ANALYTICAL CHEMISTRY
1128 strictly to prescribed directions. The comment concerning gold precipitated by amidol may thus be explained. The data and research impetus fully justify t h e existence of this book, but t h e presentation is not embellished by some of F. E. BEAMISH t h e defensive comments.
Qualitative Analysis and
Analytical
Chemical
Separations. 223 pages. Macmillan Co., 60 Fifth Ave., Kew York, S. Y., 1953. Price. 83.75.
P. W . W e s t , M. M. Vi&, and A . L. LeRosen. xii
+
A new approach to qualitative analysis is presented in this text. A nonsulfide scheme has been developed, retaining the pedagogical advantages of the traditional course in qualitative analysis, and, at the same time, introducing techniques of real analytical value. This scheme seems t o have the merit of sharper group separations with more efficient (rapid) techniques. The special phosphate modification is unnecessary. Seminiicromvthods are used with the standard chemicals and apparatus. Preliminary experiments with the individual ions precede the directions for the analytical separations to emphasize the chemistry of the cations. However, little emphasis is given t o the systematic analysis of the anions (8 pages). In the larger section of the book in which theoretical principles are discussed, modern concepts are freely used. For example, the authors mention brirflv the Br9nsted theory, thus affording the instructor an opportunity to amplify the subject. They are not afraid to use the words “orbitals” and “hydrogen bonding.’’ Coordination compounds and Werner’s theory are adequately discussed, including the rules of nomenclature and diagrammatical representations of structures. Chemical equilibria and related topics are clearl!- presented, with numerous problems Forked out in detail. Each chapter has sufficient questions and problems with answers to afford a variety in assignments. The book is well balanced in its presentation for an introductory rourse in qualitative analysis. THOS.D E VRIES
MBthodes et Reactions de 1’Analyse Organique. M . Persez and P. Poirier. Edited by Leon Velluz. Volume 11. 278 pages RIasson e t Cie, 120 Boulevard Saint-Germain, Paris 6, France, 1953. Price, 2500 francs. This is the second of a three-volume sequence devoted to the qualitative and quantitative analytical aspects of organic chemistry. The present issue contains the most complete description of the chemical methods and reagents used for the characterization of organic compounds now available. The organization of this book is unusual. Division into chapters is based on t h e process involved in the characterization procedure rather than on a consideration of the functional groups. This leads to the anomalous situation where derivatization of alcohols, for instance, is discussed in chapters entitled: -4lkylation and Arylation, Carbamates and Allophanates, and Salts and Addition Compounds. This approach can only increase the principal difficulty in the characterization process-i.e., the choice of a derivative. Within the chapters, the arrangement of material is more logical. The principles of the processes involved are discussed first. Each class of compound is considered separately. Some of the limitations of the methods are included. These sections are followed by detailed descriptions of the preparation and use of a wide selection of reagents. Tables of physical constants of derivatives conclude each chapter. As a working manual, this volume will probably have very limited value t o American analysts. The separation of mixtures is not discussed. The characterization of hydrocarbons receives little attention. Considerable space is devoted to the synthesis
of reagents, many of which can be purchased. The tabular material is only slightly more extensive than t h a t found in standard qualitative organic texts. The book is well documented and the experimental procedures are described clearly. STUARTW.FESTOX
Society for Applied Spectroscopy
THE
eighth annual meeting of t h e Society for Applied Spectroscopy was held M a y 14 and 15 in S e w York. The program included a Symposium on Future Possibilities for Spectroscopic Instruments, contributed papers on applied spectroscopy, and an exhibition of laboratory equipment. Secretary of the society is C. .4. Jedlicka, U. S. Testing Co., Inc., Hoboken, N. J. Infrared Method for Determination of Alpha (2,4,6), Beta (2,3,4), and Gamma (2,4,5)-Trinitrotoluene and 2,4-Dinitrotoluene in Admixtures Such as Found in TNT Exudates. FRANK PRISTERA, Picatinny Arsenal, Dover, N. J. An infrared method has been developed for determination of cy, @, and y-trinitrotoluene (TKT) and 2,4-dinitrotoluene (DNT) in admixture. The method has been applied t o synthetic mixtures where