A C BRIEFS Highlights of Articles in This Issue
Ligand Exchange Chromatography of Amphetamine Drugs Amphetamine and related compounds were separated by chromatography on columns of polymethacrylate-type cat ion-exchange resins loaded with metal ions, using as eluents solutions of ammonia in aqueous alcohols. CECILIA M. DE HERNANDEZ and HAROLD F. WALTON, University of Colorado, Boulder, Colo. 80302 Anal. Chem., 44, 890 (1972) Gas Chromatographic Analysis of Complex Deuterated and Tritiated Mixtures with Packed Columns Mixtures of deuterated and tritiated ethanes, propanes, and butanes differing by one or two mass units are effec tively separated with high efficiency packed adsorption col umns. Λ critical evaluation of the possibilities of this tech nique is also reported. FABRIZIO BRUNER, PAOLO CICCIOLI, and ANTONIO DI CORCIA, Laboratorio Inquinamento Atmosferico del C.N.R. and Istituto di Chimïca Analitica dell'Universita, 00185 Roma, Italy Anal. Chem., 44, 894 (1972) Quantitative Determination of Fluorenes in Cigarette Smoke and Their Formation by Pyrosynthesis Fluorene, the five methylfluoren.es, and several dimethylfluorenes were isolated from the mainstream smoke of cigarettes, identified, and quantitatively determined (800900 ng/cigarette). Experimental data support the hypothesis that these hydrocarbons are partially formed via the Diels-Alder additions of indenes with volatile dienes. DIETRICH HOFFMANN and GUNTER RATHKAMP, Division of Environmental Carcinogenesis, American Health Foundation, New York, N.Y. 10021 Anal. Chem., 44, 899 (1972) Iodine in Acetic A c i d - Α Specific Analytical Reagent for the Cyclization of Aryl 2-Propynylcarboxamides Aryl-2-propynylcarboxamides can be quantitatively deter mined using iodine in acetic acid. The reaction is specific and involves a cyclization mechanism to give oxazolinc. Titration of the unreacted iodine gives the purity of the compound. J. A. RAIHLE, L. J. SCHOMMER, and D. C. WIMER, Ab bott Laboratories, North Chicago, III. 60064 Anal. Chem., 44, 905 (1972) Microdetermination of the Nitro and Nitroso Groups in Aromatic Compounds by Reduction with Iron(ll) in Acidic and Alkaline Media Methods for microdetermination of the nitro and nitroso groups in aromatic compounds by reduction with iron (II) in strong acidic and alkaline media have been developed. W. /. AWAD, S. S. M. Hassan, and M. T. M. ZAKI, Microanalytical Research Laboratory, Department of Chemis try, Faculty of Science, Ain Shams University Cairo, Egypt Anal. Chem., 44, 911 (1972)
Separation of High-Boiling Petroleum Distillates Using Gradient Elution Through Dual-Packed (Silica Gel-Alumina Gel) Adsorption Columns This newly developed liquid-solid chromatographic proce dure separates high-boiling petroleum distillates into four important compound type concentrates: saturates, monoaromatics, diaromaties, and polyaromatics-polar. Such sep arations greatly simplify subsequent separation and char acterization studies. D. £. H/RSCH, R. L. HOPKINS, H. J. COLEMAN, F. O. COTTON, and C. J. THOMPSON, Bartlesville Energy Re search Center, Bureau of Mines, U.S. Department of the Interior, Bartlesville, Okla. 74003 Anal. Chem., 44, 915 (1972) Simultaneous Determination of Bromine and Chlorine with Methyl Orange Gaseous bromine and chlorine mixtures at concentrations up (o 5 itcq/liter in nitrogen were determined spectrophotometrically by reaction with aqueous methyl orange solutions. H. A. LAITINEN and KENNETH W. BOYER, Department of Chemistry, University of Illinois, Urbana, III. 61801 Anal. Chem., 44, 920 (1972) Determination of Alkylbenzenesulfonate and Alkylsulfate Homologs, after Electrophoretic Separation Using Aqueous Dioxane Agarose Gels p-(l-Elliyldecyl)benzenesulfonate (;>-3-12-s) sulfate (1-12-s) were recovered from aqueous ose gels after electrophoresis. A recovery of with a relative standard deviation of 0.6 per tained for 7>3-12-s. A relative error of 1.0 obtained for the determination of /)-3-12-s in taining 10,14 and 10,11 homologs.
