Articles

BRIEFS

Articles Monitoring of Formation Rates of Thin Films in Laser-induced Chemical Vapor Deposition 2402 Comparison between acoustic wave, photoacoustic response, transmittance, reflectance, and quartz crystal microbalance m e a s u r e m e n t s is performed for in situ laser-induced chemical vapor thin-film deposition. Ho-ming Pang and Edward S. Yeung*, Ames LaboratoryUSDOE and Department of Chemistry, Iowa State University, Ames, IA 50011 Fundamentals of Sinusoidal Flow Sequential Injection Spectrophotometry 2407 The design of the sequential injection analyzer is based on the mutual penetration of sample and reagent zones, which are sequentially stacked into a tubular conduit, injected into a reactor, and transported to the detector. Thomas Gubeli, Alitea U.S.A., P.O. Box 26, Medina, WA 98039 and Gary D. Christian and Jaromir Ruzicka*, Department of Chemistry, BG-10, University of Washington, Seattle, WA 98195 Determination of the Diffusion Coefficients of Iodine in Porphyrin Thin Films by Utilization of the Battery Effect in Schottky Barrier Devices 2414 By analyzing the time evolution of the device's dark current, the diffusion coefficient of iodine in a series of tetraphenylporphyrins is determined to be approximately 10 ~ 1 5 cm 2 /s (increasing in order of central substituent Mg < Cu < Zn < H 2 < Ni). W. Andrew Nevin, Department of Electrical and Electronic Engineering, Trent Polytechnic, Burton Street, Nottingham NG1 4BU, England Multichannel Amperometric Detection System for Liquid Chromatography and Flow Injection Analysis 2418 A 16-working electrode electrochemical detector in a parallel configuration and a computer-controlled multichannel potentiostat are developed. When used for the detection of catecholamines separated by LC, the response is linear over the range 1 0 ~ 5 - 1 0 - 9 , and a detection limit of - 0 . 1 pg epinephrine injected is achieved. Johan C. Hoogvliet*, Johannes M. Reijn, and Wouter P. van Bennekom, Faculty of Pharmacy, Utrecht University, P.O. Box 80.082, 3508 TB Utrecht, The Netherlands

Development of the H-Point Standard-Additions Method for Ultraviolet-Visible Spectroscopic Kinetic Analysis of Two-Component Systems 2424 The H-point standard addition method is extended to kinetic analysis; time is included as an additional measurement dimension. Good results are obtained for analyte concentration in the presence of a complex matrix and for binary mixtures. Francisco Bosch-Reig, Pilar Campins-Falco*, Adela Sevillano-Cabeza, Rosa Herrâez-Hernandez, and Carmen Molins-Legua, Departamento de Quimica Analitica, Facultad de Quimica, Universidad de Valencia, Burjasot (Valencia), Spain Simultaneous Determination of Elemental Ratios in Coal by Direct Powder Injection into a Helium Microwave Induced Plasma 2430 C, H, CI, and S are determined by direct solid sampling. C/H ratios are determined to within - 10% accuracy when simultaneous measurements are performed and standards are similar in composition. Jay M. Gehlhausen and Jon W. Carnahan*, Department of Chemistry, Northern Illinois University, DeKalb, IL 60115 Automated Model Selection for the Simulation of Carbon-13 Nuclear Magnetic Resonance Spectra of Cyclopentanones and Cycloheptanones 2435 • A method to select appropriate regression models for the prediction of 13 C NMR chemical shifts is developed. Models are selected from a database containing previously reported equations and newly generated ones developed for cyclopentanones and cycloheptanones. The models yield a mean standard error of 1.12 ppm. Jon W. Ball, Lawrence S. Anker, and Peter C. Jurs*, Department of Chemistry, The Pennsylvania State University, 152 Davey Laboratory, University Park, PA 16802 Scanning Electrochemical Microscopy. 11. Improvement of Image Resolution by Digital Processing Techniques 2442 A linear combination of Laplacian and Gaussian filters applied to scanning electrochemical microscope images provides processed images with improved resolution (comparable to the resolution obtained with tips three to four times smaller). Chongmok Lee, David O. Wipf, and Allen J. Bard*, Department of Chemistry and Biochemistry, The University of Texas at Austin, Austin, TX 78712 and Keith Bartels and Alan C. Bovik, Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, TX 78712

