Contributed Articles Thermodynamic Constants of the Adducts Formed with Heterocyclic Nitrogen Bases and Nickei(ll)Dithiophosphates. Teresa Marshall and Quintus Fernando 1346 Concentration and Separation of Trace Metal Cations by Complexation on Polyamine-Polyurea Resins. Joseph Dingman, Jr., Sidney Siggia, Carlos Barton, and Κ. Β. His· cock 1351 Determination of Atmospheric Sulfur Dioxide by Differ ential Pulse Polarography. R.W. Garber and C. E.Wilson 1357 Bipolar Digipotentiogrator for Electroanalytical Uses. Direct Conversion of Charge to Digital Number. W. W. Goldsworthy and R. G. Clem 1360 Rhodanese Enzyme Determination Using Ion-Selective Membrane Electrodes. R. A. Llenado and G. A. Rechnitz 1366 Activity Studies of Charged and Uncharged Molecules Using Detergent Gel Membrane Systems. Claudio Botre, Marco Mascini, and Adriana Memoli 1371 Evaluation of Precision of Quantitative Molecular Ab sorption Spectrometric Measurements. J. D. Ingle, Jr., and S. R. Crouch 137 Nondestructive Charged Particle Activation Analysis Using Short-Lived Nuclides. Jean-Luc Debrun, 0. C. Riddle, and E. A. Schweikert 1386 Ion-Exchange, Coordination, and Adsorption Chromato graphic Separation of Heavy-End Petroleum Distillates. D. M. Jewell, J. H. Weber, J. W. Bunger, Henry Plancher, and D. R. Latham 1391 Nuclear Magnetic Resonance of Petroleum Fractions. Carbon-13 and Proton Nuclear Magnetic Resonance Characterizations in Terms of Average Mpleculer Pa rameters. D. R. Clutter, Leonidas Petrakis, R. L. Stenger, Jr., and R. K. Jensen 1395 The K-Nearest Neighbor Classification Rule (Pattern Recognition) Applied to Nuclear Magnetic Resonance Spectral Interpretation. B. R. Kowalski and C. F. Bender 1405 On-Line Elemental Analysis of Gas-Chromatographic Effluents. S. A. Liebman, D. H. Ahlstrom, T. C. Creighton, G. D. Pruder, R. Averitt, and E. J. Levy 1411 Predicting Gas-Chromatographic Resolution for Pairs of N-Alkane Homologs. R. S. Swingle and L. B. Rogers
1415
Principal-Component Analysis Applied to Chromato graphic Data. Donald Macnaughtan, Jr., L. B. Rogers, and Grant Wernimont 1421 Effect of Dead Volume on Efficiency of a Gas Chromato graphic System. Virgil Maynard and Eli Grushka 1427
Quantitative Determination of 5-Hydroxyindole-3-Acetic Acid in Cerebrospinal Fluid by Gas ChromatographyMass Spectrometry. Leif Bertilsson, A. J. Atkinson, Jr., J. R. Althaus, Ase Harfast, Jan-Erik Lindgren and Bo Holmstedt 1434 Hexafluoroacetone Ketals as Derivatives for Positional and Geometrical Characterization of Double Bonds. B. M. Johnson and J. W. Taylor 1438 Laser-Excited Atomic Fluorescence Flame Spectrometry as an Analytical Method. L. M. Fraser and J. D. Winefordner 1444 Atomic Absorption Determination of Chloride Utilizing the Beilstein Test. D. F. Tomkins and C. W. Frank 1451 Induction Furnace Method in Atomic Spectrometry. Yair Talmi and G. H. Morrison 1455
Notes Use of Induction Furnace Source for Spectrometric Determination of Iodine. Yair Talmi and G. H. Morrison 1467 Determination of Aluminum in Biological Material by Atomic Absorption Spectrophotometry. S. S. Krishnan, K. A. Gillespie, and D. R. Crapper 1469 Uiltrasonic Nebulization in Atomic Absorption Spectro photometry. T. R. Copeland, K. W. Olson, and R. K. Skogerboe 1471 Direct Isotopic Determination by Atomic Fluorescence Spectrometry. Claude Veillon and J. Y. Park
1473