and dodecyldioxane/agarSS.4 per cent cent was ob per cent was mixtures con
JOHN R. BODENMILLER and HOWARD W. LATZ, Depart ment of Chemistry, Ohio University, Athens, Ohio 45701 Anal. Chem., 44, 926 (1972) Factors Affecting the Use of a Nondispersive System for Atomic Fluorescence Flame Spectrometry A nondispersive atomic fluorescence system is described and considerations affecting the signal-to-noisc ratio of atomic fluorescence with line excitation sources are discussed. T. J. VICKERS, P. J. SLEVIN, V. /. MUSCAT, and L. T. FA RIAS, Department of Chemistry, Florida State University, Tallahassee, Fla. 32306 Anal. Chem., 44, 930 (1972) Comparison of Atomic Fluorescence with Atomic Absorption as an Analytical Technique Two instrumental systems for atomic fluorescence were de signed, tested, and compared to atomic absorption for de tection limits, linearity, and interferences. WILLIAM B. BARNETT and HERBERT L. KAHN, The Perkin-Elmer Corporation, Norwalk, Conn. 06856 Anal. Chem., 44, 935 (1972) ANALYTICAL CHEMISTRY VOL. 44, NO. 6, MAY 1972
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AC Factors Affecting the Use of External Standards for Spark Source Mass Spectrometry The use of standard electrodes for spark source mass spec trometry has been studied with respect to effect of electrode positioning, associated precision, and application to real analyses. W. W. HARRISON and G. G. CLEMENA, Department of Chemistry, University of Virginia, Charlottesville, Va. 22901 Anal. Chem., 44, 940 (1972) Digital Data Handling of Spectra Utilizing Fourier Transformations Smoothing, differentiation, and resolution enhancement of spectra utilizing Fourier transformations is described. In cluded is a discussion of the distribution of spectral in formation in the Fourier domain. GARY HORL/CK, Department of Chemistry, University of Alberta, Edmonton, Alberta Anal. Chem., 44, 943 (1972) Pulsed Source-Time Resolved Phosphorimetry A pulsed-sourcc phosphorimeter for time resolution phos phorimetry is used to resolve several multicomponent mix tures of spectrally similar organic molecules. R. P. FISHER and J. D. WINEFORDNER, Department of Chemistry, University of Florida, Gainesville, Fla. 32601 Anal. Chem., 44, 948 (1972)
BRIEFS
Analytical Applications of Ion-Molecule Reactions. Identification of C S H 1 0 Isomers by Ion Cyclotron Resonance Spectrometry The ion-molecule reactions of the 1,3-butadiene molecular ion and various isomeric C5H10 compounds have been in vestigated by ion cyclotron resonance spectrometry. Sig nificant differences were observed which allow complete identification of the isomers. MICHAEL L. GROSS, PING-HUANG LIN, and STANLEY J. FRANKLIN, Department of Chemistry, University of Ne braska-Lincoln, Lincoln, Neb. 68508 Anal. Chem., 44, 974 (1972) Use of Electron Spin Resonance to Characterize the Vanadium(IV)-Sulfur Species in Petroleum Electron spin resonance spectroscopy has been proposed as a potentially useful method of identifying vanadium (IV) environments in petroleum. Data on fractions of petro leum residuals have revealed differences in the vana dium (IV) ESR parameters. F. E. DICKSON, C. J. KUNESH, E. L. McGINNIS, and LEOΝ IDAS PETRAKIS, Gulf Research & Development Com pany, Pittsburgh, Pa. 15230 Anal. Chem., 44, 978 (1972) Pulsed Nuclear Magnetic Resonance Measurement of Relaxation Times in Ion-Exchange Resins
Determination of Trace Amounts of Chromium(lll) Using Chemiluminescence Analysis
Transverse and longitudinal proton relaxation times are measured as a function of cross-linking and water con tent. The environment for water protons seems to be water-like above 6 waters per site, but structured below.
Trace Cr(III) in natural waters is determined by measur ing the extent to which it catalyzes light emission from the luminol oxidation.