*Corresponding author • Supplementary material available 1014 A · ANALYTICAL CHEMISTRY, VOL. 63, NO. 21, NOVEMBER 1, 1991

BRIEFS Quantitative Surface Analysis of Organic Polymer Blends Using a Time-of-Flight Static Secondary Ion Mass Spectrometer 2447 Surface compositions of bisphenol-A polycarbonate/ polystyrene and tetramethylcarbonate/polystyrene polymer blends are determined using TOF-SSIMS and XPS. Accuracy for both TOF-SSIMS and XPS is within ±0.1 monomer fraction, whereas the typical precision of the TOF-SSIMS results is primarily determined by counting statistics and is generally better than that of the XPS re suits. Patrick M. Thompson, Surface Science Section, Research Laboratories, Eastman Kodak Company, Rochester, NY 14650-2132 Determination of the Concentration and Stable Isotopic Composition of Nonexchangeable Hydrogen in Organic Matter 2456 Multiple isotopic equilibrations of exchangeable hydrogen with isotopically different water vapors, subsequent bulk 5D determinations, and mass balance calculations reveal the concentration and D/H ratio of nonexchangeable hydrogen. Arndt Schimmelmann, University of California at San Diego, Scripps Institution of Oceanography, La Jolla, CA 92093-0215 Theoretical Analysis of Probe Dynamics in Flow Injection/ Membrane Introduction Mass Spectrometry 2460 A mathematical analysis is performed on membrane pervaporation used in conjunction with FIA. The effects of flow rate, injection time profile, mixing in the flow chamber, partitioning onto the membrane surface, diffusion through the membrane, and membrane thickness and temperature on the analyte flux are discussed and compared with experimental results. Gow-Jen Tsai, Glen D. Austin, Mei J. Syu, and George T. Tsao, Laboratory of Renewable Resources Engineering, Purdue University, West Lafayette, IN 47907 and Mark J. Hayward, Tapio Kotiaho, and R. Graham Cooks'", Department of Chemistry, Purdue University, West Lafayette, IN 47907 Supercritical Fluid Chromatography and Time-of-Flight Secondary Ion Mass Spectrometry of Poly(dimethylsiloxane) Oligomers in the Mass Range 1000-10 000 Da 2466 SFC and TOF-SIMS give similar results when determining the average molecular weights and the shape of oligomer distributions in the mass range up to 3000 Da. Differences occur at higher masses because of mass discrimination effects. Birgit Hagenhoff, Alfred Benninghoven*, Herbert Barthel, and Wolfgang Zoller, Physikalisches Institut der Universitàt Munster, Wilhelm-Klemm-Strasse 10, D-4400 Munster, F.R.G.

