ANALYTICAL
CHEMISTRY
JULY
1 955
•
NEWS
Reaction Rates — Key to N e w Analytical Methods r
I THE BOLE
of reaction
r a t e s in
the
J- practice of analytical chemistry was featured a t t h e a n n u a l S u m m e r Sym posium sponsored b y t h e ACS Division of Analytical C h e m i s t r y a n d A N A L Y T I CAL CHEMISTRY. Strictly speaking,
microbiological a n d enzymatic bioassay methods a n d certain catalytic m e t h o d s are the only types in which t h e m e t h o d is based upon reaction rates. However, the s t u d y of t h e physical conditions under which certain reactions involving; precipitation yield pure compounds free of t h e media in which t h e y a r e formed has been i m p o r t a n t t o analysis, a n d future studies will continue to contribute useful d a t a . T h e speakers presented a s u m m a r y of t h e i m p o r t a n t findings t o date. Held a t Syracuse University, J u n e 17 a n d 18, t h e symposium a t tracted a b o u t 150 registrants. P r o g r a m chairman was T h o m a s S. Lee a n d local chairman was Louis Gordon. T h e papers will be considered for publication in t h e N o v e m b e r issue of ANALYTICAL C H E M I S T R Y . A brief a b s t r a c t of each
paper follows. Friday, J u n e 17, 1955 Rates,
Mechanisms,
and the
KDWAED S. A M I S , U n i v e r s i t y
of
Solvent. Arkansas,
Fayetteville, Ark. Brief mention was m a d e of t h e d e t e r m i nation of t h e concentrations of ions b y their catalytic effect "upon reaction r a t e s . A small a m o u n t of space was also devoted t o t h e use of t h e kinetic approach in determining t h e time limitations upon t h e use of a fading colored complex for t h e d e t e r m i n a t i o n of t h e concentration of a substance a n d in establish ing t h e stability of a color-forming reagent. T h e application of r a t e processes t o t h e deter mination of t h e concentration as a function of t i m e of r e a c t a n t s a n d p r o d u c t s w a s discussed briefly. T h e major portion of t h e p a p e r w a s devoted t o t h e discussion of r a t e s between dif ferent charge t y p e s of r e a c t a n t s as influenced by t h e ionic strength a n d dielectric constant of t h e medium. T h e use of t h e s e influences in t h e ehicidation of mechanisms was pointed out in conjunction with t h e r a t e discussion. I n conclusion, a short discussion -was given concerning t h e possibility of selective sol v a t i o n of solute particles a n d t h e influence this p h e n o m e n o n might h a v e u p o n t h e micro scopic dielectric c o n s t a n t in t h e i m m e d i a t e vicinity of t h e particle. Several specific examples of t h e application of electrostatics t o t h e i n t e r p r e t a t i o n of r a t e s a n d mechanisms were presented.
