Briefs

Briefs Analytical Applications of X-Ray Excited Optical Luminescence. Direct Determination of Rare Earth Nuclear Poisons in Zirconia

P l a s m a C h r o m a t o g r a p h y of N o r m a l A l k a n e s a n d I t s R e l a t i o n s h i p to C h e m i c a l I o n i z a t i o n M a s s Spectrometry Similarities between the plasma chromatographic mobility spectra of the n-alkanes and n-alkyl halides and their chemical ionization mass spectra are compared. Francis W. Karasek, Donald W. Denney, and Edward H. DeDecker, Department of Chemistry, University of Waterloo, Waterloo, Ontario Anal. Chem., 46, 970 (1974)

The "neutron poisons" Gd, Sm, Eu, and Dy are directly determined at the fractional ppm level in nuclear grade Z1O2 and Zircaloys by the optical luminescence emitted under X-ray excitation. Arthur P. D'Silva and Velmer A. Fassel, Ames LaboratoryUSAEC and Department of Chemistry, Iowa State University, Ames, Iowa 50010 Anal. Chem., 46, 996 (1974)

G a s C h r o m a t o g r a p h i c S t u d y of ^ - C o m p l e x e s of Hexenes with Palladium Dichloride and Silver(I) From the retention data of eight hexenes on PdCl2- or AgN03-iV-methylacetamide, the stability constants of the originating complexes are calculated and discussed in terms of the differences of their structure and the stationary phases' selectivity. Milan Kraitr, Pedagogical Institute, Plzen, 306 19, Czechoslovakia, and Radko Komers, Institute of Chemical Process Fundamentals, Czechoslovak Academy of Sciences, Prague-Suchdol, 165 02, Czechoslovakia, and Frantisek Cuta, Institute of Chemical Technology, Prague, 166 28, Czechoslovakia Anal. Chem., 46, 974 (1974)

Hadamard Spectrometer for Ultraviolet-Visible Spectrometry A Hadamard Transform Spectrometer, recording spectra over a range of 25 nm in about 25 seconds, is constructed and used in the UV-Visible spectral region. F. W. Plankey, T. H. Glenn, L. P. Hart, and J. D. Winefordner, Department of Chemistry, University of Florida, Gainesville, Fla. 32611 Anal. Chem., 46, WOO (1974)

Determination of Zinc and Cadmium in Environmentally Based Samples by the Radiofrequency Spectrometric Source The capability of the radiofrequency furnace spectrometric source to analyze Cd and Zn at the concentration range of 0.006-130 ppm in environmentally based samples is demonstrated. Average accuracy is 6.8% and reproducibility is 5.5%. Yair Talmi, Analytical Chemistry Division, Oak Ridge National Laboratory, Oak Ridge, Tenn. Anal. Chem., 46, 1005 (1974)

G a s C h r o m a t o g r a p h i c D e t e r m i n a t i o n at t h e P a r t s - p e r - M i l l i o n Level of A l i p h a t i c A m i n e s in Aqueous Solution Quantitative determinations of aliphatic amines in aqueous solution at sub-ppm levels are performed with the use of suitably modified graphitized carbon blacks. Antonio Di Coreia and Roberto Samperi, Istituto di Chimica Analitica, Université di Roma, 00185 Roma, Italy Anal. Chem., 46, 977(1974)

Luminescence Properties of Sulfonamide Drugs The effects of solvent, pH, and substituents on sulfonamide fluorescence and phosphorescence are discussed. Sulfonamides in serum are estimated fluorimetrically at therapeutic dosage levels with 2-7% coefficients of variation. J. W. Bridges, Department of Biochemistry, University of Surrey, Guildford, England, and L. A. Gifford, W. P. Hayes, J. N. Miller, and D. Thorburn Burns, Department of Chemistry, Loughborough University of Technology, Loughborough, LE11 3TU, England Anal. Chem., 46, 1010 (1974)