the a-TNT ranged from 70 to 94% and the B-TKT, y-TNT, and 2,4-DXT each ranged from 2 to 10%. The measured absorbances, after being corrected for solvent and cell absorbance, were calculated to per cent of cy, p , and -/-TNT and 2,4-DNT by the method of successive approximations. Identification of Complex Organic Materials by Infrared Spectra of Their Pyrolysis Products. DOXALD L. HARMS,General Electric Co., Schenectady, N. Y . Because of the physical intractability of some rubber, plastic, and resinous material, a pyrolysis method of infrared sampling has been studied. Natural rubber, synthetic elastomers, and a variety of thermoset and certain insoluble thermoplastic resins were pyrolyzed a t 375’ to 750’ C Infrared spectra showing distinctly unique features were obtained from the liquid pyrolyzate. Reproducible spectra were consisteiitly obtained from several samples of each of a number of materials which heretofore have resisted the customary procedures used in preparing samples for infrared analysis. Six examples of the pyrolyzate-infrared approach t o typical problems were described in order to illustrate the unusual rapidity and utility of the procedure as compared to any other known method. Absorptive Studies in the Vacuum Ultraviolet. LUCYW PICKETT, Mount Holyoke College, South Hadley, Mass. The paper covered a brief review of the nature of material absorption in the near-vacuum ultrariolet. Continuous Flow Method for Determining Ionization Constants by Ultraviolet Spectrophotometry. F. T. KINGAND R . C. HIRT, American Cyanamid Co., Stamford, Conn. An apparatus was described for determining ionization constants by ultraviolet spectrophotometry. The system consists of a glass and Tygon pump which circulates the solution being titrated from a closed, thermostated titration flask containing electrodes, stirrer, and thermometer, through an absorption cell in the sample compartment of a Cary spectrophotometer. The apparatus, tentatively called a Spectrotitrimeter, eliminates the use of buffer solutions and offers greater speed and freedom from interferences than the classical method. Application of the A.R.L. Quantometer t o Production Control in a Steel Mill. H. C. BROWN, Armco Steel Corp., Butler, Pa. This paper described the use of the 4 . R . L . production control quantometer in the Butler, Pa., plant of the Armco Steel Cow. since April 1952. The Quantometer is used to analyze preliminary and ladle test samples from six open hearth furnaces and one electric furnace. A history of the installation and calibration of the instrument was given along with the standard procedures now being used. Data were given to show accuracy and reproducibility of results for silicon and stainless type steels. Spectrochemical Method for Analysis of a Nickel-Base High Temperature Alloy for Aluminum, Titanium, Silicon, and Manganese. Standardization by Wet Analysis. Standardization by Powdered Metal Briquets. W. H. TOBINAND IT. 0. GERBER,J R . , General Electric Co., West Lynn, Mass.
1129
V O L U M E 25, NO, 7, J U L Y 1 9 5 3 A point t o plane spark technique was described for the determination of manganese (0.5-2.0%), silicon (0.5-2.0%), titanium (1.3-3.070) and aluminum (0.2-1.0%) in a nickel base (53.7,) alloy containing also, additions of chromium, molybdenum, cobalt, and iron. Exposure conditions for the Jaco 3.4-meter spectrograph and the General Electric Spectrosource as well as t h e effects of electrode separation and sample volatility were discussed. Analytical curves for the elements titanium, aluminum, manganese, and silicon were shown. Precision and accuracy data were also included. Several man-hours are saved as opposed to analysis by wet methods. Because of the scarcity of standards and the difficulties and time ronsumption in the wet analysis of standards, this laboratory has developed a procedure for preparing standards by the use of powder metallurgy. B y the use of special techniques, element retention after melting is such that added percentages can be used as final percentages. Application of this technique t o the analysis of the elements tungsten, niobium, and molybdenum combination in 5-816 cobalt base high temperature alloy; tungsten, niobium, molybdenum. silicon, aluminum, and tin in stainless steels; titanium and manganese in aluminum has been described in previous papers by the coauthor. The applicability of this technique to the analysis of titanium, aluminum, manganese, and silicon in the nickel-base alloy described above was discussed. Spectrographic Determination of Impurities in Eutectic Alloy of Cadmium-Tin. G. E. PETERSON ASD E. W. CURRIER, Telecommunication Laboratories, Nutley, E.J. A spectrographic method was given f o r the quantitative determination of bismuth, copper, iron, lead, silver and thallium in the eutectic alloy of cadmium and tin. The nolninal impurity range covered by this method of analysis is from 5 to 100 parts per million. Spectrographic Analysis of Potassium in Urine and Feces Using Copper Electrodes. 