Kinetic Behavior of Halide Complexes R e lated to Analytical P r o b l e m s . H . M . NEUMANN, Northwestern University, E v a n s t o n , 111. T h e material presented centered primarily around t h e stepwise hydrolysis of halide complexes. T h e equilibrium and kinetic as pects of t h e problem could invariably be studied by use of spectrophotometric m e t h ods, since these complexes exhibited a "charge-transfer" absorption in t h e u l t r a violet. F o r certain complexes extraction a n d polarographic m e t h o d s m a y also be used. Hydrolysis of a complex of t h e t y p e MX„,~n m a y lead t o t h e formation of ions of the type Μ ( Ο Η ) Χ „ _ Γ » , ikf(OH)2Xm_2-'\ etc., or ions of t h e t y p e Μ{ΉιΟ)Χ,η-ι^η+1, Μ ( Η 2 0 ) 2 Χ „ . „ s - » + 2 , etc. T h e t y p e of h y d r o lytic species formed b y a particular m e t a l could be determined b y m e a s u r e m e n t of t h e hydrogen ion dependence of both t h e forward a n d reverse rates. Although most halide complexes reacted rapidly, t h e r e are t w o t y p e s of complexes hydrolyzing a t measurable r a t e s : (1) " i n n e r o r b i t a l " complexes a n d (2) " o u t e r o r b i t a l " complexes having considerable covalent character t o t h e m e t a l halide bond. Some of t h e mechanistic features of t h e hydrolysis of complexes of t h e latter t y p e were a p p a r e n t from a study of t h e kinetics of t h e hydrolysis of SbCls". Particularly n o t e w o r t h y was t h e acceleration of t h e reaction b y hydrogen ion and by Lew~is acids. Since t h e extraction of halide complexes b y organic solvents was of analytical i m p o r t a n c e , t h e s t r u c t u r a l features leading t o extraction were compared t o those s t r u c t u r a l features leading t o slow r a t e s of reaction. T h e utilization of both extraction d a t a a n d kinetic d a t a in identifying ionic species in solution was d e m o n s t r a t e d b y d a t a on t h e hydrolysis of SbClo" a n d SnCle , a n d b y evidence r e lating t o t h e chloro complexes of a s t a t i n e . Determination of Vanillin in t h e P r e s ence of Acetovanillone B a s e d on Competing R a t e s of Oximation. L. F O W L E K , H . R . K L I N E , AND R. S. M I T C H E L L , J o h n F . Q u e e n y
P l a n t , M o n s a n t o Chemical Co., St. Louis, Mo. T h e general m e t h o d for t h e analysis of mixtures of compounds based on differences in r a t e s of reaction with a c o m m o n reagent was briefly described. A particular utility of this m e t h o d lay in t h e analysis of mixtures of organic compounds containing a c o m m o n functional group. Conditions were de scribed under which it was possible t o resolve a two-component mixture with t w o measure m e n t s a n d t h e aid of a, calibration curve. This curve could be calculated or found ex perimentally. Depending on t h e r a t i o of the r a t e constants, o p t i m u m times a n d expected accuracies of d e t e r m i n a t i o n s could be esti mated. An example was shown in t h e d e t e r m i n a tion of vanillin in concentrates obtained from t h e oxidation of alkaline lignosulfonates. T h e major i m p u r i t y w a s acetovanillone. A volumetric oximation method with control of t h e t e m p e r a t u r e (0 to 5° C.) a n d t h e t i m e of reaction (3 t o 9 minutes) enabled a n accuracy of 0 . 5 % t o be attained in t h e presence of u p t o 3 0 % acetovanillone a n d of other n o n c a r b o n y l impurities. R a p i d i t y a n d simplicity m a k e t h e method highly useful. T h e reaction mechanism a n d kinetics (second order, general acid catalyzed) were genera] for carbonyl compounds with this t y p e of reagent. T h e large differences in reaction rates for aldehydes a n d ketones indi cated t h a t t h e m e t h o d could be extended t o other mixtures. T h e U s e of Microorganisms a s Analytical Tools.
D A L E A. H A R R I S , M e r c k & Co., Inc.,
Rahway, N. J T h e paper dealt with a general review of t h e use of microorganisms for t h e assay of antibiotics, vitamins, a n d amino acids. T h e general requirements necessary for t h e per formance of t h e various t y p e s of assays were outlined. These included i n t r o d u c t o r y r e m a r k s on bioassays in general, t h e n a t u r e a n d handling of t h e microorganisms involved, t h e culture media utilized, t h e influence, where i m p o r t a n t , of such factors as carbon dioxide,
Fine weather in Syracuse made possible outdoor registration for the Summer Analytical Symposium
I n d u c e d Reactions in Analytical C h e m i s try.
A V R O M I . M E D A L I A , Boston
University,
Boston, M a s s . T h e significance of induced reactions in analytical chemistry was discussed. I t was shown t h a t an u n d e r s t a n d i n g of t h e mech anism of a reaction was i m p o r t a n t in deter mining i t s scope a n d t h e effect of interfering substances. Examples were d r a w n from r e actions of analytical significance of which t h e mechanisms h a d been recently elucidated.