Correlation of R e t e n t i o n V o l u m e s of S u b s t i t u t e d Carboranes with Molecular Properties in High P r e s s u r e Liquid C h r o m a t o g r a p h y U s i n g F a c t o r Analysis The LC retention volumes of a series of carborane compounds are correlated with their molecular properties. Also, a method for distinguishing between the class under study and unlike contaminants is presented. John H. Kindsvater, Paul H. Weiner, and Theodore J. Klingen, Department of Chemistry, The University of Mississippi, University, Miss. 38677 Anal. Chem., 46, 982 (1974)

Analytical Reactions Involved in the Spectrophotometry Determination of Alkylaluminum Compounds Using Isoquinoline

D e t e r m i n a t i o n of O p t i m a l S o l v e n t C o m p o s i t i o n in T h i n L a y e r C h r o m a t o g r a p h y by M e a n s of Numerical Analysis Numerical analysis is used for the calculation of the optimal ratio of the components in a TLC developing solvent system. Experiments planned for this purpose produce the necessary data. S. Turina and M. Trbojevic, Institute for Material Research, University of Zagreb, Djure, Salaja 1, Yugoslavia, and M. Kastelan-Macan, Institute for Inorganic and Analytical Chemistry, University of Zagreb, Yugoslavia Anal. Chem., 46, 988 (1974) 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 Iron in A c i d s a n d A c i d i c S o l u t i o n s by a n E x t r a c t i o n F o r m a t i o n R e a c t i o n I n v o l v i n g 3-(2-Pyridyl)-5,6d i p h e n y l - l , 2 , 4 - t r i a z i n e a s the C h r o m o g e n i c Extraction Reagent A method for the direct determination of iron at ppb levels in acids and acidic solutions is described.

The analytically important products of the reaction of isoquinoline with diethylaluminum hydride and triethylaluminum are characterized using NMR. George W. Heunisch, Research and Development Department, Continental Oil Company, Ponca City, Okla. 74601 Anal. Chem., 46, 1018 (1974)

Wear Metal Determination by Plasma Jet Direct Current Arc Spectrometry A spectrographic method developed for the determination of wear metals in used oils by means of the plasma jet dc arc uses a direct force-feeding approach to overcome sampling problems. P. M. McElfresh and M. L. Parsons, Department of Chemistry, Arizona State University, Tempe, Ariz. 85281 Anal. Chem., 46, 1021 (1974)

C. D. Chriswell and A. A. Schilt, Department of Chemistry, Northern Illinois University, DeKalb, 111. 60115 Anal. Chem., 46, 992 (1974) A N A L Y T I C A L CHEMISTRY, VOL. 46, NO. 8, JULY 1974 • 685 A