122. H o s ~ AXD a J. D. O'CoNh-oIt U S.Kava1 Radiological Defense Laboratory, San Francisco, Calif A spectrographic method for the determination of various dements in urine aiid feces has been developed using the copper spark method. This study is concerned with the rapid determination of potassium simultaneously with several elements. Since most of the sensitive lineh of the various elements occur in the ultraviolet region. the deterinination of potassium had to be done in this region. The copper spark method eliminates the troublesome cyanogen spec1rii in the ultraviolet, thus enabling the use of the 4047.2 A. line 0 1 potassium for analysis. Reproducibility data were presented and the spectrographic method w a h compared t o the conventional gravimetric perchlorate method. The results indicate fairly close correlation. The solution method ha3 been used throughout this work and modified techniques in the handling of standard and analysis were dexribed. This procedure is well adapted for use in routine determination of potassium in ashed urine and feces samples. Logarithmic Sector us. Photoelectric Densitometer in Measuring Intensity Ratios. MILTOXGREEXAND MURRAYL. POLK,Signal Corps Engineering Laboratories, Fort Monmouth, N. J . The relative intensities of a group of ten lines of the spectrum of a hydrogen discharge tube have been measured both by conventional photoelectric densitometry and wkh a logarithmic sector. A statistical analysis of the results showed that, for our instruments, photoelec,tric densitometry is slightly more accurate than logarithmic sector intensitometry; the former method gives an average coefficient of variation in the measurement of an intensity ratio of 2%, whereas the latter method gave an average coefficient of variation of approximately 4%. However. for a great many applications in spectrochemical analysis the latter method appears to be sufficiently accurate, a t the same time having many advantages. I t is faster and simpler; intensity ratios are obtained directly without the need of a calibration curve; the method is self-calibrating; it does not involve a considerable amount of complicated equipment that requires frequent attention; intensity ratios can be made over a much greater range for a single exposure of the spectrum. New Monitored Beam Recording Densitometer and Comparator. FREDERICK BRECHAND L. P. NEAL,Jarrell-Ash Co., Yen-tonville, Ma>.s. The Jaco recording microdensitometer has been redesigned to achieve a double-beam instrument. Two photomultipliers fed from a common high voltage source are employed, one each in the reference and analytical channels. The output from each is fed through separate circuits to a ratio recorder developed especially for this purpose. -4panel meter is also employed. Clear plate stability is within 1 0 . 5 7 0 and long-term drift has been alnioat wholly eliminated. Full scale deflection may be achieved for
an effective slit area of 5 X 3 mu. whereas at a slit size of 12 X 125 mu. optical densities higher than 3 may be measured. Continuous plate sranning and multispeed selection between 0.05 and 25.0 mm. per minute on the current design have been preserved. but the body of the instrument is being redesigned to afford greater convenience in the use of the comparator features. Methods for Direct Spectrographic Analysis of Lubricating Oils. J. T. Rozs.4 AND L.E. ZEEB. Xational Spectrographic Laboratories, Inc., Cleveland, Ohio Various methods were discussed for the direct analysis of lubricating oils for wear products, including comparisons of sensitivity and precision. Spectrographic Determination of Trace Impurities in Water. NEIL E. GORDON, JR.,A?UD HAROLD D. COOK,Westinghouse Electric Corp., Pittsburgh, Pa. A spectrochemical technique was presented for the simultaneous determination of the following impurities in water: aluminum, calcium, cobalt. chromium, copper, iron, magnesium, sodium, niobium, silicon, tantalum, and zirconium. The method requires only 260 ml. of sample and is applicable to most of these impurities over the range of 0.001 to 50 parts per million with a precision of +30%. A salt technique is utilized in conjunction with d.c. arc excitation. Cadmium is employed as an internal standard and high purity graphite powder is added as a combination carrier and buffer. Adsorption of the cations on the polyethylene sampling equipment is minimized by adjusting the acidity of the sample Kith specific acids.