VOLUME
2 7, N O . 7, J U L Y 1 9 5 5
23 A
NEWS BEFORE VERSENE This photo shows a beaker filled with water containing iron as insoluble ferric hydroxide.Thesolutionisopaque.
AFTER VERSENE This photo shows the same identical beaker and contents several minutes later after one of the Versene products (Versene-T) has been added. The solu-/ tion is now crystal clear.
oxygen, pH, and temperature, the calculation of assay results, and the sensitivity and re producibility of the various assays. It in cluded a discussion of the various micro biological assay techniques including serial dilution, diffusion, turbidimetric, titrimetric, and other miscellaneous metabolic activity methods. It was shown where each tech nique was most widely used for the various analyses of antibiotics, vitamins, and amino acids. Where applicable, the effect of rates, as they pertain to biological systems im portant in microbiological assays, was pointed out. In addition, the use of bioassays in chemical, stability, biological standardization, nutritional, and micro biological studies was described. The Identification of Short-Lived Species in Chemical Reactions.
EDWIN W. ABRA-
HAMSON, New York State College of Forestry, Syracuse, Ν. Υ.
how to solubilise INSOLUBLES
Versene
®
ΦΦ
The participation of short-lived interme diates in chemical reactions was generally in ferred from kinetic studies. These inter mediate species were usually atoms or radi cals whose steady state concentrations in chemical reactions were too small to be measured by conventional methods. The identification of short-lived inter mediates required their spontaneous genera tion in high concentration. This has been solved in large measure by the recent de velopment of the Shockwave and flash photol ysis techniques. When these techniques are coupled with rapid spectroscopic meth ods, it is possible to measure not only the absorption spectra of the species but their lifetimes as well. High concentrations of short-lived species could also be achieved by the irradiation of reactants dissolved in solvents frozen to rigid glasses. In this rigid glassy state, the atoms or radicals produced by irradiation remained stabilized indefinitely since bimolecular reactions involving them were strongly inhibited. Thus, the spectra of these stabilized species could be measured by conventional spectrophotometric tech niques. Saturday, June 18, 1955
SEEING IS BELIEVING
The illustrations give you a visible demonstration of Versene's chelating power over metals in solution. Versene makes them vanish. They are still present b u t can no longer be seen or detected by ordinary chemical procedures. Stability is inherent and reversion does not occur. This is because chelation is complete and the metallic ions are held harmless in t h e powerful coordinate bonds of t h e Versene itself. VERSENE — K E Y TO CHELATION
Versene is your key to chelation. When faced with a problem in metal ion control call on t h e Versene best designed to help you. There's a n efficient Versene for every chelation job — regardless of pH. Outline your situation. Ask for confiden tial chemical counsel, technical d a t a and the right sample.
THE DOW CHEMICAL COMPANY M I D L A N D
WAREHOUSE Chos. S. Tonner C o . , Chorlotte, N . C , G r e e n v i l l e , S. C , Kno; i11e, Τ · η η . Kraft Chemical C o . , Inc., 9 1 7 West 1 8th Street, Chicago 8 , I llin< Independent Chemical Corp., One Hanson Place, Brooklyn 17, Ν Sarada & Pose. Inc., Houston, Dallas, Corpus Christ!, New Orleai St. Louis, W i c h i t a , Oklahoma City, Tulsa, Kansas City, M o .
