V O L U M E 2 2 , N O . 3, M A R C H 1 9 5 0
Short Procedure for the Determination of Sulfaquinoxaline in Feeds SIR: The determination of sulfaquinoxaline in commercial feeds as desc1il)t.dby Tyler, Brooke, and Baker [ h s a t .C m x . , 21, 1091 (1949)l can be materially shortened by modifying the tcchrrique of preparing the extract. Extraction. One gram of feed (0.75 to 1.5 mg. of sulfaquinoxaline) ground to pass a 1-mm. sieve is transferred to a 100-ml. glass-stoppered volumetric flask, and 25 ml. of boiling sodium hydroxide (5 nll. of 2.5 Ai sodium hydroxide in 1000 ml. of distilled wakr) are added. The mixture is swirled to effect solution and diluted with 25 mi. of distilled water. Then 18 ml. of 1570 trichloroacetic acid (15 grams per 100 ml.) are added, and the solution is diluted to volume with distilled water, shaken well, and allowed to stand for 5 minutes. It is filtered through an 11-em. S. & S. 597 filter paper. The first 10 ml. are discarded and color is developed as described by Tyler, Brooke, and Baker.
501 pH measurement, deternilnation of ammonia, nnd estimation of manganese in steel. The final chapter includes turbidimetry, nephelometry, electrodeposition n ith a procedure for copper, potentiometric titration, conductometric titration, polarography, emission spectroscopy, x-ray and electron diffraction methods, physical constants, and a selected bibliography. These topics receive only brief description in the ten pages that are allotted to them. The appendixes deal with matheniatical operations, standardization of Teights, and statistical treatment of data, and tabular material is given on the t. m f sciies, solubility products, ionization and complex dissociation constants, specific volume of water a t various temperatures, and atomic weights. Indicator solutions are tabulated in the final appendix, and the color intervals are shown inside the back cove1 . There is no table of logarithms. Review questions or problems or both are provided for most of the chapters. The total number of problems is not large, nor are answers given for any of thrm. The type is rather small and the procedures are set in still fincr piint. The procedures are quite abbreviated. The authors and publishers have apparently done a very thorough job of proofrrading. N. H. FURMAN
Introduction to Semimicro Qualitative Analysis. C. H . Sorum. ix 196 pages. Prentice-Hall, Inc., 70 Fifth Ave., Sew York, K.Y., 1949. Price, $2.65. The above changes do not affect the accuracy of the deterThis book is written as a text for a one-semester course, and mination and reduce the time required to complete an analysis according to its author was designed particularly for use in laboraby one half. tory work accompanying the usual lecture coverage of the second S. W. TYLER R . 0. BROOKE semester of general chemistry. As might be expected of a text Wirthmore Research Laboratory hialden 48. M a s s W. S. BAKER written for use in the first year of chemistry, little theory is included. The cation separations are made according to conventional schemes. Anions are classified by means of preliminary tests, and final evaluation is then made by interpretation of information gained during the cation analysis together with that obtained by certain “specific” tests for anions. Some teachers will miss the use of preliminary exercises. -4number of loose statements appear, such as the statement (page 16) that a normal solution of orthophosphoric acid contains A Basic Course in the Theory and Practice of Quantitative one third the molecular weight of the acid per liter; on the next Chemical Analysis. George L . Clark, Leonard K . S a s h , and page the weight of salt to be used to make 1 liter of normal soluRobert B. Fisher. xxii 448 pages. W. B. Saundere & tion is determined by dividing the molecular weight of the salt by Co., Philadelphia, Pa., 1949. Price, $4.25. the total valence of the negative radical. Gnqualified statements This text is a rather brief one that is planned to cover the introsuch as the one declaring that all metal chlorides are soluble exductory year of quantitative chemical analysis. The authors, cept those of silver, mercury I, and lead may avoid confusing after two preliminary chapters, follow the order: gravimetric students but are somewhat disturbing. The above criticisms are analysis, volumetric analysis, colorimetric analysis. Approxinot to be construed &s condemning this book-many teachers mately 90% of the text, exclusive of appendixes, is devoted prefer to avoid certain exceptional cases and confusing details. to conventional gravimetric and volumetric methods and the The laboratory directions seem clear and reliable. The conaccompanying theory. firmatory tests are especially good: in a number of cases organic In comparison with other more or less similar texts, this one reagents are used. Throughout the book the author has made devotes relatively more space to volatilization methods, to the role liberal use of explanatory notes and equations are presented for of water of hydration or adsorbed watw in quantitative work, most of the important rcactionp studied. PHILIP W.WEST and to the theory of precipitation. Three chapters are given to the last topic. The chief gravimetric determinations that are drA.S.T.M. Standards on Textile Materials (with Related Inscribed in great detail are those of chloride, sulfate, and iron ill formation). A S . T.M.Committee D-13 on Textile Materials. simple mixtures. The section on separations and the analysis of xii 5’74 pages. American Society for Testing Materials, 1916 limestone and brass is a very brief one, of only 14 pages. Race St., Philadelphia 3, Pa., 1949. Price, $4.50 (paper). In the volumetric section the preparation and use of standard solutions of the following substances are dealt w:th: acid, alkali, The 3-11 members of Committee D-13, through their 21 subsilver nitrate, ammonium thiocyanate, potassium permanganate, committees, have guarded well the high standard for standards potassium dichromate, ceric sulfate, sodium thiosulfate, and iomaintained by the A.S.T.M. Their care and skill are manifest in dine. A brief account of potentiometric titrations is included the 51 standards and 33 tentative standards (cotton 23, ~ ~ o 11, o1 under the theory of oxidation-reduction titrations. The procerayon and silk 9, asbestos 7 , glass 6, bast and leaf fibers 5, general dures given are for the most part those that are traditionally inand test methods 23) for 1949. cluded in similar courses. An acidimetric procedurc is, however, Accessory features are presented in three glmsaries, eleven given for aluminum by the fluoride complex method. appendixes, three papers on x-ray studies, and several lists of The final section of the text proper consists of two chapters (22 publications and of committee officers or members. These features rank high in utility as supporting material for the standards pages). One chapter deals with colorimetry and touches on filter photometry and spectrophotometry. Procedures are given for and even as reference sources on their own.
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