Society of Public Analysts HE
41st ordinary meet,ing of the Physical Methods Group of
Tthe Society of Public Analysts and other Analytical Chemists
was held M a y 8 in Ipswich. This was a joint meeting with the E a s t Anglian Section of the Royal I n s t i h t e of Chemistry. The following papers on emission spectroscopy were presentpd and discussed. Semiquantitative Techniques in Spectrochemical Analysis. R. L. hfITCHELL. There is often a need for something between a purely qualitative examination of a sample and an exact, time-consuming, quantitative determination of one or more constituents. Several spectrochemical procedures which can provide the necessary information have been described. In this respect spectroscopic methods are generally somewhat more flexible than other analytical procedures. The semiquantitative approach is particularly valuable for the survey of a number of constituents in a large numher of samples. The approach t o the problem has varied Kith different workers, and several of the methods suggested were reviewed. That in use a t The Macaulay Institute for Soil Research for estimations of this type, partirularly in soils, rocks, and minerals, involves cathode layer excitation, followed by visual omparisonof the spectrograms with those of standard samples of like matrix composition in a spectral line comparator. Some Techniques of Presentation of Sample to the Spectrograph. A. H . C. P. GILLIESON. Four methods of sample presentation were described-three arc and one spark. They are all essentially methods for detection and estimation of trace elements: two are quantitative. the others semiquantitative: copper-arc using flux plus sample, carrier-distillation d.c. graphite arc, hollow cathode discharge tube, and copper spark plus sample solution. The first is a quantitative method of wide application suitable for ashes, a wide variety of element oxides or other compounds-plant ignited soils, and ores. The second is suitable for the determination of impurities in refractories-alumina, beryllia, etc. The third, for which either solid samples or solutionq may be used, is particularly useful for the determination of the halides, but will also determine the alkali metal- and sulfur. I t can be applied direct to organic materials. The last-a solution method-is of wide application where the amount of material available is very small in quantity. Applications of the Porous Cup Technique. L. G. YOUKG. A modification of the porous cup technique of Feldman has been applied to the determination of a major constituent-zinc in brass. Details include the preparation of electrodes, analytical procedure,
1130 and a new electrode stand designed for this work. Tables showing the reproducibility and ~ C C U P B D Yof single determinations were presented. Mention was made of other metallurgied samples analyved and of various diffioulties already overcome in the application of the method t o the complete snalysis of soluble miscellaneous residues rtshas, and corrosion products.
An ordinary meeting of t h e society was held May 20, in London. T h e following papers were presented and discussed. Determination of Ergosterol in Yeast. W. H. C. SXAWINDJ I’ JEPFERIES.
ULTRA~IOLET ASSORPTION OF PURXFIED ERGOSTEROL. Most published records agree on the wave lengths of the three main peaks in the ultraviolet absorntion curve of erzosterol. but there are discreeancies in the extinction values reported for the various maxima. apparently beoause of the diffioulty of preparing pure ergosterol by direct recrystdlisation of the commercial material and t o a lesser extent because of small variations in the moisture content of the hydrated sterol. Simple recrystallisation does not ralws,ys yield a pure product; the best means of purifioation is by recrystallising a suitable ester, with subsequent regeneration of the sterol. The preparation and purification of ergosterol benzoate were described and the physical properties and ultraviolet %hsobsorption (in various solvents) of s purified speoimen of ergosterol were recorded. DETEBMINAT~ON BY SAPONIFICATION AND ULTRAYLOLET ass on^ T ~ SPECTROBCOPY. N Part of the ergosterol found in yeast occurs in a combined form, and treatment to liberate the free sterol is a %acesmry preliminary to its determination. Most published methods make use oi alcoholic or aqueous alkali hydroxides for this purpose. and the variety of strengths prescribed suggested that further investigation was necessary. The oonditions for the destruction of the yeast cells and maximum reoovery of ergosterol have been studied. Boiling under reflux with alcoholic sodium or potassium hydroxides did not break down the yeast sufficiently. Aqueous sodium hydroxide a t strengths from 10 to 50% w./w. gave low a i d erratio results. additiond ergosterol being recovered by subsequent alcoholic saponification of the residue. Concentrations of potassium hydroxide above 20% w./w. i n aqueous solution proved sstiefactory. the strength required depending on thelength of boiliigunderreflux. For the method described 40% w./w. aqueous potassium hydroxide has been selected. as it makes possible eonsidemble latitude in time and concentration The ergosterol in the extracted unsqponifiable matter is Separated hy digitonin precipitstion from nonsterol substances that show irrelevant absorption in the same region as ergosterol. This preoipitation has been shown to be quantitative, the separated sterol digitonides iielding solutions speotroseopically indistinmishable at wave Iewths above 260 ma