Briefs Experimental Studies on a New Polar Bonded Liquid Chromatography Phase A new polar b o n d e d s t a t i o n a r y p h a s e for L C is p r e p a r e d from l - t r i m e t h o x y s i l y l - 2 - c h l o r o m e t h y l p h e n y l e t h a n e a n d Corasil II. E v i d e n c e is p r e s e n t e d w i t h r e g a r d t o t h e p a r t i t i o n i n g m e c h a n i s m involved w h e n using t h e s u p p o r t w i t h a n o n p o l a r solvent. Eli G r u s h k a a n d E d w a r d J . Kikta, J r . , Department of Chemis try, State University of New York at Buffalo, Buffalo, N.Y. 14214 Anal. Chem., 46, 1370 (1974)
Method for Prediction of Partition Coefficients in Liquid-Liquid Chromatography C h a n g e in selectivity d u e t o c h a n g e s of c o m p o s i t i o n of elu e n t s in a l i q u i d - l i q u i d c h r o m a t o g r a p h i c s y s t e m is s t u d i e d a n d t h e p r a c t i c a l i m p l i c a t i o n s are discussed. P a u l M e n h e e r e , Claude Devillez, Claude Eon, and Georges Guiochon, Laboratoire de Chimie Analytique Physique, Ecole Po lytechnique, 17, rue Descartes, 75005—Paris Anal. Chem., 46, 1375 (1974)
Structure-Retention Relationships in the Gas Chromatography of Nucleosides S t r u c t u r e - r e t e n t i o n t i m e c o r r e l a t i o n s for 32 nucleoside t r i m e t h y l s i l y l d e r i v a t i v e s a r e s t u d i e d using OV-17 a n d S E - 3 0 liquid p h a s e s . M e t h y l e n e u n i t values a r e m e a s u r e d w i t h a precision of ± 0 . 0 2 u n i t . S. E. H a t t o x a n d J a m e s A. McCloskey, Institute for Lipid Re search and Marrs McLean Department of Biochemistry, Baylor College of Medicine, Houston, Texas 77025 Anal. Chem., 46, 1378 (1974)
Role of the Solvent in Liquid-Solid Chromatography—A Review T h r e e m o d e l s of a d s o r p t i o n in l i q u i d - s o l i d c h r o m a t o g r a p h y ( S n y d e r , Soczewinski, S c o t t - K u c e r a ) a r e critically ex a m i n e d w i t h r e s p e c t t o t h e role of t h e s o l v e n t in affecting s e p a r a t i o n in isocratic a n d g r a d i e n t elution s y s t e m s . L. R. Snyder, Technicon Instruments Corp., Tarrytown, N.Y. 10591 Anal. Chem., 46, 1384 (1974)
Theoretical Comparison of Chromatography and Spectrometry as Methods of Measuring Weak Complexation Constants Complexation constants measured by chromatography are likely t o b e less m e a n i n g f u l t h a n t h o s e m e a s u r e d by spec troscopy unless suitable corrections are made. Complexa tion c o n s t a n t s d e p e n d on t h e n a t u r e of t h e i n e r t s o l v e n t used. C l a u d e Eon a n d Georges Guiochon, Laboratoire de Chimie Ana lytique Physique, Ecole Polytechnique, 17, rue Descartes, Paris 5 e , France Anal. Chem., 46, 1393 (1974)
Theory of Affinity Chromatography Separations S t e r i c blocking of ligand sites is i m p o r t a n t a t high loadings, while only t h e initial ligand l o a d i n g a n d t h e dissociation c o n s t a n t a r e i m p o r t a n t a t low loadings. Phillip C. W a n k a t , School of Chemical Engineering, Purdue Uni versity, West Lafayette, Ind. 47907 Anal. Chem., 46, 1400 (1974)
Accurate Determination of Ten Major and Minor Elements in Silicate Rocks Based on Separation by Cation Exchange Chromatography on a Single Column R e l e v a n t d i s t r i b u t i o n coefficients, e l u t i o n curves, r e s u l t s for two s y n t h e t i c m i x t u r e s a n d six s t a n d a r d rock s a m p l e s , a n d a m e t h o d for t h e s e p a r a t i o n of t r a c e a m o u n t s of v a n a d i u m in r o c k s from a c c o m p a n y i n g i m p u r i t i e s are p r e s e n t ed. F. W. E. Strelow, C. J . Liebenberg, and A. H. Victor, National Chemical Research Laboratory, Pretoria, Republic of South Africa Anal. Chem., 46, 1409 (1974)