Briefs Immobilized E n z y m e Electrode for the F l u o r e s c e n c e D e t e c t i o n of Sulfur D i o x i d e i n Air D e t e r m i n a t i o n of A r g i n a s e a t the P a r t s per B i l l i o n Level Experimental details of the preparation and utilization of A sensitive SO2 detector based on a fluorescence method an urease immobilized enzyme electrode suitable for the is described. The response is linear from low ppb to a few determination of arginase are presented. Criteria for furppm of SO2 in air with little interference from the water vapor. ther applications of the electrode are given. H. Edward Booker and John L. Haslam, Department of ChemFrederick P. Schwarz and Hideo Okabe, Physical Chemistry istry, University of Kansas, Lawrence, Kan. 66044 Division, National Bureau of Standards, Washington, D.C. 20234, and Julian K. Whittaker, Nuclear Sciences Division, National Anal. Chem., 46, 1054(1974) Bureau of Standards, Washington, D.C. 20234 Anal. Chem., 46, 1024 (1974) A b s o l u t e D e t e r m i n a t i o n of A t m o s p h e r i c H a l o c a r b o n s by G a s P h a s e Coulometry A gas chromatograph equipped with two electron capture T e m p e r a t u r e Controlled H e a t i n g of the Graphite detectors in series is used to measure ambient halocarbons T u b e A t o m i z e r i n F l a m e l e s s A t o m i c Absorption coulometrically. The inherent sensitivity and absolute naSpectrometry ture of this method promise wide application. Optimized temperature for atomization of Pb and Cd is Daniel Lillian and Hanwant Bir Singh, Department of Envi1060 °C and 820 °C, respectively. For Ce, no depressive ronmental Sciences, Rutgers University—The State University of effect is observed when NaCl at sea water concentration is New Jersey, New Brunswick, N.J. 08903 present. Anal. Chem., 46, 1060 (1974) Gillis Lundgren, Lars Lundmark, and Gillis Johansson, Department of Analytical Chemistry, University of Umeà, 901 87 D i r e c t Current, A l t e r n a t i n g Current, P u l s e , a n d Umeà, Sweden Anal. Chem., 46, 1028 (1974) Anodic S t r i p p i n g V o l t a m m e t r i c M e t h o d s w i t h G l a s s y Carbon E l e c t r o d e s in Hydrofluoric Acid The use of glassy carbon electrodes is described. A comT i m e - R e s o l v e d D i s t r i b u t i o n of A t o m s i n parison of a wide variety of electroanalytical techniques Flameless Spectrometry. A Theoretical indicates that pulse voltammetry is generally likely to be Calculation the most sensitive and reliable method. A simplified model for the release of atoms with a flameA. M. Bond, T. A. O'Donnell, and R. J. Taylor, Department of less rod atomizer is presented; the time-dependent distriInorganic Chemistry, University of Melbourne, Parkville 3052, bution of atoms in the optical beam is derived and the inVictoria, Australia Anal. Chem., 46, 1063 (1974) fluence of the parameters controlling the process is evaluated. Fundamental and Second Harmonic Alternating Stefano L. Paveri-Fontana, Istituto di Meccanica Razionale, Current P o l a r o g r a p h y of Electrode P r o c e s s e s Université di Bari, Via Nicolai, 2-70121 Bari, Italy, and Gino w i t h Coupled F i r s t - O r d e r P r e c e d i n g C h e m i c a l Tessari and Giancarlo Torsi, Istituto di Chimica Analitica, R e a c t i o n s : E x p e r i m e n t a l S t u d y of the C a d m i u m Université di Bari, Via G. Amendola, 173-70126 Bari, Italy Anal. Chem., 46, 1032 (1974) N i t r i l o t r i a c e t a t e S y s t e m Fundamental and second harmonic ac polarographic measurement results are reported for the reduction of the cadC h e m i c a l I n f o r m a t i o n from C o m p u t e r - P r o c e s s e d mium-nitrilotriacetate complex at the mercury-aqueous H i g h R e s o l u t i o n M a s s S p e c t r a l D a t a . Correction solution interface. of I n t e n s i t i e s a n d Conversion from Isotopic Kathryn R. Bullock and Donald E. Smith, Department of S p e c i e s to E q u i v a l e n t C h e m i c a l S p e c i e s Chemistry, Northwestern University, Evanston, 111. 60201 A significant reduction and clarification of computer-proAnal. Chem., 46, 1069(1974) cessed mass spectral data is achieved by the use of isotopic analysis. D e t e r m i n a t i o n of Chlordiazepoxide Hydrochloride Richard M. Hilmer and James W. Taylor, Department of (Librium) a n d Its Major M e t a b o l i t e s in P l a s m a by Chemistry, University of Wisconsin, Madison, Wis. 53706 Differential P u l s e P o l a r o g r a p h y Anal. Chem., 46, 1038 (1974) A specific differential pulse polarographic assay is described for the determination of chlordiazepoxide and its S t u d i e s of E x c h a n g e R e a c t i o n s I n v o l v i n g iV-desmethyl and lactam metabolites in plasma with an Electrogenerated Mercurous Halide Films overall recovery of 61.9% ± 3.1 (std dev), 62.0% ± 3.7 (std dev), and 62.7% ± 4.3 (std dev), respectively. The anodic deposition and cathodic dissolution of halide mixtures at the hanging mercury drop electrode (HMDE) M. R. Hackman, M. A. Brooks, and J. A. F. de Silva, Department of Biochemistry and Drug Metabolism, Hoffmann-La Roche are investigated. Heterogeneous exchange reactions at the Inc., Nutley, N.J. 07110, and T. S. Ma, Department of Chemistry, solution-electrode interface provide insight into the mechCity University of New York, Brooklyn, N.Y. 11210 anisms of film formation and alterations at the electrode. Anal. Chem., 46, 1075 (1974) G. Colovos, G. S. Wilson, and J. L. Moyers, Atmospheric Analysis Laboratory, Department of Chemistry, University of Arizona, Tucson, Ariz. 85721 Anal. Chem., 46, 1045 (1974) Internal N o r m a l i z a t i o n T e c h n i q u e s for H i g h A c c u r a c y Isotope D i l u t i o n A n a l y s e s — A p p l i c a t i o n to M o l y b d e n u m a n d N i c k e l in S t a n d a r d R e f e r e n c e 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 of B r o m i d e and Materials Chloride by Cathodic S t r i p p i n g V o l t a m m e t r y General internal normalization equations and iteration By taking advantage of electrode interfacial phenomena, techniques are developed for the high accuracy isotope it is possible to measure bromide concentrations as low as dilution analysis of Mo and Ni. Mass spectrometric and about 10~ 6 M in solutions where the chloride concentrachemical procedures are described. tion exceeds the bromide by as much as 200 times. L. J. Moore, L. A. Machlan, W. R. Shields, and E. L. Garner, G. Colovos, G. S. Wilson, and J. L.' Moyers, Atmospheric AnalAnalytical Chemistry Division, Institute for Materials Research, ysis Laboratory, Department of Chemistry, University of Arizona, National Bureau of Standards, Washington, D.C. 20234 Tucson, Ariz. 85721 Anal. Chem., 46, 1051 (1974) Anal. Chem., 46, 1082 (1974) ANALYTICAL CHEMISTRY, VOL. 46, NO. 8, JULY 1974 • 687 A