Matrix-Assisted UV-Laser Desorption/lonization Mass Spectrometric Analysis of Monoclonal Antibodies for the Determination of Carbohydrate, Conjugated Chelator, and Conjugated Drug Content 2470 Methods are described for estimating carbohydrate content and determining quantity and distribution of chelators and drugs bound to monoclonal antibodies using m a trix-assisted UV-laser desorption/ionization MS. Results are compared with currently used methods. Marshall M. Siegel*, Irwin J. Hollander, Philip R. Hamann, John P. James, and Lois Hinman, American Cyanamid Company, Medical Research Division, Lederle Laboratories, Pearl River, NY 10965, Bryan J. Smith, Andrew P. H. Farnsworth, Alison Phipps, and David J. King, Celltech, Ltd., Slough SL1 4EN Berkshire, U.K., and Michael Karas, Arndt Ingendoh, and Franz Hillenkamp, Institute of Medical Physics, University of Munster, D-4400 Munster, F.R.G. Direct Introduction of Large-Volume Urine Samples into an 0n-Line Immunoaffinity Sample Pretreatment-Capillary Gas Chromatography System 2481 An immunoaffinity precolumn containing immobilized antibodies raised against the synthetic steroid hormone β-19-nortestosterone is used for the automated sample pretreatment of 5 - 2 5 - m L urine samples containing β-19nortestosterone, norethindrone, and norgestrel. The 19norsteroids can be determined at the ppt level. A. Farjam, J. J. Vreuls, W.J.G.M. Cuppen, U.A.Th. Brink­ man*, and G. J. de Jong, Department of Analytical Chemistry, Free University, De Boelelaan 1083, 1081 HV Amsterdam, The Netherlands Tandem Mass Spectrometry of Very Large Molecules: Serum Albumin Sequence Information from Multiply Charged Ions Formed by Electrospray Ionization 2488 Limited primary sequence information is obtained for in­ tact 66 kD serum albumin proteins from 10 different spe­ cies by electrospray ionization tandem MS. Joseph A. Loo, Charles G. Edmonds, and Richard D. Smith*, Chemical Sciences Department, Pacific Northwest Lab­ oratory, Richland, WA 99352 Nondependence of Diffusion-Controlled Peak Dispersion on Diffusion Coefficient and Ionic Mobility in Capillary Zone Electrophoresis without Electroosmotic Flow 2499 The single analyte-specific property responsible for peak broadening is the charge number, not the diffusion coef­ ficient, D, or the ionic mobility, u. This result is derived theoretically by substituting the ratio u/D, occurring in the conventional expression for the plate number, with the relation between these parameters as given by Ein­ stein. Ernst Kenndler* and Christine Schwer, Institute for Ana­ lytical Chemistry, University of Vienna, Wâhringerstrasse 38, A 1090 Vienna, Austria

1016 A · ANALYTICAL CHEMISTRY, VOL. 63, NO. 21, NOVEMBER 1, 1991

BRIEFS Migration Behavior of Cationic Solutes in Micellar Electrokinetic Capillary Chromatography

2503

M i g r a t i o n of cationic s o l u t e s i n M E C C is q u a n t i t a t i v e l y d e s c r i b e d t h r o u g h m a t h e m a t i c a l m o d e l s t h a t allow t h e p r e d i c t i o n of s o l u t e b e h a v i o r b a s e d o n a l i m i t e d n u m b e r of e x p e r i m e n t s a n d f a c i l i t a t e t h e o p t i m i z a t i o n of s e p a r a tions. J o o s t K. Strasters and Morteza G. Khaledi*, Department of Chemistry, North Carolina State University, P.O. Box 8204, Raleigh, NC 27695

High-Speed Countercurrent Chromatography Used for Alkylbenzene Liquid-Liquid Partition Coefficient Determination 2508 P a r t i t i o n coefficients of a l k y l b e n z e n e s from b e n z e n e t o dodecylbenzene are m e a s u r e d by CCC in seven m e t h a n o l r i c h c o m p o s i t i o n s ( w a t e r < 2 0 % v/v) of t h e h e p t a n e - m e t h a n o l - w a t e r biphasic liquid system. A l a i n B e r t h o d * a n d M a d e l e i n e B u l l y , Laboratoire des Sciences Analytiques, UA CNRS 435, Université de Lyon 1, 69622 Villeurbanne Cedex, France

Real-Time Principal Component Analysis Using Parallel Kalman Filter Networks for Peak Purity Analysis 2512 A r e c u r s i v e a l g o r i t h m for p e r f o r m i n g p r i n c i p a l c o m p o n e n t a n a l y s i s on m u l t i v a r i a t e d a t a s e t s is d e s c r i b e d . T h e p r o c e d u r e , b a s e d on p r i n c i p l e s of t h e a d a p t i v e K a l m a n filter, is u s e d t o d e t e r m i n e t h e r a n k of m u l t i w a v e l e n g t h chromatographic data. S t e p h e n J. Vanslyke and P e t e r D. Wentzell*, Trace Analysis Research Centre, Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4J3