Application of a Demountable Hollow Cathode Lamp as a Source for the Direct Determination of Sulfur, Iodine, Arsenic, Selenium, and Mercury by Atomic Absorption Flame Spectrometry F a v o r a b l e A A S sensitivities a n d d e t e c t i o n limits a r e o b t a i n e d , c o m p a r e d w i t h c o r r e s p o n d i n g m i c r o w a v e excited electrodeless discharge l a m p sources. G. F. K i r k b r i g h t and P. J . Wilson, Chemistry Department, Im perial College, London, S.W. 7. U.K. Anal. Chem., 46, 1414 (1974)
Vitreous Carbon Furnace with Continuous S a m p l e I n t r o d u c t i o n for A t o m i c F l u o r e s c e n c e Spectrometry A n e w efficient nebulizer is u s e d t o i n t r o d u c e c o n t i n u o u s l y samples into a vitreous carbon tube furnace to produce a t o m s which a r e excited via electrodeless d i s c h a r g e l a m p s . C. J . M o l n a r and J . D. Winefordner, Department of Chemistry, University of Florida, Gainesville, Fla. 32611 Anal. Chem., 46, 1419 (1974)
Some Applications of Spectral Overlap in Atomic Absorption Spectrometry T h e a n a l y t i c a l use of s p e c t r a l overlaps in a t o m i c a b s o r p t i o n s p e c t r o m e t r y is i n v e s t i g a t e d , i n c l u d i n g t h e i r a p p l i c a t i o n t o t h e d e t e r m i n a t i o n of major c o n s t i t u e n t s of t e c h n i c a l m a t e rials. J . D. N o r r i s and T. S. West, Chemistry Department, Imperial College of Science and Technology, London SW7 2AY, England Anal. Chem., 46, 1423 (1974)
Purification of Radioactive Tracers for Use in High Sensitivity Alpha Spectrometry P r o c e d u r e s a r e given for purification of r a d i o n u c l i d e s of t h o r i u m t h r o u g h californium, giving sufficient d e c o n t a m i n a t i o n from o t h e r a l p h a - e m i t t i n g n u c l i d e s t h a t several t r a c e r s can be u s e d s i m u l t a n e o u s l y in h i g h sensitivity a l p h a spectrometry. Claude W. Sill, Health Services Laboratory, U.S. Atomic Energy Commission, Idaho Falls, Idaho 83401 Anal. Chem., 46, 1426 (1974)
Automated Atomic Absorption Determination of Arsenic, Antimony, and Selenium in Natural Waters N a t u r a l w a t e r s a m p l e s a r e analyzed a t a r a t e of 40 s a m p l e s p e r h o u r w i t h d e t e c t i o n limits of 0.1 μg/\. for As a n d Se a n d 0.5 μg/]. for S b . S i m u l t a n e o u s d e t e r m i n a t i o n s of As a n d Se c a n be m a d e . P . D. Goulden and P e t e r Brooksbank, Canada Centre for Inland Waters, P.O. Box 5050, Burlington, Ontario, Canada Anal. Chem., 46, 1431 (1974)
A N A L Y T I C A L CHEMISTRY, VOL. 46, NO. 11, SEPTEMBER 1974 •· 857 A
Briefs Hot Atomic Absorption Spectrometry Method for the Determination of Mercury at the Nanogram and Subnanogram Level
New Type of Programmable Current-Regulated Power Supply for Operation of Hollow Cathode Lamps in a High Intensity Programmed Mode
T h e use of a g r a p h i t e f u r n a c e for m e r c u r y d e t e r m i n a t i o n is d e s c r i b e d . S e n s i t i v i t y a n d precision of 0.2 ng a n d 1.3%, r e spectively, a r e o b t a i n e d . P a r a m e t e r s w h i c h affect t h e a n a lytical s e n s i t i v i t y a r e e v a l u a t e d . Haleem J . Issaq and W. L. Zielinski, J r . , NCI Frederick Cancer Research Center, Frederick, Md. 21701 Anal. Chem., 46, 1436 (1974)
A s u p p l y using i n c r e m e n t a l digital f e e d b a c k is d e s c r i b e d . T h e c o n c e p t is generally a p p l i c a b l e t o a n a l y t i c a l i n s t r u m e n t a t i o n w i t h servo feedback c o n t r o l a n d gives 0.005% relative s t a n d a r d deviation current regulation. J a m e s D. Defreese, T e r r y A. Woodruff, and H o w a r d V. Malmstadt, Department of Chemistry, University of Illinois, Urbana, 111. 61801 Anal. Chem., 46, 1471 (1974)
Fundamental Aspects of Flameless Atomic Absorption Using the Mini-Massmann Carbon Rod Atomizer
UNIPLEX: Single-Factor Optimization of Response in the Presence of Error