Briefs Some Analytical Applications of Reaction-RatePromoting Effects. The Tris(l,10phenanthroline)iron(II)-chromium(VI) Indicator Reaction

P u r i t y of R a d i o l a b e l e d C h e m i c a l s Examination of over 360 radiochemicals revealed 3.3% er­ rors due to mislabeling. A quality control program to de­ termine purity of radiolabeled chemicals is described. Edward J. Merrill and Arnold D. Lewis, Department of Ana­ lytical/Physical Chemistry, Warner-Lambert Research Institute, Morris Plains, N.J. 07950 Anal. Chem., 46, 1114 (1974)

Initial rate measurements are applied to obtain quantita­ tive analytical data from transient rate effects. Microgram amounts of oxalic acid, citric acid, vanadium(IV), hexacyanoferrate(III), arsenic(III), and chromium(VI), and milli­ gram amounts of molybdenum(VI) are determined. V. V. S. Eswara Dutt and Horacio A. Mottola, Department of Chemistry, Oklahoma State University, Stillwater, Okla. 74074 Anal. Chem., 46, 1090(1974)

S t u d i e s on S e v e r a l U r a n y l O r g a n o p h o s p h o r u s C o m p o u n d s i n a P o l y ( V i n y l Chloride) ( P V C ) M a t r i x a s Ion S e n s o r s for U r a n i u m Uranyl ion sensing electrodes which exhibit near Nernstian response, in the pH range 2 to 3.5, to uranyl ion ac­ tivities from about 10~ 4 to 10" 1M, are investigated. Addi­ tional studies are conducted on the most favorable elec­ trodes. D. L. Manning, J. R. Stokely, and D. W. Magouyrk, Analyti­ cal Chemistry Division, Oak Ridge National Laboratory, Oak Ridge, Tenn. 37830 Anal. Chem., 46, 1116 (1974)