Concentration of Hydrophobic Organic Compounds and Extraction of Protein Using Alkylammoniosulfate Zwitterionic Surfactant Mediated Phase Separations (Cloud Point Extractions) 2520 T h e s y n t h e s i s a n d e v a l u a t i o n of t h e p h a s e s e p a r a t i o n b e h a v i o r of t w o z w i t t e r i o n i c s u r f a c t a n t s , 3-[nonyl- (or d e cyl-) d i m e t h y l a m m o n i o ] p r o p y l s u l f a t e , is r e p o r t e d . R e s u l t s i n d i c a t e t h a t s u c h s u r f a c t a n t s c a n be u s e d for t h e e x t r a c t i o n / p r e c o n c e n t r a t i o n of h y d r o p h o b i c s p e c i e s i n a m a n n e r s i m i l a r to t h a t r e p o r t e d for nonionic s u r f a c t a n t s . Tohru Saitoh and Willie L. Hinze*, Department of Chemistry, Laboratory for Analytical Micellar Chemistry, Wake Forest University, P.O. Box 7486, Winston-Salem, NC 27109

Separation and Determination of Copper, Zinc, Palladium, Iron, and Manganese with meso-Tetrakis(3-bromo4-sulfophenyl)porphine and Reversed-Phase Ion-Pair Liquid Chromatography 2529 X u e - J u n Xu, H u a - S h a n Zhang, Chuan-You Zhang, and J i e - K e (Jai-Kai) Cheng*, Department of Chemistry, Wuhan University, Wuhan 430072, China

Technical Notes Determination of Total and Free Sulfur Dioxide in Wine by Flow Injection Analysis and Gas-Diffusion Using p-Aminoazobenzene as the Colorimetric Reagent 2532 Jordi Bartroli*, Manel Escalada, Cecilia J i m e n e z J o r quera, a n d J u l i a n Alonso, Department de Quimica, Universitat Autônoma de Barcelona, 08193 Bellaterra, Spain

Bulk-Electrolysis Flow-Cell System for UV-Visible and X-ray Absorption Spectroelectrochemical Analysis 2535 David H. Igo, R. C. Elder*, and William R. Heineman*, Department of Chemistry, University of Cincinnati, Cincinnati, OH 45221-0172 and H o w a r d D. D e w a l d , D e p a r t m e n t of Chemistry and Condensed Matter and Surface Science Program, Ohio University, Athens, OH 45701-2979

0n-Line Preconcentration and Volatilization of Iodine for Inductively Coupled Plasma Atomic Emission Spectrometry 2539 Scott P. Dolan, Scott A. Sinex, and S t e p h e n G. Capar, Division of Contaminants Chemistry, Food and Drug Administration, Washington, DC 20204 and Akbar Montaser* and Robert H. Clifford, Department of Chemistry, George Washington University, Washington, DC 20052

Determination of Small Amounts of Water in Dimethylformamide and Dimethylsulfoxide Using Luminescence Lifetime Measurements of Europium (III) 2542 Stefan Lis and Gregory R. Choppin*, Department of Chemistry, The Florida State University, Tallahassee, FL 32306-3006

Correction. Horizontal Touch Voltammetric AnalysisDetermination of Insoluble Electroactive Species in Films at the Air/Water Interface 2544 Cary J. Miller and Allen J. Bard*, Department of Chemistry, The University of Texas at Austin, Austin, TX 78712

Correspondence Quadrupole Fourier Transform Mass Spectrometry of Oligosaccharides 2526 J a m e s A. Carroll, Lambert Ngoka, Sési McCullough, Eric Gard, A. Daniel J o n e s , a n d Carlito B. Lebrilla*, Department of Chemistry and Facility for Advanced Instrumentation, University of California, Davis, CA 95616

1018 A · ANALYTICAL CHEMISTRY, VOL. 63, NO. 21, NOVEMBER 1, 1991