W. J. BLAEDEL, L. E. BROWER, T. L. JAMES, and J. H. NOGGLE, Department of Chemistry, University of Wiscon sin, Mad/son, Wis. 53706
W. RUDOLF SEITZ, Southeast Water Laboratory, Environ mental Protection Agency, Athens, Ga. 30601, and WAL LACE W. SUYDAM and DAVID M. HERCULES, Depart ment of Chemistry, University of Georgia, Athens, Ga. 30601
Anal. Chem., 44, 982 (1972)
Anal. Chem., 44, 957 (1972) Influence of Solvent Matrix upon Phosphorescence Signals
Self-Balancing Bridge for Differential Capacitance Measurements A self-balancing capacitance bridge is described which will determine the capacitance of mercury electrodes in the range of 0.2 to 2.0 microfarads with an accuracy of ± 1 % .
Low weight per cent methanol and/or sodium iodide, so dium bromide, or sodium chloride aqueous solutions freeze to snows and can be used as solvents for phosphorimetry.
DALE H. CHIDESTER and RONALD R. SCHROEDER, De partment of Chemistry, Wayne State University, Detroit, Mich. Anal. Chem., 44, 985 (1972)
R. J. LUKASIEWICZ, J. J. MOUSA, and J. D. WINEFORD NER, Department of Chemistry, University of Florida, Gainesville, Fla. 32601 Anal. Chem., 44, 963 (1972)
Differential Voltammetric Scanning Thermometry of Tenth Formal Formaldehyde Solution in Formal Perchloric Acid
Auger Lines in X-Ray Photoelectron Spectrometry A survey has been made of the Auger lines from all ele ments, induced by ΑΙ Κα radiation. Auger electrons in three series, from forty-four of the elements, are detectable. C. D. WAGNER, Shell Development Company, Emeryville, Calif. 94608. Anal. Chem., 44, 967 (1972)
Single electrode reaction heats were measured using DTA with cyclic voltammetry. Preliminary evaluation methods for ovcrpotential heating are illustrated. Surface poisons and reactions are discussed relative to non-electrochemical thermal events. BRUCE B. GRAVES, Department of Chemistry, Eastern Michigan University, Ypsilanti, Mich. 48197 Anal. Chem., 44, 993 (1972) ANALYTICAL CHEMISTRY, VOL. 44, NO. 6, MAY 1972
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Electrochemical Studies of meso-Tetra(4-N-Methylpyridyl)porphin in Acid Solution The electrochemical reduction of meso-tetra(4-iV-methylpyridyDporphin tetraiodide in acid solution was investi gated. Dissociation constants and optical spectra for vari ous porphyrin oxidation states are presented along with mechanisms and postulated structures. BRUCE P. NERI and GEORGE S. WILSON, Department Chemistry, University of Arizona, Tucson, Ariz. 85721
of
Anal. Chem., 44, 1002 (1972)
Interpretation of Isopotential Points. The Common Intersection in Families of Current-Potential Curves The detailed theory for the occurrence of isopotential points, the λ-oltammetric analogy of isobestic points, is de veloped. These theoretical results are used to interpret both new and previously reported data. D. F. UNTEREKER and STANLEY BRUCKENSTE1N, Chem istry Department, State University of New York at Buf falo, Buffalo, N.Y. 14214 Anal. Chem., 44, 1009
(1972)
A Rapid, Sensitive Method for Calibration of Permeation Devices A rapid weighing technique employing a recording microbalance is used for calibration of permeation tubes. This technique has significantly reduced the time required for calibration of these devices. LARRY J. PURDUE and RICHARD J. THOMPSON, Environ mental Protection Agency, Research Triangle Park, N.C. 27711 Anal. Chem., 44, 1034 (1972) Systematic Studies on the Breakdown of p,p-DDT in Tobacco Smokes. Investigations into the Presence of Methyl Chloride, Dichloromethane, and Chloroform in Tobacco Smokes Pesticide free tobacco samples fortified with p , j / - D D T were smoked without interruption and the smoke condensates ex amined for the presence of methyl chloride, dichlorometh ane, and chloroform. N. M. CHOPRA and LARRY R. SHERMAN, Department of Chemistry, North Carolina Agricultural and Technical State University, Greensboro, N.C. 27411 Anal. Chem., 44, 1036 (1972)
Radio Frequency Spectral Emission Discharge Detector for Fixed Gases
Standard Solution for Redox Potential Measurements
A radio frequency spectral emission detector was developed for measurement of trace concentrations of fixed gases in helium.