S o m e f u n d a m e n t a l a s p e c t s , viz. t i m e c o n s t a n t of t h e a m p l i f i e r - r e c o r d e r s y s t e m , t e m p e r a t u r e r e g i m e , dissociation of m e t a l oxides, r a t e of v a p o r i z a t i o n a n d k i n d of s h e a t i n g gas, are examined. F. J . M. J . Maessen a n d F. D. Posma, Laboratory for Analytical Chemistry, University of Amsterdam, Nieuwe Achtergracht 166, Amsterdam, The Netherlands Anal. Chem., 46, 1439 (1974)
Determination of Trace and Ultra-Trace Quantities of Rare-Earth Elements by Ion Exchange Chromatography-Mass Spectrography
D i r e c t D e t e r m i n a t i o n of Gold, C o b a l t , a n d Lithium in Blood Plasma U s i n g the MiniMassmann Carbon Rod Atomizer S o m e variables influencing t h e a n a l y t i c a l r e s u l t — n a m e l y , s a m p l e i n t r o d u c t i o n a n d altering of t h e p r o p e r t i e s of t h e g r a p h i t e — a r e e x a m i n e d . R e g r e s s i o n a n a l y s i s is a p p l i e d t o t h e c a l i b r a t i o n curves. F. J . M. J . Maessen, F. D. Posma, and J o h a n n e s Balke, Laboratory of Analytical Chemistry, University of Amsterdam, The Netherlands " Anal. Chem., 46, 1445 (1974)
Formal Photometric Titrations of Weak Bases in Ion Exchanger-Aqueous Solution Medium A p h o t o m e t r i c t i t r a t i o n function for t h e t i t r a t i o n of b a s e s w i t h HC1 in t h e p r e s e n c e of cation resin is d e s c r i b e d a n d e v a l u a t e d . V e r y weak b a s e s such as d o p a , t r y p t o p h a n , a n d s u l f a n i l a m i d e can b e d e t e r m i n e d . F r e d e r i c k F. Cantwell and Donald J . Pietrzyk, Department of Chemistry, The Universitv of Iowa, Iowa City, Iowa 52242 Anal. Chem., 46, 1450 (1974)
Chemistry of Bilirubin and Biliverdin in Dimethylformamide
T h e s t r a t e g y p r e s e n t e d n e v e r excludes a n y region of t h e factor d o m a i n from f u r t h e r investigation, offers a r a p i d a p p r o a c h t o t h e o p t i m u m , a n d converges in t h e p r e s e n c e of error. P a u l G. King a n d S t a n l e y N. Deming, Department of Chemistry, Emory University, Atlanta, Ga. 30322 Anal. Chem., 46, 1476 (1974)
N,N-
Electrochemical and spectrophotometric m e t h o d s are studied. C o n d i t i o n s a r e e s t a b l i s h e d for c o m p l e x f o r m a t i o n w i t h zinc ion. J o h n D. Van N o r m a n a n d R o b e r t Szentirmay, Department of Chemistry, Youngstown State University, Youngstown, Ohio 44503 Anal. Chem., 46, 1456 (1974)
Evaluation of a Method for Real-Time Deconvolution A m e t h o d p e r m i t t i n g on-line d e c o n v o l u t i o n of s p e c t r a a n d o t h e r t w o - d i m e n s i o n a l p r e s e n t a t i o n s is d e s c r i b e d , evalua t e d , a n d t e s t e d in p r a c t i c e . A r e n d den H a r d e r and Leo de Galan, Laboratorium voor Instrumentele Analyse, Technische Hogeschool, Delft, Nederland Anal. Chem., 46, 1464 (1974)
A m e t h o d b a s e d on cation e x c h a n g e c h r o m a t o g r a p h y followed b y s p a r k source m a s s s p e c t r o m e t r y which can d e t e r m i n e l a n t h a n i d e s in rocks d o w n t o c o n c e n t r a t i o n s below 0.001 p p m is d e s c r i b e d . F. W. E. Strelow and P. F . S. J a c k s o n , National Chemical Research Laboratories, CSIR, Pretoria, Republic of South Africa Anal. Chem., 46, 1481 (1974)
S e c o n d a r y I o n M a s s S p e c t r o m e t r y of R a r e E a r t h Elements T h e b e h a v i o r of t h e ionic species from various r a r e e a r t h c o m p o u n d s , t h e relative ion i n t e n s i t i e s , d e t e c t i o n limits, analytical curves, a n d precision are discussed. Toshio Ishizuka, Government Industrial Research Institute, Nagoya 1-1, Hirate-machi, Kita-ku, Nagoya, Japan Anal. Chem., 46, 1487 (1974)