M I C H I G A N
^^w^»
STOCKS George Mann 4 C< , 251 Fox Point B l v d . , Providence, R. I . Broun-Kneeht-Heimonn C o . , San Francisco, C a l i f . , Salt Lake City. Utah Broun Corporation, Loi Angeles, California Van Waters & Rogers, I n c . , Seattle, W a s h . , & Portland, O r e . European Manufacturing Agent: Rexolinfobriken A k t i e b o l a g , Helsingborg, Sweden
For further information, circle number 24 A on Readers' Service Card, page 37 A
24 A
The Kinetics of the Formation of Slightly Soluble Crystalline Precipitates. JAMES D. O'ROURKE, University of Michigan, Ann Arbor, Mich., AND RALPH A. JOHNSON, Uni
versity of Illinois, Urbana, 111. The rate of precipitation from dilute solu tions is generally slow during the initial and final stages of precipitation and compara tively rapid during the intermediate stage. It is commonly believed that the final stage is controlled primarily by the growth reaction. However, the initial and intermediate stages have been represented as being controlled by both nucleation and growth, separately as well as together. Theoretical aspects of the precipitation process were discussed along with the effect of growth and nucleation on the final dispersion of the precipitate. Slow Precipitation Process. Louis GOR DON, Syracuse University, Syracuse, Ν. Υ. The rate of addition of a precipitant could be easily controlled by the technique of pre cipitation from homogeneous solution. For example, silver ion could be generated in a solution containing chloride ion at such a rate that it required about 8 days to precipitate 150 mg. of silver chloride. Such slow pre cipitation processes permitted near equilib rium to be established between the surface of the solid and the solution and made it posANALYTICAL
CHEMISTRY
NEWS sible t o d e t e r m i n e t h e n a t u r e a n d extent of coprecipitation. Applications of t h i s t e c h nique of precipitation were described in which Doerner-Hoskins d i s t r i b u t i o n coefficients h a v e been o b t a i n e d for systems containing b a r i u m - r a d i u m mixtures. O t h e r coprecipi t a t i o n studies were described, p a r t i c u l a r l y some which revealed t h a t t h e e x t e n t of c o precipitation w a s negligible except d u r i n g t h e initial a n d final stages of t h e p r e c i p i t a t i o n process. Significance of Rates and Equilibria in Electroanalytical
Chemistry.
JOSEPH
DAN, T h e P e n n s y l v a n i a S t a t e University P a r k , P a .
JOR
University,
Careful consideration of c u r r e n t - v o l t a g e curves, on t h e basis of N e r n s t i a n equilibria a n d kinetics, indicated t h a t reversibility a n d irreversibility were relative criteria which could be readily i n t e r p r e t e d in t e r m s of t w o competing r a t e processes: (a) t h e t r a n s p o r t of t h e electroactive species from t h e bulk of t h e solution t o t h e surface of t h e indicator electrode a n d (6) t h e electrode reaction strictu sensu—i.e., t h e electron transfer b e tween t h e electrode on t h e one h a n d , a n d t h e oxidized a n d reduced forms of t h e electroactive species o n t h e other. T h e corresponding relationships were illus t r a t e d b y e x p e r i m e n t s of " h y d r o d y n a m i c v o l t a m m e t r y " where c u r r e n t - v o l t a g e curves were d e t e r m i n e d in solutions which a r e a l lowed t o s t r e a m p a s t t h e indicator electrode with v a r y i n g flow velocities. B y adjusting t h e r a t e of convective t r a n s p o r t , ordinarily " r e v e r s i b l e " electrode reactions could b e m a d e irreversible over a n appreciable r a n g e of p o t e n t i a l s . Because t h e r a t e of electron transfer w a s a monotonie function of t h e p o t e n t i a l , " p u r e t r a n s p o r t c o n t r o l " prevailed whenever a t r u e limiting c u r r e n t w a s a t t a i n e d , irrespec t i v e of t h e a p p a r e n t reversibility or irreversi bility of t h e ascending p o r t i o n of t h e w a v e . C o n s e q u e n t l y , limiting c u r r e n t s m a y a l w a y s be applied with confidence t o q u a n t i t a t i v e analysis, since t h e r a t e of diffusive a n d / o r convective t r a n s p o r t w a s in all k n o w n i n stances p r o p o r t i o n a l t o t h e b u l k c o n c e n t r a tion of t h e electroactive species. Some Applications of Polarographic RateControlled Currents. K . W I E S N E B , U n i v e r sity of N e w Brunswick, F r e d e r i c t o n , Ν . Β . ,