Plasma and Blood Coagulation Time Detector Based on the Flow Sensitivity of Self-Heated Thermistors

The variable time approach to kinetic analysis is applied to the measurement of plasma clotting time through the use of a novel clot detector utilizing a self-heated thermis­ tor in a forced flow field. D e t e r m i n a t i o n of D i p h e n y l h y d a n t o i n b y William D. Bostick and Peter W. Carr, Department of Chem­ Phosphorescence Spectrometry istry, University of Georgia, Athens, Ga. 30602 Anal. Chem., 46, 1095 (1974) A previously described clinical technique for the determi­ nation of diphenylhydantoin (DPH) in plasma is modified to use phosphorescence spectrometry. The limit of detec­ Notes tion is 0.05 /ig/ml. Lee D. Morrison and C M . O'Donnell, Department of Chemis­ try, Colorado State University, Fort Collins, Colo. 80521 Anal. Chem., 46, 1119(1974)

Polarographic Microdetermination of Cobalt, Nickel, and Antimony in Organic Compounds Determination of Co, Ni, or Sb in organic compounds using polarography gives results accurate to within ±0.36, ±0.24, and ±0.44, respectively. The method seems appli­ cable to determination of Co and Ni in petroleum. S. W. Bishara, Y. A. Gawargious, and Β. Ν. Faltaoos, Microanalytical Research Laboratories, National Research Centre, Dokki, Cairo, Egypt Anal. Chem., 46, 1103 (1974)

Determination of Lead at the Parts per Billion Level by Cathodic Stripping Analysis This method, developed for the determination of lead in environmental samples, can detect lead in the 0 to 100 ppb range with a relative standard deviation of ±1.8 ppb. J. T. Kinard and R. C. Propst, Savannah River Laboratory, E. I. du Pont de Nemours and Co., Aiken, S.C. 29801 Anal. Chem., 46, 1106(1974)

Automated Serum Urea Determination Using Membrane Electrodes Rapid flow analysis of urea in biological fluids is accom­ plished with an automated system employing an ammonia sensing gas electrode. R. A. Llenado and G. A. Rechnitz, Department of Chemistry, State University of New York, Buffalo, N.Y. 14214 Anal. Chem., 46, 1109(1974)

Nitrogen Determination in Biological Materials by the Nuclear Track Technique The nitrogen content of SRM 1571 orchard leaves and SRM 1577 bovine liver is determined by the nuclear track technique and compared with values obtained using the Kjeldahl method. B. Stephen Carpenter and Philip D. LaFleur, Activation Anal­ ysis Section, Analytical Chemistry Division, National Bureau of Standards, Washington, D.C. 20234 Anal. Chem., 46, 1112(1974)

R e a c t i o n of t h e R a r e E a r t h E l e m e n t s w i t h Arsenazo-p-N02 Reagent The color reaction of individual rare earth elements is in­ vestigated spectrophotometrically. The sensitivities are different and molar absorptivities decrease from lantha­ num to lutetium. A. A. Muk and M. B. Pravica, Boris Kidric Institute—Vinta, Beograd, Yugoslavia Anal. Chem., 46, 1121 (1974) E m i s s i o n S p e c t r o g r a p h i c D e t e r m i n a t i o n of T r a c e E l e m e n t s in Airborne P a r t i c u l a t e M a t t e r A technique for the determination of Be, Bi, Cd, Cr, Cu, Mn, Ni, Pb, Sn, Ti, V, and Zn is described. The relative standard deviation is 13% or less. Akiyoshi Sugimae, Environmental Pollution Control Center, Osaka Pref., 1-chome, Nakamichi, Higashinari-ku, Osaka, Japan Anal. Chem., 46, 1123 (1974) A n a l y s i s of M i c r o m e t e r - S i z e P a r t i c l e s of M a g n e s i u m O x i d e a n d M a n g a n e s e D i o x i d e in Low Rise-Velocity, L a m i n a r F l a m e s A burner system and calibration procedure is described for the analysis of micrometer-size particles of MgO and Mn02 in oxycyanogen and nitrous oxide-acetylene flames. Richard D. Sacks and John R. Rentner, Department of Chem­ istry, University of Michigan, Ann Arbor, Mich. 48104 Anal. Chem., 46, 1125 (1974) i A p p l i c a t i o n of E l e c t r o n S p i n R e s o n a n c e a n d E l e c t r o n i c S p e c t r o s c o p y to t h e C h a r a c t e r i z a t i o n of V a n a d i u m S p e c i e s i n P e t r o l e u m F r a c t i o n s Electron spin resonance and visible spectroscopy are used to characterize five vanadium-containing fractions from crude petroleum. ESR parameters are shown to reflect the porphyrin/non-porphyrin composition and are confirmed by visible spectroscopic data. Frank E. Dickson and Leonidas Petrakis, Gulf Research and Development Company, Pittsburgh, Pa. 15230 Anal. Chem.. 46. 1129(1974)