Computer Controlled Rapid Scanning Stop Flow Spectrometer A s c a n n i n g k i n e t i c s p e c t r o m e t e r is d e s c r i b e d which can c o m p u t e r - a c q u i r e 2 5 0 - n m s p e c t r a of r e a c t i n g solutions in 1.20 milliseconds w i t h a r e p e t i t i o n r a t e of 2 milliseconds. R. M. Wightman, R. L. Scott, C. N. Reilley, and Royce W. M u r r a y , William Rand Kenan, Jr., Laboratories of Chemistry, University of North Carolina, Chapel Hill, N.C. 27514, and J . N . B u r n e t t , Department of Chemistry, Davidson College, Davidson, N.C. Anal. Chem., 46, 1492 (1974)
Determination of Elemental Mercury in an Emission Source Having a High Sulfur Dioxide Concentration by Amalgamation with Gold and Ultraviolet Spectrophotometry E l e m e n t a l m e r c u r y in t h e p r e s e n c e of 6 - 8 % sulfur dioxide is collected from s t a c k gases by a m a l g a m a t i o n w i t h gold. B y i n d u c t i o n h e a t i n g , t h e m e r c u r y is volatilized i n t o p o t a s s i u m p e r m a n g a n a t e solution, r e d u c e d , a e r a t e d , a n d d e t e r mined by ultraviolet spectrophotometry. C h a r l e s M. Baldeck a n d G. William Kalb, TraDet Laboratories, Inc., 930 Kinnear Road, Columbus, Ohio 43212, and H o w a r d L. Crist, Quality Assurance & Environmental Monitoring Laboratory, National Environmental Research Center, Environmental Protection Agency, Research Triangle Park, N.C. 27711 Anal. Chem., 46, 1500 (1974)
A N A L Y T I C A L CHEMISTRY, VOL. 46, NO. 11, SEPTEMBER 1974 • 859 A
Briefs Determination of Traces of Peroxides in Hydrocarbon Process Streams An iodometric method for total peroxides in pure buta1,3-diene and C4/C5 hydrocarbon streams, which eliminates interferences from cyclic and acyclic unsaturates, is described. Precision and accuracy (1-40 ppm active oxygen) is good. I. J. Thomson and G. C. Bell, Imperial Chemical Industries Limited, Petrochemicals Division, Billingham, Teesside, TS23 1JB, England Anal. Chem., 46, 1505 (1974) I n o r g a n i c P r o b e s for t h e P h o s p h o r i m e t r i c D e t e r m i n a t i o n of N u c l e o s i d e s The introduction of inorganic probes in the phosphorimetric analysis of structurally similar organic and bioorganic molecules provides a new dimension in sensitivity and selectivity. G. D. Boutilier and C. M. O'Donnell, Department of Chemistry, Colorado State University, Fort Collins, Colo. 80521, and R. O. Rahn, Biology Division, Oak Ridge National Laboratory, Oak Ridge, Tenn. 37830 Anal. Chem., 46, 1508 (1974)
Critical Evaluation of Correction Methods for Interelement Effects in X-Ray Fluorescence Analysis Applied to Binary Mixtures Different methods of correction for interelement effects in X-ray fluorescence analysis are compared and evaluated. These correction methods are applied to the determination of Cu in Cu-Fe solutions and solids. Cesia Shenberg and Saadia Amiel, Soreq Nuclear Research Centre, Yavne, Israel Anal. Chem., 46, 1512 (1974)
Simultaneous Determination of Precise EquivaL nee Points and pKa Values from Potentiometric Data: Single pif Systems Precise linear equations are developed for the potentiometric determination of equivalence points, pK, and "proton purity" of weak monobasic acids. pK's. precise to ±0.003 unit are obtainable; accuracy is limited only by the calibrating buffers. T. N. Briggs and J. E. Stuehr, Department of Chemistry, Case Western Reserve University, Cleveland, Ohio 44106 Anal. Chem., 46, 1517 (1974) Semiintegral Electroanalysis: Studies on the Neopolarographic Plateau Electrode curvature and double-layer charging contribute to the destruction of the horizontality of neopolarographic plateaus. These effects are subjected to theoretical and experimental study. Masashi Goto and Keith B. Oldham, Trent University, Peterborough, Ontario, Canada Anal. Chem., 46, 1522 (1974)
Alternating Current Linear Sweep and Stripping Voltammetry with Phase-Selective Second Harmonic Detection The present work gives a quantitative assessment of resolution and demonstrates that in both the linear sweep and stripping modes, phase-selective second harmonic ac voltammetry should provide some of the most sensitive electroanalytical methods available for reversible electrode processes. H. Blutstein and A. M. Bond, Department of Inorganic Chemistry, University of Melbourne, Parkville, Victoria 3052, Australia Anal. Chem., 46, 1531 (1974)