A solution for checking redox systems may be prepared from ferrous and ferric salts in sulfuric acid. The poten tial is +475 mV vs. the Ag,AgCl,KCl(4M) reference elec trode at 250 "C.
L. E. BOOS, JR., and J. D. WINEFORDNER, Department of Chemistry, University of Florida, Gainesville, Fla. 32601 Anal. Chem., 44, 1020 (1972)
Automated Vacuum Fusion Apparatus A computer has been interfaced to a specially constructed vacuum fusion apparatus to form a completely automated system for the determination of H 2 , O2, and N2 in metals. J. W. FRAZER, J. W. FISCHER, C. J. MORRIS, R. W. CRAW FORD, and E. R. FISHER, Lawrence Livermore Lab oratory, University of California, Livermore, Calif., 94550 Anal. Chem., 44, 1027 (1972)
TRUMAN S. LIGHT, Research Center, The Foxboro Com pany, Foxboro, Mass. 02035 Anal. Chem., 44, 1038 (1972) Determination of Bis(2-Chloroethyl)Sulfide in a Dawson Apparatus by Gas Chromatography Bis (2-chloroethyl) sulfide was determined quantitatively by gas liquid chromatography and thereby more efficiently with similar accuracy compared to the usual colorimetric method. The minimum detectable amount was 0.005 microgram. RICHARD L. ERICKSON, R/CHARD N. ARD H. BROWN, and HUBERTINA D. and Personal Life Support Equipment Army Natick Laboratories, Natick, Mass.
MACNAIR, RICH HOGAN, Clothing Laboratory, U.S. 01760
Anal. Chem., 44, 1040 (1972) Turbidimetry via Parallel Photometric Analysis. Determination of Sulfate
Determination of Tin and Antimony in Type Metal Using Atomic Absorption Spectrophotometry
The parallel photometric analysis technique is shown to overcome many of the inherent difficulties in turbidimetry. Two exemplary sulfate procedures are studied in detail and found (o possess precision, accuracy, sensitivity, and speed comparable to spectrophotometric procedures in general.
This procedure dissolves the sample in a fluoboric-^iitric acid mixture. Its standard deviation for Sn is 0.05%; for Sb, 0.08%; and for Cu, 0.0002%. Results agree with those of standard wet methods to ±0.20%.
R. L. COLEMAN, W. D. SHULTS, M. T. KELLEY, and J. A. DEAN, Analytical Chemistry Division, Oak Ridge National Laboratory, Oak Ridge, Tenn. 37830
JOSEPH U. GOUIN, JANET L. HOLT, and RALPH E. MIL LER, Tests and Technical Control Service, U.S. Govern ment Printing Office, Washington, D.C.
Anal. Chem., 44, 1031 (1972)
Anal. Chem., 44, 1042 (1972) ANALYTICAL CHEMISTRY, VOL. 44, NO. 6, MAY 1972
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AC BRIEFS Phototautomerism in the Lowest Excited Singlet State of 4-Methylumbelliferone
Rapid Characterization of Salmonella Organisms by Means of Pyrolysis-Gas-Liquid Chromatography
The fluorescence of 4-methylumbelliferone in dilute acid originates from an excited zwitterion formed by tautomerism of the excited neutral species.
Fifty-four coded Salmonella samples were examined by the pyrolysis—gas-liquid chromatography (PLGC) technique. After the characteristic P G L C peaks have been identified, a more direct, determinitive classification and a more rapid identification of cells can be foreseen.