Arsenic Determination at Sub-Microgram Levels by Arsine Evolution and Flameless Atomic Absorption Spectrophotometric Technique. R. C. Chu, G. P. Barron, and P. A. W. Baumgarner 1476 Emission Spectrometric Determination of Arsenic. Lichte and R. K. Skoerboe
F. E. 1480
Determination of Metallic-Element Impurities in Ura nium Hexafluoride by Spark Source Mass Spectrometry. Ο. Η. Howard 1482 Exact Mass Measurement Accuracy from CEC 21-110Β Mass Spectrometer and Commercial Data System DS-30. R. S. Gohlke, G. P. Happ, D. P. Maier, and D. W. Stewart 1484 Determination of Mass Spectrometric Sensitivity Data for Hydroaromatic Compounds. J. L. Shultz, A. G. Sharkey, Jr., and R. A. Brown 1486 Separation and Identification of Multicomponent Mix tures Using Centri-Chromatography/Mass Spectrom etry. F. W. Karasek and P. W. Rasmussen 1488 ANALYTICAL CHEMISTRY, VOL. 44, NO. 8, JULY 1972
·
3A
Contributed Articles Tetraphenylboric Acid Salts as Stationary Phases in Gas Chromatography. G. E. Baiulescu a n d V. A. Hie Gas Chromatographic Determination of Residual M e t h anol in Food Additives. M. A. L i t c h m a n a n d R. P. U p t o n Rapid Determination of Twenty Amino Acids by Gas Chromatography. J . P. Hardy a n d S. L. Kerrin Analysis of Purine and Strychnos Alkaloids by Pressure Liquid Chromatography. Cheng-Yi Wu a n d Sidney Siggia Use of Sample Loops with Micro-Packed Columns in Gas Chromatography. D. E. D u r b i n a n d Jackie Fruge Neutron Activation Analysis of Copper by Substoichiometric Extraction with Neocuproine. R. A. N a d k a r n i a n d B. C. Haldar Comparison of Neutron Activation Analysis and Other Analyses Procedures for Fish Samples. N. D. Eckhoff, C. J . P a p p a s , a n d C. W. Deyoe Determination of Trace Quantities of U r a n i u m in Bi ological Materials by Neutron Activation Analysis Using a Rapid Radiochemical Separation. D. A. Becker a n d P. D. LaFleur Spectrophotometric Determination of Sulfite with Mer curic Thiocyanate and Ferric Ion. W. L. Hinze, J a m e s Elliott, a n d R. E. H u m p h r e y T r i m e t h y l p h e n y l a m m o n i u m Bromide as a Selective Quantitative Precipitant for Gold or T h a l l i u m . W. W. White Spectrophotometric Determination of Sulfur Dioxide by Reduction of I r o n ( l l l ) in the Presence of Ferrozine. A m i r Attari a n d Bruno Jaselskis
1490
1495
1497
1499
1502
1504
Gas Chromatographic Measurement of Adsorption Char acteristics of Isobutylene-Activated Alumina System with Nonlinear Isotherm. S h u i c h i Kagawa, K a t s u m i Fujita, K e n j i T a d a , a n d Issei N a k a m o r i
1540
Improved Method for the Preparation of Sulfur Dioxide f r o m Barium Sulfate for Isotope Ratio Studies. S. A. Bailey a n d J . W. S m i t h
1542
B a r i u m Ion-Selective Electrode Carrier Complex. R . J . Levins
1544
Based on a
Neutral
Noble Gas Adsorption Characteristics of Charcoal Beds: Van Deemter's Coefficients Evaluation. G. G. Curzio a n d A. F. Gentili
1508
1511
Aids for Analytical Chemists Inexpensive Absorption Cell for Use in the Deter mination of Mercury by the Flameless Atomic Absorption Technique. D. R. W o l b e r a n d R. E. Bosshart
1546
An Easily Constructed Alkali Flame Ionization Detector. W. H. Stewart
1547
Novel Type of Hydrogenator. F. S m i t h
1548
P. G. S i m m o n d s a n d C.
Rapid Screening of Pencil Paint for Lead by a Combus tion-Atomic Absorption Technique. Bruce M c D u f f i e
1551
New Infrared Mulling Agent.