ANALYST'S
CALENDAR
Gordon Research Conferences. I n s t r u mentation, New London, Ν . Η., July 25 t o 2 9 . Analytical C h e m i s t r y , N e w H a m p t o n , Ν . Η., August 8 t o 12. Symposium on Analytical Chemistry. M i d l a n d s Society for Analytical C h e m istry, U n i v e r s i t y of B i r m i n g h a m , Bir m i n g h a m , E n g l a n d , August 25 t o Sep t e m b e r 1. Fifth International Colloquium for Spec troscopy. G m u n d e n , S a l z k a m m e r g u t , Austria, August 30 t o S e p t e m b e r 3 . American Chemical Society. 128th Meet ing, Minneapolis, M i n n . , S e p t e m b e r 11 t o 16. Tenth Instrument-Automation Confer ence. I n s t r u m e n t Society of America, Los Angeles, Calif., S e p t e m b e r 12 t o 16. First International Instrument Congress and Exposition. Philadelphia, P a . , S e p t e m b e r 13 t o 25. Ottawa Symposium on Applied Spectros copy. O t t a w a , C a n a d a , S e p t e m b e r 20 and 21.
VOLUME
2 7, N O . 7, 1 U L Y 1 9 5 S
C a n a d a ; o n leave a t H a r v a r d University, Cambridge, Mass. A completely rate-controlled polarographic limiting c u r r e n t m i g h t b e recognized a n d distinguished from a diffusion-controlled polarographic c u r r e n t b y i t s i n d e p e n d e n c e on t h e height of t h e m e r c u r y reservoir. T h e r e m i g h t be, however, cases w h e r e d a t a derived from o t h e r e x p e r i m e n t s could be combined with d a t a derived from a r a t e - c o n trolled c u r r e n t t o furnish t h e u n k n o w n equi librium c o n c e n t r a t i o n of a reducible species. Such a case is, a t p r e s e n t , only t h e system of glucose. T h e polarographic reduction of glucose was a process controlled b y t h e r a t e of forma tion of t h e a l d e h y d e form from t h e a- a n d /3-glucose. Since it w a s possible t o d e t e r mine t h e rate-controlled c u r r e n t d u e t o t h e conversion of a- or /3-glucose into a l d e h y d e form separately, t h e a u t h o r s were in posses sion of t w o e q u a t i o n s involving t h e u n knowns ki, fci1, &2, a n d fc?1. T h e o t h e r t w o e q u a t i o n s needed t o calculate t h e values of these four c o n s t a n t s m i g h t b e derived from well-known d a t a on glucose solutions.
Have you tried thest Time-Saving
S'S FILTRATION AIDS? s*s FILTER PULP No. 289, Ash-Free Helps to mini mize clogging of the filter paper, and maintain fil t r a t i o n speed. Helps obtain better retention of precipitate, insure more accurate results. Dry-Dispersed form replaces moist pulp and brittle tablets. Send f o r f r e e b u l l e t i n
Conference on Industrial A p plications of X-Ray Analysis Specific applications of x-ray analyses in agriculture, mining, petroleum, glass, reclamation, pharmaceuticals, metal lurgy, and geological survey work will highlight the Fourth Annual Sympo sium on Industrial Applications of XRay Analyses. The two-day meeting will be held August 11 and 12, 1955, at the Albany Hotel, Denver, Colo. More than 20 papers will be presented by research workers associated with in dustrial firms, government agencies, universities, and research organiza tions. There will be other papers on general applications and basic research in the areas of diffraction, fluorescence, and absorption. Rooms are being held at the Albany Hotel for advance registration. A trip into the Rockies is scheduled for August 13. Further details are available from James P. Blackledge, Denver Research Institute, University of Denver, Denver 10, Colo. International Congress o n Analytical Chemistry A Congress on Analytical Chemistry will be held in Lisbon September 9 to 16, 1956, under the patronage of the International Union of Pure and Ap plied Chemistry. D. Antonio Pereira Forjaz has been appointed president of the Organizing Committee. Ar rangements for the meeting are in the hands of Pierre A. Laurent, Institute Superior Technico, Avenida Rovisco Pais, Lisbon, Portugal. The congress is intended to cover broadly all aspects of analj'tical chemistry. L. M. Kolthoff, Univversity of Minnesota, is president of the Analvtical Section of the Union.