G. J. YAKATAN, R. J. JUNEAU, and S. G. SCHULMAN, College of Pharmacy, University of Florida, Gainesville, Fla. 32601 Anal. Chem., 44, 1044 (1972)
Direct Steady State Calibration of a Flame Ionization Detector Calibration curves for ?t-paraffm hydrocarbons ethane through H-decane were linear from 10"11 to 10* mole/sec and were fourth order polynomials from 10"s to 5 X 10"7 mole/sec. GRANT F. CARRUTH and RIKI KOBAYASHI, Department of Chemical Engineering, Rice University, Houston, Texas 77001 Anal. Chem., 44, 1047 (1972)
Simultaneous Determination of Sample Concentration and Reagent Blank A method has been developed for the simultaneous determination of reagent blank and trace sample content. The method has been applied to iron and silica determinations in ultrapure water and reagent grade chemicals. MAX B. KLOSTER and CLIFFORD C. HACH, Water Analysis Research Laboratory, Hach Chemical Company, Ames, Iowa 50010 Anal. Chem., 44, 1061 (1972) Improved Tissue Solubilization for Atomic Absorption
Sensitivity of Detection of the Elements by Photoelectron Spectrometry The atomic sensitivities in X-ray photoelectron spectrometry have been determined for the Varian spectrometer, The Is line of fluorine is used as the standard. C. D. WAGNER, Shell Development Company, Emeryville, Calif. Anal. Chem., 44, 1050 (1972)
A method, that is simpler and more reproducible than established methods, is presented for the preparation of a small tissue sample (50.0—100.0 mg) for atomic absorption. ANDRE J. JACKSON, LESLIE M. MICHAEL, and HERBERT J. SCHUMACHER, Department of Environmental Health, University of Cincinnati, College of Medicine, Cincinnati, Ohio 45219 Anal. Chem., 44, 1064 (1972) Application of Multiple Internal Reflection Spectrometry to Aircraft Materials Evaluation
Detection of Chlorine on Aluminum by Means of Nuclear Reactions Thin chlorine films on aluminum substrates have been delected using eharged-particlc-induccd nuclear reactions. The fastest, most convenient method is based on the detection of backseattcred 4 He ions. A. R. KNUDSON and K. L. DUNNING, Laboratory, Washington, D.C. 20390
E. J. REINER, JUDY J. HICKS, MARY M. BALL, and WILLIAM J. MARTIN, Microbial Chemistry Laboratory, Center for Disease Control, Public Health Service, U.S. Department of Health, Education, and Welfare, Atlanta, Ga. 30333 Anal. Chem., 44, 1058 (1972)
Naval Research
Multiple internal reflectance spectromctric methods capable of defining the bulk composition of the test specimen are described. Methods applicable to silicones, polyesters, urethancs, and advanced composite materials are discussed. T. T. BARTELS, Engineering Laboratories, craft Company, St. Louis, Mo. 63166
McDonnell Air-
Anal. Chem., 44, 1065 (1972)
Anal. Chem., 44, 1053 (1972) Determination of Fluorine and Bromine in Halogenated Herbicide Residues in Soil by Spark Source Mass Spectrometry Infrared Study in Potassium Bromide Disks of the Stability and Hydrolysis of Aromatic Polyurethane Foams The stability, hydrolysis, and amine reactions of unreacted isocyanate in polyurethane foams were determined by infrared in a KBr disk and found to have an activation energy of 7.8 ± 0.6 kcal/mole. ALBERT S. TOMPA, Fleet Support Department, Ordnance Station, Indian Head, Md. 20640
Naval
Anal. Chem., 44, 1056 (1972)
Samples, with concentrations of Br and F down to ppb levels and containing organic herbicides, are extracted from the soil, combusted, and determined by spark source mass spectrometric analysis of their respective halogen. Precision is normally about ± 2 5 % . S. C. TONG, Research and Development Laboratories, Corning Glass Works, Corning, N.Y. 14830, and W. H. GUTENMANN, L. E. ST. JOHN, JR., and D. J. LISK, Pesticide Residue Laboratory, Cornell University, Ithaca, N.Y. 14850 Anal. Chem., 44, 1069 (1972) ANALYTICAL CHEMISTRY, VOL. 44, NO. 6, MAY 1972