1551
D. H. Marr
Correction. Intrinsic End-Point Errors in Titration with Ion Selective Electrodes. Chelometric Titrations. P. W. Carr 1513 © Copyright 1972 by the American Chemical Society
1515
ABC 1517
Apparent Ionization Constants of Water in Aqueous Organic Mixtures and Acid Dissociation Constants of Protonated Co-Solvents in Aqueous Solution. Ε. Μ. Woolley a n d L. G. Hepler
1520
MANUSCRIPT REQUIREMENTS published in December 1971 issue, page 2039, outlines scope and copy requirements to be observed in preparing manuscripts for consideration. Manuscript (4 copies) should be sub mitted to ANALYTICAL CHEMISTRY, 1155 Sixteenth St., N.W., Washing ton, D. C. 20036. The American Chemical Society assumes no responsibility for the statements and opinions advanced by contributors to its publications. Views expressed in the editorials are those of the editors and do not necessarily represent the official position of the American Chemical Society. 1972 Subscription Rates lyr.
2 yr.
$ 5.00 7.00 15.00
$ 9.00 12.00 27.50
3 yr.
Determination of Composition of Mixtures of Diastereoisomeric Forms of Weak Acids by pH Titration. Neil P u r d i e , M. B. T o m s o n , a n d G. K. Cook
1525
Determination of Carbon Monoxide in Blood. bert, R. R. T s c h o r n , a n d P. A. H a m l i n
Postage: Canada and Pan-American Union, $4.00; foreign, $5.00. Sin gle copies: current, $2.00 except Annual Reviews, $3.00 each. Rates for back issues and volumes are available from Special Issues Sales Dept, 1155 Sixteenth St.. N.W., Washington, D. C. Claims for missing numbers will not be allowed if received more than 60 days from date of mailing plus time normally required for postal delivery of journal and claim. No claims allowed because of failure to notify the Subscription Service De partment of a change of address or because copy is "missing from files."
1529
J . L. Lam
Differential Scanning Calorimetry as a General Method for Determining Purity and Heat of Fusion of HighPurity Organic Chemicals. Application to 64 Com pounds. Candace Plato
1531
P e r m e a m e t r y in the Knudsen-Flow Regime. a n d Clyde Orr, Jr.
1534
J . F. Brock
4 A
·
1537
A N A L Y T I C A L CHEMISTRY, VOL. 4 4 , NO. 8, JULY 1 9 7 2
bob
1523
Members, domestic and foreign Nonmembers, domestic and Canada Nonmembers, foreign except Canada
Low Level Calibration Mixtures for Gaseous Pollutants. R. C. Paule
1544
1506
Ultrasonic Velocity in W a t e r - D e u t e r i u m Oxide Mixtures. A Basis for Deuterium Determination in Water Solutions. J . G. M a t h i e s o n a n d Β. Ε. Conway
Photometric Determination of Picomole Quantities of Calcium. D. C. Marcus a n d R. L. J a m i s o n
Correspondence
Those interested in joining the American Chemical Society should write to Admissions Department at the Washington Office. Published monthly with Review issue added in April and a Laboratory Guide in August by the American Chemical Society, from 20th and North ampton Sts., Easton, Pa. 18042; Executive Offices, Editorial Head quarters, and Subscription Service Department, 1155 Sixteenth St., N.W., Washington, D. C. 20036; Advertising Office, 142 East Ave., Norwalk, Conn. 06851. ANALYTICAL CHEMISTRY and other ACS periodicals are available on microfilm. For information write to: MICROFILM, Special Issues Sales, American Chemical Society, 1155 Sixteenth St.. N.W., Washington, D. C. 20036. Second class postage paid at Washington, D. C. and at additional mailing offices. CHANGE OF ADDRESS: Notify Subscription Service Department, American Chemical Society. 1155 Sixteenth St., N.W., Washington, D. C. 20036. Such notification should include both old and new addresses, with ZIP code numbers, and be accompanied by mailing label from a recent issue. Allow four weeks for change to become effective.
1479