s*s ANTI-CREEP Reagent Fluid A few drops added to $ASHL£ the wash solution Ann·*" prevents the "creep" of precipitates up the filter paper, facili tates the transfer of insolubles from the precipitation vessel, reduces the problem of film deposit on the walls of the beaker. Send f o r f r e e f o l d e r
s«s FILTER PAPER SUPPORTS No. 123 With these Supports even soft grades of Filter Paper can be submitted to high suction without danger of bursting at the apex. Special pure, porous textile material will not retard filtration. Inexpensive. Send f o r f r e e f o l d e r All three of these S&S Filtration Aids are time savers. They are available, with S&S High Quality Analytical Filter Papers, from your laboratory supply house. MAIL
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Circle Nos. 25 A-1, 25 A-2, 25 A-3 on Readers' Service Card, page 37 A
25 A
NEWS
Look w h o uses
GOLDFISCH fat extractors!
Analytical Techniques T h e 1955 Short Course on Analytical Techniques, to be held a t t h e Univer sity of Illinois, Urbana, 111., August 1 to 5, is being given b y t h e American Oil Chemists' Society in cooperation with t h e extension division of t h e uni versity. Application forms m a y be o b tained from t h e society's office a t 35 E a s t Wacker Drive, Chicago 1, 111. August 1 Welcome. G. A. G R A P P L E , Wilson a n d Co., Chicago. Sampling. L. R. B R O W N , A. E . Staley Manufacturing Co., Decatur, 111. Determination of Impurities. A. A. R O D E G H I E R , D u r k e e F a m o u s Foods, Chicago. Loss Determinations. Ε. Μ . J A M E S , Swarthmore, Pa. Color and Bleach Methods. R. C. S T I L L MAN, Procter & G a m b l e Co., Cincinnati, Ohio. Melting Solidification and Consistency. H . M. SMITH, Southern C o t t o n Oil Co., Chicago, 111.
• Wisconsin Alumni Research Founda
tion (above]
August 2
• Wilson and Company • The Borden Company • American Can Company
Flavor Evaluation. C. D . EVANS, N o r t h ern Regional Research L a b o r a t o r y , Peoria, 111. Stability and Rancidity. L E R O Y DUCIAS, J R . , American M e a t I n s t i t u t e F o u n d a t i o n , Chicago.
• State of California Feed Control • Schenley Distillers • • • •
Performance
General Mills Joseph E. Seagram and Sons U. S. Department of Agriculture Cornell University Experiment Station
E M E R Y C.
SWAN-
SON, Pillsbury Mills, Springfield, 111. X-Ray Spectroscopy. W. S. SINGLETON, Southern Regional Research Laboratory, New Orleans, L a . Ultraviolet Spectroscopy. R. T. O ' C O N NOR, Southern Regional Research Labora tory, N e w Orleans, La. Infrared Spectroscopy. R. F . O'Connor, Southern Regional Research Laboratory, New Orleans, La.
Using the Goldfisch solvent process f a t extractor, you, too, get results in 2 to 4 hours that used to take all d a y Due to automatic release and seal of the condensation chamber, vapor ized solvent quickly condenses, thus speeding extractions.
August 3 Dilatometry. W . Q. B R A I N , Wilson a n d Co., Chicago. Chromatography. R. R. A L L E N , Armour and Co., Chicago. Fractional Distillation. A. W . W E I T K A M P , S t a n d a r d Oil Co. ( I n d i a n a ) , Whiting, I n d .