T h e o r e t i c a l T r e a t m e n t of t h e S e l e c t i v i t y a n d D e t e c t i o n L i m i t of S i l v e r C o m p o u n d M e m b r a n e Electrodes Equations are derived that describe the selectivity behavior and the detection limits of different solid-state membrane electrodes. Werner E. Morf, Gunter Kahr, and Wilhelm Simon, Laboratorium fur Organische Chemie der Eidgenossischen Technischen Hochschule, Zurich, Switzerland Anal. Chem., 46, 1538 (1974)
Differential Amperometric Measurement of Serum Lactate Dehydrogenase Activity Using Bindschedler's Green An amperometric method utilizing differential amperometry at tubular carbon electrodes in flowing streams is described for the measurement of human serum lactate dehydrogenase activity. Marilyn Dix Smith and Carter L. Olson, College of Pharmacy, The Ohio State University, Columbus, Ohio 43210 Anal. Chem., 46, 1544 (1974)
New Procedure for Calibrating Glass Electrodes A new method for testing glass electrodes at constant pH in the range 6.5-12.6 and pNa 0, 1, and 2 is suggested, and applied to representative commercial glass electrodes. M. Filoména G. F. C. Camoes and Arthur K. Covington, Department of Physical Chemistry, University of Newcastle upon Tyne, England Anal. Chem., 46, 1547 (1974) Alternating Current Polarographic D e t e r m i n a t i o n of U r a n i u m i n C o m p l e x M i n e r a l s C h a r a c t e r i z e d by E l e c t r o n P r o b e A n a l y s i s Complete characterization of the minerals by electron probe data and comparative work with atomic absorption spectrometry, X-ray fluorescence, and fission track analysis demonstrate the specificity and value of the method. A. M. Bond, Department of Inorganic Chemistry, University of Melbourne, Parkville, 3052, Victoria, Australia, and V. S. Biskupsky and D. A. Wark, Department of Geology, University of Melbourne, Parkville, 3052, Victoria, Australia Anal. Chem., 46, 1551 (1974) S t a n d a r d P o t e n t i a l s of S o l i d - S t a t e M e t a l I o n Selective Electrodes The standard potentials of metal ion selective electrodes of the type silver sulfide-metal sulfide are calculated from thermodynamic relations and compared with experimental values. Manfred Koebel, Orion Research, Inc., Cambridge, Mass. 02139 Anal. Chem., 46, 1559 (1974) A Turbulent Tubular Electrode The design and characteristics of a microtubular electrode in which turbulence is impressed by a spiralled strip stirrer rotating parallel to the axis of the tube are described. W. J. Blaedel and G. W. Schieffer, Department of Chemistry, University of Wisconsin, Madison, Wis. 53706 Anal. Chem., 46, 1564 (1974)
A N A L Y T I C A L CHEMISTRY, VOL. 46, NO. 1 1 , SEPTEMBER 1974 •· 861 A
Briefs Fundamental and Second Harmonic Alternating C u r r e n t P o l a r o g r a p h y of E l e c t r o d e P r o c e s s e s with Coupled First-Order Catalytic Chemical Reactions: Theory and Experimental Results with the Iron Triethanolamine-Chlorite System Experimental data supporting theoretical predictions are p r e s e n t e d for t h e previously u n r e p o r t e d c a t a l y t i c p r o c e s s w h i c h occurs w h e n ferric t r i e t h a n o l a m i n e is r e d u c e d in t h e p r e s e n c e of c h l o r i t e ion. K a t h r y n R. Bullock and Donald E. Smith, Department of Chemistry, Northwestern University, Evanston, 111. 60201 Anal. Chem., 46, 1567 (1974)
