Briefs
Applications of the Piezoelectric Crystal Detector in Analytical Chemistry 1890 Various applications, including use for detection in ambient air, as a sorption detector in GC and LC, in polymer research, and for the determination of water are reviewed. J. Hlavay and G. G. Gullbault,* Department of Chemistry, University of New Orleans, New Orleans, La. 70122 Anal. Chem., 49 (1977) Square Wave Voltammetry at the Dropping Mercury Electrode: Theory 1899 T h e theoretical response for t h e application of square wave voltammetry at a dropping mercury electrode is presented, with particular reference to points of current measurement. J. H. Christie, John A. Turner, and R. A. Osteryoung,* Department of Chemistry, Colorado State University, Fort Collins, Colo. 80523 Anal. Chem., 49 (1977) Square Wave Voltammetry at the Dropping Mercury Electrode: Experimental 1904 T h e technique is shown to have t h e same order of sensitivity as differential pulse polarography b u t is much faster to perform. John A. Turner, J . H. Christie, M. Vukovic, and R. A. Osteryoung,* Department of Chemistry, Colorado State University, Fort Collins, Colo. 80523 Anal. Chem., 49 (1977) Automated Electrodic Potentiometry System
1908
A microcomputer-controlled system for controlling solution redox potentials by electric currents is described. Richard W. Hendler, Section on Membrane Enzymology, Laboratory of Cell Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Md. 20014, David Songco, Computer Systems Laboratory, Division of Computer Research and Technology, National Institutes of Health, Bethesda, Md. 20014, and Tom Clem, Biomedical Engineering and Instrumentation Branch, Division of Research Services, National Institures of Health, Bethesda, Md. 20014 Anal. Chem. 49 (1977) Automated Electrodic Potentiometry of Potassium Ferricyanide and Respiratory Components 1914
Electrocatalysis of the Reduction of Iron(lli) by Halides Adsorbed at Platinum Electrodes in Perchloric Acid Solutions 1918 T h e electrocatalysis of t h e Fe(III) reduction a t P t electrodes is studied for C I - , Br~, and I - present at trace levels in dilute HC10 4 . Dennis C. Johnson* and Edward W. Resnick, Department of Chemistry, Iowa State University, Ames, Iowa 50011 Anal. Chem., 49 (1977) Redox Potential and Quinone Content of Cigarette Smoke 1924 Methods are described for measuring the redox potential of smoke aerosol, and for determining quinones present in smoke, tobacco, and pyrolyzates. T h e redox potential and quinone content are shown to be related. Irwin Schmeltz,* Jeff Tosk, Genie Jacobs, and Dietrich Hoffmann, Naylor Dana Institute for Disease Prevention, American Health Foundation, Valhalla, N.Y. 10595 Anal. Chem., 49 (1977) Analytical Aspects of Immobilized Enzyme Columns 1929 T h e dependence of peak height, area, and half width on t h e system parameters is determined and related to models of chemical reactors. A thermochemical urea analyzer is used to assess t h e model. Richard S. Schifreen, D. Alan Hanna, Larry D. Bowers, and Peter W. Carr,* Department of Chemistry, University of Georgia, Athens, Ga. 30602 Anal. Chem., 49 (1977) Relating Molecular Structure to Metal Chelate Stability and Reagent Selectivity: Abstract Factor Analysis of the Chelate Formation Equilibria for Some Diaminetetracarboxylic Acids 1940 T h e formation constants of t h e EDTA family are predicted by a simple model. Four independent factors are found sufficient to reproduce t h e d a t a to within experimental uncertainty. David L. Duewer and Henry Freiser,* Department of Chemistry, The University of Arizona, Tucson, Ariz. 85721 Anal. Chem., 49 (1977)
A new system for electrodic potentiometry is demonstrated with t h e potentiometric titrations of ferricyanide, cytochrome c, and E. coli membranes. Richard W. Hendler, Section on Membrane Enzymology, Laboratory of Cell Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Md. 20014 Anal. Chem., 49 (1977)
* Corresponding author
1084 A · ANALYTICAL CHEMISTRY, VOL. 49, NO. 13, NOVEMBER 1977
Briefs
Characterization of the Calcium Form of Chelex-100 for Trace Metal Studies 1950
Determination of Phenylethylmalonamide by ElectronCapture Gas Chromatography 1969
Effects of p H on column u p t a k e of trace metals from river water media are examined, resin site homogeneity toward trace Cd or P b is established, and separation factors for Cd, Cu, P b , a n d Zn vs. Ca-Chelex are measured. Paul Figura and Bruce McDuffie,* Laboratory for Trace Methods and Environmental Analysis, State University of New York at Binghamton, Binghamton, N.Y. 13901 Anal. Chem., 49 (1977)
T h e procedure involves a one-step extraction a n d derivatization with trifluoroacetic anhydride(TFAA) for analysis by electron-capture gas-liquid chromatography. Jack E. Wallace,* Horace E. Hamilton, Eugene L. Shimek, Jr., and Harvey A. Schwertner, Department of Pathology, The University of Texas Health Science Center at San Antonio, San Antonio, Tex. 78284 and Klaus D. Haegele, Department of Pharmacology, The University of Texas Health Science Center at San Antonio, San Antonio, Tex. 78284 Anal. Chem., 49 (1977)
Liquid Chromatography of Chlorinated Biphenyls on Pyrolytically-Deposited Carbon 1954 Porous silica coated with pyrolytically-deposited carbon is a selective stationary phase for t h e liquid chromatography of polychlorinated biphenyls. Toshihiko Hanai and Harold F. Walton,* Department of Chemistry, University of Colorado, Boulder, Colo. 80309 Anal. Chem., 49 (1977) Dynamic Slurry-Packing Technique for Liquid Chromatography Columns
1958
A new packing apparatus, based on a combination of stirring action a n d high pressure, for simultaneous packing of u p t o six columns is described. H. P. Keller, F. Erni, H. R. Linder, and R. W. Frei,* Analytical Research and Development, Pharmaceutical Division, Sandoz, Ltd., 4002-Basle, Switzerland Anal. Chem., 49 (1977) Determination of 4,4'-Alkyl- and Alkoxy-Disubstituted Azoxybenzenes by Isocratic Reverse Phase High Performance Liquid Chromatography 1963 T h e precision is less than 0.5% R S D and t h e detection limits are between 0.2 a n d 1.6 ng with a methanol mobile phase containing 10% (w/v) of water. Satoru Shiono,* Titose Miyakura, Junzo Enomoto, and Takashi Imamura, Central Research Laboratory, Mitsubishi Electric Corporation, Amagasaki, Hyogo, Japan Anal. Chem., 49 (1977) Quantitative Determination of Benzoylecgonine and Cocaine in Human Biofluids by Gas-Liquid Chromatography 1965 Cocaine a n d its metabolite benzoylecgonine are determined in both h u m a n plasma a n d urine by quantitative gas-liquid chromatographic methods with nitrogen, electron capture, a n d flame ionization detection. M. J. Kogan,* K. G. Verebey, A. C. DePace, R. B. Resnick, and S. J. Mule, New York State Office of Drug Abuse Services, Testing and Research Laboratory, Brooklyn, N.Y. 11217, and New York Medical College, Department of Psychiatry, New York, N.Y. 10029 Anal. Chem., 49 (1977)
Simultaneous Determination of Cocaine and Benzoylecgonine in Urine by Gas-Liquid Chromatography 1974 T h e analytical procedure has detection limits of