A N A L Y T I C A L CHEMISTRY, VOL. 46, NO. 8, JULY 1974 • 689 A

Briefs S p e c t r o p h o t o m e t r y D e t e r m i n a t i o n of Copper in Fertilizer w i t h N e o c u p r o i n e The neocuproine method is modified to determine copper in EDTA fertilizer extract. Absorbance is measured in a mixture of water and 2-propanol. Interference of EDTA and nitrate is eliminated by addition of Zn(II) and 2-propanol, respectively. E. R. Larsen, The Inspectorate of Fertilizers, Lottenborgvej 24, DK-2800 Lyngby, Denmark Anal. Chem., 46, 1131 (1974)

Ion E x c h a n g e M e t h o d for t h e D e t e c t i o n of Aliphatic and Aromatic Aldehydes Detection is based on the formation of cyanohydrins. The ion-exchange resin in H+ form catalyzes the acid hydrolysis of cyanohydrin to the corresponding acid and ammonia. Saidul Zafar Qureshi, M. S. Rathi, and Shahana Bano, Department of Chemistry, Aligarh Muslim University, Aligarh, India Anal. Chem., 46, 1139 (1974)

James J. Campion, Department of Chemistry, State University College at New Paltz, New Paltz, N.Y. 12561 Anal. Chem., 46, 1145 (1974)

Automatic Timing of the Spectrophotometric Iodometric T i t r a t i o n Using the Leco Sulfur Determinator Boris Nebesar and J. V. Krzyzewski, Department of Energy, Mines and Resources, Mines Branch, 555 Booth Street, Ottawa, Ontario, K1A 0G1, Canada Anal. Chem., 46, 1148 (1974)

Simple Hydrogen Sulfide T r a p for the Gutzeit Arsenic D e t e r m i n a t i o n G. M. Crawford and Oscar Tavares, El Paso City-County Health Department, El Paso, Texas 79901 Anal Chem., 46, 1149(1974)

Regeneration of Used Molecular S e p a r a t o r for the Gas C h r o m a t o g r a p h — M a s s Spectrometer Method by Microwave P l a s m a Shozo Toda, Kazuyuki Aizawa, Nobutaka Takahashi, and Keiichiro Fuwa, Department of Agricultural Chemistry, University of Tokyo, Bunkyo-ku, Tokyo, 113. Japan Anal. Chem., 46, 1150(1974)

Colorimetric D e t e r m i n a t i o n of S o m e I s o x a z o l e Amines with Sodium-Naphthoquinone-4Sulfonate A statistical analysis of five determinations for each amine shows a relative standard deviation of 2.6% at a concentration of 1 x 10~ 7 Mfor 5-amino-3,4-dimethylisoxazole, 0.5% at 6 X 10 7 Mfor 4-amino-3,5-dimethylisoxazole and 2.7% at 1 X 10~ 5 Mfor 3-amino-5-methylisoxazole. R. H. Manzo, Pablo Catania, and Maria Martinez de Bertorello, Departamento de Farmacia, Facultad de Ciencias Qui micas, Universidad Nacional de Cordoba, Cordoba, Argentina Anal. Chem., 46, 1141 (1974)