Notes D e t e r m i n a t i o n of S u l f u r D i o x i d e by A n o d i c Oxidation on Lead D i o x i d e E l e c t r o d e s E x p e r i m e n t a l r e s u l t s a r e p r e s e n t e d i l l u s t r a t i n g t h e efficiency of lead d i o x i d e e l e c t r o d e s as e l e c t r o c a t a l y s t for t h e d e t e r m i n a t i o n of sulfur d i o x i d e in air b y its a n o d i c o x i d a t i o n . Guy Bélanger, Hydro-Quebec, Institute of Research Varennes, Quebec, Canada Anal. Chem., 46, 1576 (1974) R a p i d M e t h o d f o r t h e E s t i m a t i o n of T o t a l F r e e Estrogens in Plasma A r a d i o i m m u n o a s s a y is d e s c r i b e d for t h e r a p i d e s t i m a t i o n of t h e t o t a l free e s t r o g e n c o n t e n t of blood (estrone, e s t r a diol, a n d estriol) using a n a n t i b o d y w i t h a high cross-reactivity t o all t h r e e forms. E u g e n e Cerceo a n d Cipriano Elloso, Department of Pathology, Thomas Jefferson University Hospital, Philadelphia, Pa. 19107 Anal. Chem., 46, 1578 (1974) D e t e r m i n a t i o n of B e n z o [ a ] p y r e n e i n T a r s a n d Petroleum D e t e r m i n a t i o n of 0.1 p p m b e n z o [ a ] p y r e n e is possible w i t h a c c u r a c y of ± 1 0 % using G P C , a d s o r p t i o n c h r o m a t o g r a p h y , a n d fluorescence e x c i t a t i o n s p e c t r a . Milan Popl, Michal Stejskal, a n d J i r i Mostecky, Institute of Chemical Technology, 166 28 Prague 6, Suchbâtarova 1905, Czechoslovakia Anal. Chem., 46, 1581 (1974) M e a s u r e m e n t of T r a c e A m o u n t s of H e x a f l u o r o a c e t o n e in Air by I n f r a r e d Spectrometry, after Conversion to Fluoroform H e x a f l u o r o a c e t o n e is r e a c t e d with K2CO3 a n d t h e r e s u l t i n g C H F 3 m e a s u r e d in a 7.5-cm infrared gas cell. T h e T L V of 0.1 p p m is easily d e t e c t e d . Bertsil B. B a k e r , J r . , a n d D. P e t e r Carlson, Plastics Department, E. I. du Pont de Nemours and Co., Inc., Experimental Station, Wilmington, Del! 19898 Anal. Chem., 46, 1583 (1974) D e t e r m i n a t i o n of A c e t a l d e h y d e in Glacial A c e t i c A c i d by Gas C h r o m a t o g r a p h y A g a s - l i q u i d c h r o m a t o g r a p h i c p r o c e d u r e is p r e s e n t e d for e s t i m a t i n g t h e a c e t a l d e h y d e c o n t e n t in glacial a c e t i c acid a n d is sensitive d o w n t o a p p m . H a r o l d J . Rhodes, David W. Bode, a n d M a r t i n I. Blake, College of Pharmacy, University of Illinois at the Medical Center, Chicago, 111. 60612 Anal. Chem., 46, 1584 (1974)
C o u l o m e t r i c G e n e r a t i o n of M o l y b d e n u m ( V I ) f r o m a M o l y b d e n u m E l e c t r o d e — T i t r a t i o n of Lead(II) C u r r e n t efficiencies a r e e s t a b l i s h e d as a function of p H , s u p p o r t i n g electrolyte c o n c e n t r a t i o n a n d g e n e r a t i o n t i m e . L e a d from 7 X 1 0 _ 5 M t o 1 X 1 0 _ 3 M is t i t r a t e d w i t h a n acc u r a c y of a few p a r t s p e r t h o u s a n d . G. S t e p h e n Kelsey a n d H u r d W. Safford, Department of Chemistry, University of Pittsburgh, Pittsburgh, Pa. 15260 Anal. Chem., 46, 1585 (1974) R a p i d D e t e r m i n a t i o n of F o r m a l d e h y d e by S h o r t Circuit Argentometric Amperometric Titration Using a Rotating Platinum Microelectrode A s i m p l e , a c c u r a t e , a n d sensitive m e t h o d for t h e d e t e r m i n a t i o n of f o r m a l d e h y d e is d e v e l o p e d . T h e s a m p l e is t r e a t e d w i t h p o t a s s i u m c y a n i d e , t h e n t h e excess of r e a g e n t is t i t r a t ed amperometrically. S a n a e Ikeda, Department of Chemistry, University of Connecticut, Storrs, Conn. 06268 Anal. Chem., 46, 1587 (1974) E f f e c t o f A g e of R e a c t a n t S o l u t i o n s o n t h e P r e c i p i t a t i o n of N i c k e l A m m o n i u m S u l f a t e Hexahydrate N i c k e l a m m o n i u m sulfate h e x a h y d r a t e is p r e c i p i t a t e d b y m i x i n g nickel a n d a m m o n i u m sulfate s o l u t i o n s . I t is s h o w n t h a t freshly p r e p a r e d s o l u t i o n s give longer i n d u c t i o n p e r i ods a n d s m a l l e r crystals t h a n d o aged s o l u t i o n s . H-M. Ang a n d J . W. Mullin, Department of Chemical Engineering, University College London, Torrington Place, London WCIE 7JE Anal. Chem., 