The modern Goldfisch reclaims a high percentage of solvent . . . operates safely in open rooms . . . soon pays its way in time and money saved.
August 4 Fractional Solvent Crystallization. J. B . B R O W N , Ohio S t a t e University, Columbus, Ohio. Craig Countercurrent Extraction. H . J. D U T T O N , N o r t h e r n Regional Research L a b o r a t o r y , Peoria, 111. Microscopy. C. W. H O E R R , A r m o u r a n d Co., Chicago. Instrumental Analysis : Automation.
FREE ILLUSTRATED BOOKLET W r i t e today for prices and free
Testing.
LEWIS
MALTER,
Beckman
Chicago, 111. Statistical Methods. Swift a n d Co., Chicago.
illustrated
booklet with full descrip
Instruments.
H. P.
ANDREWS,
tions and installation pic
August S
tures of f a t , fiber and protein apparatus.
Measurement of Chain Length. F . A. K U M M E R O W , University of Illinois, U r b a n a . Measurement of Unsaturation. R . R. A L L E N , Armour a n d Co., Chicago. Determination of Hydroxyl Groups. E D
Ask
for booklet K - l .
Laboratory Construction Company 1109 Holmes Street
•
Kansas City, Missouri
·
WARD H A N D S C H U M A K E R , Tenafly, N . J.
Determination of Triglyceride Structure. R. W . R E I M E N S C H N E I D E R , E a s t e r n Regional Research L a b o r a t o r y , Philadelphia. Process
Control.
WALTER
TRENT,
gate-Palmolive Co., Jersey City, N . J.
Col
Establishment of Specifications and Stand ards. C. E . M O R R I S , A r m o u r a n d Co., Chicago.
T h e fall meeting of t h e society, to be held in Philadelphia October 10 t o 12, will also emphasize analytical tech niques.
Nuclear Magnetics Corp. T h e Perkin-Elmer Corp. h a s formed a new subsidiary, t h e Nuclear .Mag netics Corp., t o m a r k e t nuclear mag netic resonance equipment. Manu facturing operations will be conducted in Norwalk, Conn., research and de velopment in Boston.
NEW BOOKS A Manual of Paper Chromatography and Paper Electrophoresis. Richard J. Block, Emmett L. Durrum, and Gunter Zweig, viii a n d 484 pages. Academic Press, Inc., 125 E a s t 23rd St., New York, Ν . Υ., 1955. $8. Reviewed
by
H A R O L D G.
CASSIDY,
Yale University, New H a v e n , Conn. This book consists of two p a r t s . T h e p a r t on paper electrophoresis, by E . L. D u r r u m , is entirely new; t h a t on paper chromatography, b y R. J. Block a n d G. Zweig, is largely new b u t contains essentially t h e same foreword, intro duction (Chapter I ) , a n d theory (Chap ter I I ) as t h e earlier book " P a p e r Chromatography. A Laboratory M a n ual," by R. J. Block, R. Le Strange, and G. Zweig (1952). F r o m Chapter I I I on t h e differences from t h e earlier volume become progressively more marked as t h e authors take u p t h e newer techniques t h a t have been de veloped since t h e earlier volume was published. T h e authors, having designed this book as a manual for t h e laboratory worker, have wisely n o t a t t e m p t e d to include references t o all t h e literature. (A recent European book on paper chromatography lists 3795 references.) Moreover, t h e y give t h e user t h e bene fit of their j u d g m e n t a n d experience by pointing o u t in some instances those procedures which are recommended. This a n d t h e initial sorting of t h e literature are important services ren dered to t h e user of this book. T h e various laboratory procedures, some of t h e m very detailed, are organized by classes of compounds of similar func tional type, such as amino acids and carbohydrates, covering t h e entire field of organic and inorganic substances very completely. T h e directions for prepa ration of samples, chromatographic techniques, methods of detection of zones, and preparation of solvents and
Circle No. 26 A on Readers' Service Card, page 37 A
26 A
ANALYTICAL
CHEMISTRY