The Boltzmann Distribution and the Detection L i m i t s of F l a m e E m i s s i o n

Photoelectron Spectrometric Confirmation of the Oxidation S t a t e of Copper in So-Called Secondary Copper(II) Dithizonate

Aids for Analytical Chemists

S u p p o r t - B o n d e d P h a s e s for G a s C h r o m a t o g r a p h y D e r i v e d from A l k y l a n d P h e n y l C h l o r o s i l a n e s Gas-chromatographic packing materials derived from aromatic trichlorosilanes are stable to 350 °C. On changing the substituent attached to the benzene ring, there are significant differences in retention data for the solutes. A. H. Al-Taiar, J. R. Lindsay Smith, and D. J. Waddington, Department of Chemistry, University of York, Heslington, York Y01 5DD, England Anal. Chem., 46, 1135 (1974)

Correspondence

H. G. McAdie, Ontario Research Foundation, Sheridan Park, Mississauga, Ontario, Canada L5K 1B3 Anal. Chem., 46, 1146(1974)

Pat Brand and Henry Freiser, Department of Chemistry, University of Arizona, Tucson, Ariz. 85721 Anal. Chem., 46, 1147(1974)

Model for C o m p e t i t i v e B i n d i n g A s s a y s — T h e S h a p e a n d L o c a t i o n of t h e I n h i b i t i o n C u r v e s Simple equations describing competitive binding are presented. The problem of sample identity is considered in relation to shape of the inhibition curves, both for homogeneous and heterogeneous binding. Donald J. Laurence and Graeme Wilkinson, Institute of Cancer Research, Chester Beatty Research Institute, Fulham Road, London SW3 6JB, England Anal. Chem., 46, 1132 (1974)

Differential K i n e t i c A n a l y s i s of C a t i o n s — T h e Continuous pH-Variation Method Kinetic detection of metal complexes with very different pH dependent rates of ligand exchange is performed by means of a continuously decreasing pH, induced by a chemical reaction. J. G. Kloosterboer, Philips Research Laboratories, Eindhoven, The Netherlands Anal. Chem., 46, 1143 (1974)

Recommendations for R e p o r t i n g T h e r m a l Analysis D a t a . T h e r m o m e c h a n i c a l Techniques

Device for the Automatic Compensation of C u r r e n t T r a n s d u c e r and I n t e g r a t o r E r r o r s for Chronocoulometry and Related Techniques W. S. Woodward, T. H. Ridgway, and C. N. Reilley, The William R. Kenan, Jr., Laboratories of Chemistry, University of North Carolina, Chapel Hill, N.C. 27514 Anal. Chem., 46, 1151 (1974)

N e w S a m p l i n g Device for the Recovery of Petroleum Hydrocarbons and F a t t y Acids from Aqueous Surface Films Russell Miget, Howard Kator, and Carl Oppenheimer, Marine Science Institute, University of Texas, Port Aransas, Texas 78373, and John L. Laseter and Enoch J. Ledet, Department of Biological Sciences, Louisiana State University in New Orleans, New Orleans, La. 70122 Anal. Chem., 46, 1154 (1974)

Digital Solid-State Transistorized A p p a r a t u s for Analytical M e a s u r e m e n t s Athos Bellomo, Alessandro De Robertis, Agatino Casale, and Domenico De Marco, Institute of Analytical Chemistry, University of Messina, Messina, Italy Anal. Chem., 46, 1158 (1974)

Use of a Microwave Oven in In-Process Control James A. Hesek and Robert ,C. Wilson, Analytical Services, J. T. Baker Chemical Company, Phillipsburg, N.J. 08865 Anal. Chem., 46, 1160(1974)

A N A L Y T I C A L CHEMISTRY, VOL. 46, NO. 8, JULY 1974 • 691 A