46, 1588 (1974) Associations in a R e a c t i o n M i x t u r e Evidenced by Column Liquid Chromatography and Interpretation in Kinetics F r o m a n o m a l o u s b e h a v i o r of c e r t a i n r e a g e n t s in c o l u m n liquid c h r o m a t o g r a p h y , a m e t h o d is d e s c r i b e d t o s t u d y t h e i r association a n d d e t e r m i n e e q u i l i b r i u m c o n s t a n t s . A n d r é Revillon, L. A. 199, C.N.R.S., Institut de Recherches sur la Catalyse, 39, Boulevard du 11 Novembre 1918, 69100-Villeurbanne, France Anal. Chem., 46, 1589 (1974) O x y g e n - R i c h A t m o s p h e r e for D i r e c t D e t e r m i n a t i o n of C o p p e r i n O i l s b y N o n f l a m e Atomic Absorption Spectrometry R e d u c e d n i t r o g e n flow r a t e d u r i n g a t o m i z a t i o n a n d / o r d e s t r u c t i o n of t h e organic m a t r i x w i t h i n 500 ° C u n d e r oxyg e n - r i c h a t m o s p h e r e i m p r o v e s sensitivity a n d r e p e a t a b i l ity. A b s o l u t e d e t e c t i o n l i m i t for c o p p e r in oil solution is 20 X 10"12g. M. K. K u n d u a n d A. Prévôt, Institut des Corps Gras (ITERG), 5 Bid de Latour-Maubourg, 75007 Paris Anal. Chem., 46, 1591 (1974) I n v e s t i g a t i o n s on t h e Analysis of S u l f a t i o n P l a t e s E r r o r s of u p t o 3 a r e e l i m i n a t e d by r u n n i n g s a m p l e s a n d s t a n d a r d s a t t h e s a m e p H . T h e p e r c e n t recovery is signific a n t l y i n c r e a s e d t o a b o u t 90%. H u g h Y. C. See a n d I a n M. Salomon, Chemistry Laboratory, Water Resources Service, 3650 Wesbrook Crescent, Vancouver 8, B.C., Canada Anal. Chem., 46, 1595 (1974)
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Briefs D e t e r m i n a t i o n of C a d m i u m , Lead, T h a l l i u m , a n d N i c k e l in Blood by Atomic Absorption Spectrometry T h e s i m u l t a n e o u s , d i r e c t e x t r a c t i o n of Cd, P b , T l , a n d N i from blood is r e p o r t e d . T h e m e t h o d h a s a precision of b e t ter t h a n 0.0015 a b s o r b a n c e u n i t for a b s o r b a n c e s of 0.01 t o 0.12. Francis Amore Division of Laboratories, Illinois Department of Public Health, Springfield, 111. 62701 Anal. Chem., 46, 1597 (1974) Gel Permeation Chromatography: On the M e c h a n i s m of S e p a r a t i o n b y F l o w E x p e r i m e n t a l s t u d y t e n d s t o confirm a r e c e n t l y p r o p o s e d m e c h a n i s m for m o l e c u l a r s e p a r a t i o n by gel p e r m e a t i o n chromatography. Sadao Mori and Roger S. Porter, Polymer Science and Engineering, University of Massachusetts, Amherst, Mass. 01002, and Julian F. Johnson, Institute of Materials Science and Department of Chemistry, University of Connecticut, Storrs, Conn. 06268 Anal. Chem., 46, 1599 (1974) D e t e r m i n a t i o n of V i t a m i n D2 in G e l a t i n Protected Vitamin A Acetate/Vitamin D2 Beadlets by High Pressure Liquid Chromatography T h e p r o c e d u r e utilizes a c o l u m n of small d i a m e t e r silica a n d an e x t r a c t i o n p r o c e d u r e which p r o v i d e s c o m p l e t e separ a t i o n of v i t a m i n D 2 from a gelatin m a t r i x . L e n g t h y e x t r a c t i o n s are e l i m i n a t e d a n d r a p i d , reliable d e t e r m i n a t i o n s result. David F. Tomkins and Ronald J. Tscherne, Quality Control Department, Hoffmann-La Roche Inc., Nutley, N.J. 07110 Anal. Chem., 46, 1602 (1974) Spectrophotometric D e t e r m i n a t i o n of Copper(I) and Cobalt(II) with Ferrozine T h e i n e x p e n s i v e a n d w a t e r - s o l u b l e 3-(2-pyridyl)-5,6-bis(4p h e n y l sulfonic a c i d ) - l , 2 , 4 - t r i a z i n e d i s o d i u m salt, ferrozine, is u s e d in 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 c o p p e r ( I ) , c o b a l t ( I I ) , a n d c o p p e r a n d iron w h e n p r e s e n t t o g e t h e r . S. K. Kundra, Mohan Katyal, and R. P. Singh, Chemistry Department, Delhi