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AC Comparison of Cell Extraction Procedures for Use with High Pressure Liquid Chromatography Procedures for preparing samples for high pressure liquid chromatography were investigated. The use of trichloracetic acid followed by neutralization with T R I S is recommended because of simplicity, rapidity, and stability during storage. P. R. BROWN and R. P. MIECH, Section of Biochemical Pharmacology, Division of Biological and Medical Sci ences, Brown University, Providence, R.I. 02912 Anal. Chem., 44, 1072 (1972)
BRIEFS
Simple Method for Routine Detection of Residues of Diethylstilbestrol (DES) in Meat Contamination at Levels as Low as One Part per Billion The method consists of extraction utilizing acetonitrile : water (9:1), removal of contaminating tissue constituents from the extracted D E S with the aid of immiscible solvent systems, and detection of the extracted D E S by electron capture gas chromatography. WALTER G. SMITH and EDWARD E. McNEIL, Animal Pa thology Division, Health of Animals Branch, Canadian De partment of Agriculture, Animal Diseases Research Insti tute, Huli, Quebec, Canada
An Approach to the Characterization of IsocyanateTerminated Prepolymers
Anal. Chem., 44, 1084 (1972)
This procedure involves a spectroscopic examination, a measure of molecular weight and equivalent weight, a de termination of the functionality of the prepolymer by gel point measurements, and the hydrolysis and identification of the prepolymer components. MERVYN B. JACKSON, Division of Protein Chemistry, CSIRO, Parkville (Melbourne), Victoria 3052, Australia, and D. H. SOLOMON, Division of Applied Chemistry, CSIRO, Fisherman's Bend (Melbourne), Victoria 3207, Australia Anal. Chem., 44, 1074 (1972) Determination of Oxygen in Aluminum by Helium-3 Activation Oxygen in aluminum can be determined by activation with He particles of 8 to 12 MeV. 0.2 ppm of oxygen in electrolytically refined Al and less than 0.05 ppm in zone re fined Λ1 was found.
Application of Radioactivation to the Sequential Separation of Antimony, Cadmium, Chromium, Cobalt, Iron, Tin, and Zinc from Aluminum and Lead by Ion-Exchange Chromatography A radioanalytical separation scheme for multielement de termination in aluminium and lead by anion-exchange chromatography is presented. New distribution coefficient values are included. THARWAT Z. BISHAY, Scottish Research Reactor Centre, East Kilbride, Glasgow, Scotland, G.B. Anal. Chem., 44, 1087 (1972) Highly Selective and Sensitive Spectrophotometric Determination of Iron(ll) and Cobalt(lll) with 4-(2-Pyridylazo)resorcinol(PAR)
s
BERNARD VIALATTE, Laboratoire Pierre Sue (C.N.R.S.)Cen/Saclay B.P. no 2, Gif sur Yvette 91 France, and GILLES REVEL, Centre d'Etudes de Chimie Métallurgique (C.N.R.S.), 15 rue G. Urbain, Vitry, 94 France Anal. Chem., 44, 1077
In boiling borate buffer containing E D T A , the color reac tion of PAR with metals becomes highly specific for iron(II) and cobalt(II). Using this reaction, spectrophotometric methods for iron and cobalt are proposed. TAKAO YOTSUYANAGI, RYUJI YAMASHITA, and KAZUO AOMURA, Laboratory of Analytical Chemistry, Faculty of Engineering, Hokkaido University, Sapporo-shi, 060, Japan
(1972)
New Method for Determination of 21-Hydroxy Corticosteroids 21-Hydroxy corticosteroids are determined spectrophotometrically after treatment with cuprie acetate followed by o-phenylenc diamine (or its 4.5-dimethyl derivative) as the stable quinoxaline derivative even in the presence of 500fold quantity of 21-acyloxy derivatives. SANDER GOROG and GABOR SZEPESI, Chemical Works G. Richter, Budapest 10, Hungary Anal. Chem., 44, 1079 (1972) Separation of Cadmium(ll) from Zinc(ll) and Other Metal Ions on a Cadmium Selective Exchanger: Titanium Selenite Tracer quantities of cadmium (70-1000 μg) have been sepa rated from much larger quantities of zinc (50—2000 /ig) and vice-versa on titanium selenite columns. Cd has also been separated from Ni, Co, Mn, Ca, Mg, and Al. MOHSIN QURESHI, RAJENDRA KUMAR, and H. S. RATHORE, Department of Chemistry, Aligarh Muslim Uni versity, Aligarh, U. P., India Anal. Chem., 44, 1081 (1972)
