Il), zinc(II), hisnmtli(III). and galliuni(III) have been determined by a modified continuous variations spectrophotometric method. W. LIKUSSAR and D. F. BOLTZ, Department of Wayne State University, Detroit, Mich. 48202 Anal. Chem.,
A method based on the suppression of the absorbance of strontium by titanium in the presence of oxalate ion has been developed for determination of traces of titanium. Its sensitivity is 0.15 Mg/ml of titanium. C. L. CHAKRABART/ and MOHAN KATYAL, Department of Chemistry, Car/eton University, Ottawa, Ontario, Canada
Chemistry,
43, 1273
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Anal. Chem., 43, 1302
(1971)
(1971) Fluorescence Spectra of
I n s t r u m e n t a l - C o m p u t e r System for Analysis of M u l t i c o m p o n e n t Organic M i x t u r e s
3H-[l,2,4]Thiadiazolo[4,3-3]pyridines,
A method for the analysis of multicomponent, organic mixtures in aqueous solutions is describee!. The technique is based on pyrolysis, followed by gas chromatographic separation of the produced fragments.
The fluorescence associated with the τ —» w* transition of a series of substituted 3//-[l,2,4]-thiadiazolo[4,3-n]pyridines was studied in a variety of media at room tempera ture and at 77°K with a view toward a possible trace signal system.
IHOR LYSYJ and PETER R. NEWTON, Rocketdyne, Division of North American Rockwell Corporation, Field Laboratory, Athens, Ga., and WILLIAM J. TAYLOR, Environmental Protection Agency, Water Quality Office, Athens, Ga. Anal. Chem., 43, 1277 (1971) C o m p u t e r Controlled Fourier T r a n s f o r m N u c l e a r M a g n e t i c Resonance S y s t e m for C a r b o n - 1 3 and Phosphorus-31 Spectrometry
R. J. CUSHLEY, D. R. A N D E R S O N , and S. R. L/PSKY, Section of Physical Sciences, Yale University School of Medicine, New Haven, Conn. 06510 43, 1281
(1971)
C o m p u t e r Applications in t h e C h e m i s t r y L a b o r a t o r y A Survey
A survey of the laboratory applications of digital computers in chemistry is presented in this paper. S. P. PERONE, Department of versity, Lafayette, Ind. 47907
Chemistry,
Anal. Chem.,
Purdue
43, 1288
Uni(1971)
Notes Evaluation of preferential quenching of fluorescence of spormidinc-o-pht.haldialdehyde derivative relative to fluorescence quenching of histaminc-o-phthaldialdchyde by haloNaCI (1.0Λ/) causes 20% and 93