University, Delhi 110007, and St. Stephen's College, Delhi 110007, India. Anal. Chem., 46, 1605 (1974) Perchloric Acid Procedure for Wet-Ashing Organics for the D e t e r m i n a t i o n of M e r c u r y (and Other Metals) O r g a n i c s a m p l e s weighing u p to 5 g can be w e t - a s h e d safely w i t h H N O 3 a n d HCIO4 w i t h o u t using a w a t e r - c o o l e d cond e n s e r . H i g h - l i p i d s a m p l e s m u s t first be c h a r r e d w i t h H2S04. Cyrus Feldman, Oak Ridge National Laboratory, Oak Ridge, Tenn. 37830 Anal. Chem., 46, 1606 (1974) 1,2,3-Phenyloxyamidine—A N e w T y p e of Analytical Reagent. Solvent Extraction and 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 Vanadium(V) S t u d i e s show t h a t 1,2,3-phenyloxyamidine is an excellent r e a g e n t for t h e 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 v a n a d i u m ( V ) b y s o l v e n t e x t r a c t i o n a n d for t h e g r a v i m e t r i c d e t e r m i n a t i o n of c o p p e r ( I I ) a n d nickel(II). Kodela S a t y a n a r a y a n a , Department of Chemistry, College of Science, Raipur (M.P), India, and R a j e n d r a K. M i s h r a , Department of Chemistry, Ravishankar University, Raipur (M.P), India Anal. Chem., 46, 1609 (1974)
F i n i t e D i f f e r e n c e M e t h o d s in t h e T h e o r y of Chronopotentiometry T h e usefulness of finite difference m e t h o d s in solving n o n linear c h r o n o p o t e n t i o m e t r i c e q u a t i o n s is s h o w n b y m e a n s of t w o e x a m p l e s . D. K. McCreary and P. D. Schettler, Chemistry Department, Juniata College, Huntingdon, Pa. 16652 Anal. Chem., 46, 1610 (1974)
Correspondence Loss of M e t h y l m e r c u r y - 2 0 3 f r o m W a t e r W. Dickinson Burrows, Associated Water and Air Resources Engineers, Inc., Nashville, Tenn. 37204, and Peter A. Krenkel, Environmental and Water Resources Engineering Program, Vanderbilt University, Nashville, Tenn. 37235 Anal. Chem., 46, 1613 (1974) O n t h e C o n f i d e n c e Limits o n t h e P r o d u c t of T w o Uncertain Numbers Svante Wold, Institute of Chemistry, Umeâ University, S90187 Umeâ, Sweden Anal. Chem., 46, 1614 (1974)
Aids For Analytical Chemists R a p i d M e t h o d for D e t e r m i n i n g D e n s i t i e s of Liquids Using Micro Syringes James E. Burroughs and Charles P. Goodrich, Borg-Warner Corporation, Roy C. Ingersoll Research Center, Des Plaines, 111. 60018 Anal. Chem, 46, 1614 (1974) Simple, Efficient R e d u c t i o n C o l u m n for U s e in t h e A u t o m a t e d D e t e r m i n a t i o n of N i t r a t e in Water M. P. Stainton, Canadian Department of the Environment, Freshwater Institute, 501 University Crescent, Winnipeg, Manitoba, Canada R3T 2N6 Anal. Chem., 46, 1616 (1974) M i c r o - K j e l d a h l Analysis by an I m p r o v e d Automated Ammonia Determination Following Manual Digestion J. A. Bietz, Northern Regional Research Laboratory, Agricultural Research Service, U.S. Department of Agriculture, Peoria, 111. 61604 Anal. Chem., 46, 1617 (1974) Versatile Precision Timer with Large Dynamic Range G e r t Karlsson, Institute of Biological Chemistry A, August Krogh Institute, University of Copenhagen, 13 Universitetsparken—DK 2100 Copenhagen O, Denmark Anal. Chem., 46, 1618 (1974) Simple Method for Gas Chromatographic D e t e r m i n a t i o n of Ethylene Emitted from Plant Tissues K. A. Ramsteiner, B. A. Karlhuber, and W. D. Hormann, CIBA-GEIGY Ltd., Agrochemical Division, Basel, Switzerland Anal. Chem., 46, 1621 (1974) Constant Pressure Gas Buret Michèle Forina, Institute of Analytical Chemistry, Faculty of Pharmacy, University of Genoa, Genoa, Italy Anal. Chem., 46, 1622 (1974) Facile Laboratory Method for Preparation of W e i g h e d S a m p l e s of P u r i f i e d S o d i u m M e t a l Sealed under Vacuum R. L. J o n e s and R. R. Dewald, Department of Chemistry, Tufts University, Medford, Mass. 02155 Anal. Chem., 46, 1623 (1974)
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