Anal. Chem., 44, 1091 (1972) Loss of Mercury from Water during Storage Losses, up to 100% in certain instances, were observed in dilute aqueous solutions of mercury (0.05 mg/1.) stored in polyethylene bottles. ROBERT V. COYNE and JAMES A. COLLINS, U.S. Air Force Environmental Health Laboratory, McClellan Air Force Base, Calif. 95652 Anal. Chem., 44, 1093 (1972)
Correspondence Conductometric Analysis of Oleum R. T. REWICK and M. P. DOLDER, Stanford Research In stitute, Inorganic-Physical Chemistry Group, Menlo Park, Calif. 94025 Anal. Chem., 44, 1096 (1972) Continuous Variations Curves and Complex Stoichiometry G. F. ATKINSON, Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada Anal. Chem., 44, 1098 (1972) ANALYTICAL CHEMISTRY, VOL. 44, NO. 6, MAY 1972
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A C BRIEFS
Exciting and timely subjects... with a publication to match:
Sulfate Ion-Selective Membrane Electrode G. A. RECHN1TZ, G. H. FRICKE, and M. S. MOHAN, Chem istry Department, State University of New York at Buffalo, Buffalo, ΛΙ.Υ. 14214 Anal. Chem., 44, 1098 (1972)
Aids for Analytical Chemists Reduction in Secondary Ion Fogging on Photographic Plates Used in Mass Spectrography J. B. CLEGG, Mullard Surrey, England
Research Laboratories,
The Journal of Agricultural and Food Chemistry
Redhill,
Anal. Chem., 44, 1100 (1972) Sampling Gases from a Hostile Environment ANDREW E. O'KEEFFE, Division of Chemistry and Physics, Office of Research and Monitoring, Environmental Protec tion Agency, National Environmental Research Center, Re search Triangle Park, N.C. 27711 Anal. Chem., 44, 1102 (1972) Volume Flowmeter for Gases of Variable Viscosity or Thermal Conductivity J. F. PARCHER and C. L. HUSSEY, Department of Chem istry, The University of Mississippi, University, Miss. 38677 Anal. Chem., 44, 1102 (1972) Conductivity Cell Apparatus for Continuous Measurement of Sulfur Dioxide Concentrations between 4 0 ppm and 1 Per Cent H. RICHARD BEARD, Salt Lake City Metallurgy Research Center, Bureau of Mines, U.S. Department of the Interior, Salt Lake City, Utah Anal. Chem., 44, 1104 (1972)
W i t h the world's nutritional crisis fast be coming a reality, more and more attention is being focused on these critical fields of chemistry. Pesticides (their mode of action and resi due analysis), the chemistry and identity of flavors and the nature and identity of additives, are all regularly discussed in the pages of JAFC. A m o n g the other subjects covered are the identity and metabolic rate of f o o d toxi cants, plant nutrients and regulators and chem istry of food processing. If you are a chemist—chemical engineer— a g r o n o m i s t — e n t o m o l o g i s t — n u t r i t i o n i s t — or are just interested in the broad fields of agri cultural and food processing chemistry—you'll find this journal a most valuable and informa tive publication. Start your o w n personal subscription by completing and returning the form below.
A Cell for Dielectrometric Titrations ROBERT MEGARGLE and GUSTAF FORSBERG, Depart ment of Chemistry, University of Missouri, Columbia, Mo. 65201 Anal. Chem., 44, 1105 (1972) Sample Injection Port for High Pressure Chromatography BRIAN PEARCE and W. LI. THOMAS, The British Petrol eum Company Limited, BP Research Centre, Chertsey Road, Sunbury-on-Thames, Middlesex Anal. Chem., 44, 1107 (1972) Versatile Low Cost Laboratory Integrator DONALD R. KENDALL, Atomics International, A Division of North American Rockwell Corporation, Canoga Park, Calif. 91304 Anal. Chem., 44, 1109 (1972) Inexpensive Mercury-Specific Gas Chromatographic Detector JAMES E. LONGBOTTOM, Environmental Protection Agency, National Environmental Research Center, Ana lytical Quality Control Laboratory, Cincinnati, Ohio 45268
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Anal. Chem., 44, 1111 (1972) ANALYTICAL CHEMISTRY, VOL. 44, NO. 6, MAY 1972 ·
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