from those of purified ergosterol. CoRREcnoNs FOR IRRELEv*NT ABBORPTIONI N SOLUTIONS O F Encos~mno~.The unsaponifiable matter of yeast normally oontains substances that po6sess ultraviolet absorption in the same region as ergosterol. so that the ertinct,ion at the ergosterol maximum (282 mi” in absolute alcohol) cannot be used directly as a measure of the eonoentration of ergosterol present. Although digitonin purifiestition may be used for separating ergosterol in a spectroscopically pure oondition. considerable time can be saved by applying a cormction prooedure to the gross absorption. , Two suoh prooedures have been studied: (1) a eorreotion of the Morton and Stubbs type. based on the 282-mi” maximum m d two subsidiary wave lengths at which the purified compound ~ossesszs maximum absorption, and (2) a new four-point correction based on the three ergosterol maxima (271.5, 282, and 293.5 ma) with 8. fourth reading at 310 mi”, where eraosterol shows very little absorption. Procedure 1 suffers from the disadvantage that the maxima in the absorption curve of ergosterol are sharp and observations a t the subsidiary wave lengths must be taken on steep portions of the curve. In omsequence, small errors in measuring wave lengths have a large effect on the oorrection factor and any instrument used for this procedure must be calibrated with pure ergosterol. Procedure 2 is free from this disadvantage but requires 8; greater range of wave lengths and linearity of absorption must be assumed over it. Results by both corrective procedures were compared with those by t h e full digitonin method. The degree of agreement is generally good, but depends on the shape and amount of irrelevant absorption, which ha8 been determined on %numberof differentstrains of yeasts. Snom METXODBASEDON U m a n v i o m ~ABSORPTION.The &eourate method for determining ergosterol in yeast described above has proved too lengthy for the examination of large numbers of samples. A short semimioromethod involves saponifying a portion of the yeast sample oontsjning about 1 mg. of ergosterd with a small volume of 40% w./w. aqueous potassium hydroxide in a epeoially designed flask and extracting the unsaponifiable matter with a single
A N A L Y T I C A L CHEMISTRY accurately measured volume of oyoloheamne. The filtered extraot is suitable for speotroscopic enaminhtion. The four-point correction procedure is applied to allow for irrelevant absorption; the ergmterol content of the sample is calculated from the corrected extinotion a t 252 ma (man.). The method requires much less manipulation time than the full digitonin procedure but. because a geometrical correction and a single extraction only are used. gives results slightly lower and n standard deviation of .s single determination a little greater than sre go%with the full method.
The Estimation of Micro Quantities of Calcium. G. E. HAREISON W. H. A. RAYMOND. A micromethod for the estimation of odoium is based on the colorimetrio estimation of a molybdenum thiooyanate. An aceur~oyof bett.er than 10% is attained for solutions containing as little as 4 y of calcium. The method is especially useful for the estimation of serum calcium in young children or smaI I laboratory mimals. A comparison of the results with those found by other methods was AND
given. Ultraviolet Spectrophotometric Estimation of the Quality of Mineral Oils Extmeted fmm Bread. M. A. C O O X ~ J. I NB. , M. COPPOCX, AND R. S C ~ N U W A N N . A method has been developed hy which the degree of refining of a mineral oil that has been absorbed by a dough during bread making may be determined in the resultant bread. The method consists basically of sulfating. under controlled conditions, the unsqponifiable fraction of the total oils extracted from bread, 80 that the natural saponifiable matter is destroyed without completely removing the unsaturated hydrocarbon constituents inherent in mineral oils of different degrees of refining. The recovered mineral oil is then examined by ultraviolet absorption speotrophotometry to determine its quality. A spectrophotometric criterion was suggested for the wa1ity of mineral oils that could be regarded as satisfactory for the lubrication of plant used in bread production.
Merck Fellowship Award Donald H. Vilkins of Park Rapids, Minn., a graduate student at the University of Illinois, was selected for t h e fifth annual $2500 Merrk Graduate Fellowship in Analytical Chemistry. Farrington Daniels, President of the AMERICAN CHEMICAL SOCIETY, presented t h e award at the 123rd meeting of t h e Society in Los Angeles, Calif. Mr. Wilkins, who received his M.S. in 1052, has completed two years of research under t h e supervision of G. Frederick Smith. Pending publications resulting from this work are on t h e following subjects: a new copper-specific reagent; 2,4,6-trinitrobeneoic acid as n primary standard in acidimetry; and D. Wi’kins spectrophotometrio studies of substituted 1,lO-phenanthrolines as their ferrous chelate complex ions. He will continue t o work rtt the University of Illinois on t h e chelate complexes of various series of compounds with spec metric reagent.8 for t tion indicators, and a
Microdetermination of 3-(p-Chlorophenyl)-l,ldimethylurea in Plant Tissue-Correction In the article on “Microdetermination of 3-(p-Chloraphenyl)1,l-dimethylurea in Plant Tissue” [Young, E. Y., and Gortner, 5’.A,, AXAL.CHEM.,25, 800 (1953)l in the sixth line under t h e heading Reagents, the listing should hawe been: N-(1-Xaphthyl). ethylenediamine dihydraehloride, 2%.
